Materials Science · Cross-listed from physics.comp-ph
A unified variational framework for phase-field fracture and third-medium contact in finite deformation hyperelasticity
Jaemin Kim, Gukheon Kim, Sungmin Yoon et al. (+1 more)
This paper presents a unified variational framework that integrates phase-field fracture (PFF) and third-medium contact (TMC) within finite deformation hyperelasticity. The key idea is that both crack and contact are treated through regularization: the sharp crack
topology is regularized into a diffuse damage field, while the discrete contact interface is regularized by a compliant fictitious medium with auxiliary fields. This strategy eliminates the need for explicit contact detection or crack tracking
algorithms. The framework is validated through two-dimensional three-point bending and three-dimensional Brazilian disk test simulations, demonstrating the interplay between contact-induced stress concentration and crack nucleation/propagation. In particular, the Brazilian disk simulation naturally reproduces secondary crushing-type fracture zones near the contact regions – a phenomenon consistently observed in experiments yet inaccessible to simplified loading models. These results pave the way for predictive simulation of coupled contact-fracture phenomena without recourse to explicit interface tracking.
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All authors Jaemin Kim, Gukheon Kim, Sungmin Yoon, Dong-Hwa Lee
Materials Science · Cross-listed from physics.bio-ph
Advancing Food Nanotoxicology with Microphysiological Systems: Rebalancing the Risk/Benefit Ratio Toward Safer Nano-Enabled Food Innovations
Georges Dubourg
Incorporating nanomaterials into food products provides key benefits, including extended shelf life, improved safety, and enhanced quality and texture. These innovations could help tackle major challenges in modern food systems, such as reducing waste and enhancing food quality and safety. However, potential toxicity remains a concern, compounded by the lack of physiologically relevant models for assessing ingested nanomaterials. Traditional in vitro and in vivo approaches often fail to mimic gastrointestinal complexity, resulting in inconsistent and non predictive nanotoxicity data that hinder accurate risk assessment of nano enabled foods. To address this gap, this review evaluates the potential of microphysiological systems (MPS), particularly gut-targeted MPS, for modeling gastrointestinal nanoparticle exposure. It examines how MPS technologies replicate key physiological processes relevant to food specific risk assessment, including intestinal barrier function, microbiota immune interactions, and gut organ communication. A comparative analysis of technological advances and their applications in nanotoxicology explores how MPS can be better adapted for nanofood safety evaluation.
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Materials Science
Thermal conductivity of CdCr$_{2}$Se$_{4}$ ferromagnet at low temperatures: role of grain boundaries and porosity
Jiří Hejtmánek, Kyo-Hoon Ahn, Zdeněk Jirák et al. (+5 more)
It is unambiguously demonstrated that the low temperature
magnon specific heat in a ferromagnet varies as T$^{3/2}$ and the
magnon thermal conductivity, due to T$^{1/2}$ - dependent effective velocity of
magnons, as T$^{2}$. The confirmation of these model comportments is based on the experimental study of chalcospinel CdCr$_{2}$Se$_{4}$, which represents relatively rare example of a
ferromagnetic insulator (T$_{C}$ = 130 K) without undesirable masking contributions of the itinerant electron excitations and
nuclear specific heat that both make impossible to conclusively unveil the role of
magnons. The ratio of the
magnon to
lattice specific heat is found to reach 87:13 at 2 K and is in accordance with predictions based on the
spin-wave stiffness D = 33.5 meVA$^{2}$ and Debye temperature ${\theta}_{D}$ = 237 K. On the other hand, the ratio of the
magnon to
phonon thermal conductivity reaching 27:73 at 2 K is much lower than expected for standard model of the grain boundary limited transport. This suggests that mean free paths for long-wavelength
magnon/
phonon heat carriers are largely different - shorter than the grain size (of 1${\mu}$m) for
magnons and longer than grain size for
phonons. The
phonon dominated low temperature thermal conductivity exhibits, moreover, a T$^{2.3}$ temperature dependence instead of the standard predicted model in T$^{3}$. The relevant scattering mechanisms, both the
phonon frequency independent and dependent ones, are discussed in detail.
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All authors Jiří Hejtmánek, Kyo-Hoon Ahn, Zdeněk Jirák, Petr Levinský, Jiří Navrátil, Sandy Al Bacha, Emmanuel Guilmeau, Karel Knížek
Materials Science · Cross-listed from cond-mat.mes-hall
Topology as a Design Variable for Multiproperty Engineering in Synthesized 4-5-6-8 Carbon Nanoribbons
Djardiel da S. Gomes, Isaac M. Felix, Lucas L. Lage et al. (+3 more)
Nonbenzenoid carbon frameworks expand low-dimensional material design via controlled asymmetry. Here, we show the experimentally realized 4-5-6-8 carbon nanoribbon establishes a
topology-driven paradigm for multiproperty engineering, not just a
graphene variant. Using hybrid DFT, tight-binding, and molecular dynamics in a multiscale framework, we demonstrate the
symmetry-broken
lattice stabilizes hierarchical bonds within standard energy ranges. This geometry produces a robust semiconducting state (hybrid gap >1 eV) and enables strain as a controllable modulation parameter. A tight-binding
Hamiltonian fitted only at
equilibrium accurately captures strain-dependent band
evolution, proving the essential physics is
topology-dominated. Mechanical analysis reveals high stiffness with fracture governed by the largest polygons, showing asymmetry redistributes stress without compromising integrity. Intrinsic
phonon scattering suppresses thermal conductance, enabling favorable thermoelectric performance without extrinsic disorder. Optical response confirms non-equivalent ring connectivity reorganizes interband transitions, promoting strong visible absorption and efficient photocarrier generation. These results position
topology as a governing parameter coupling elasticity, electronics, thermal transport, and optics, establishing the 4-5-6-8 nanoribbon as a unified platform for predictive design of multifunctional carbon materials.
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All authors Djardiel da S. Gomes, Isaac M. Felix, Lucas L. Lage, Douglas S. Galvão, Andrea Latgé, Marcelo L. Pereira Junior
Materials Science
Interfacial properties of MoS2 thin films grown on functional substrates
Hafiz Sami Ur Rehman, Nunzia Coppola, Alice Galdi et al. (+8 more)
Interface chemistry and defect formation in MoS2 thin films grown on single
crystal substrates critically determine the electronic structure of MoS2 and thus can strongly modify material functionality relevant for many applications, including electronics, optoelectronics, and energy related catalysis. We investigate MoS2 grown on three technologically relevant substrates, namely SrTiO3(111), c-axis Al2O3(0001) and 6H-SiC(0001). Experimental investigations by temperature dependent resistivity, photoemission spectroscopy and scanning transmission electron microscopy with coupled energy dispersive spectroscopy, with the support of theoretical calculation by Density Functional Theory, allow the identification of the substrate induced specific defects and their correlation with the electronic properties. Ti interdiffusion in SrTiO3/MoS2 generates donor like states near the
Fermi level, leading to metallic transport. Al2O3/MoS2 exhibits a high density of sulfur related defects that introduce localized states and yield nearly temperature independent conductivity. SiC/MoS2 exhibits significant interface disorder resulting in a semiconducting temperature dependent resistivity, yet deviating from the ideal bulk like behavior. These results demonstrate how substrate choice governs defect formation and ultimately dominates the electronic behavior of MoS2 thin films, making the control of film substrate interactions essential for the engineering of new functional devices.
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All authors Hafiz Sami Ur Rehman, Nunzia Coppola, Alice Galdi, Sandeep Kumar Chaluvadi, Shyni Punathum Chalil, Pasquale Orgiani, Sara Passuti, Regina Ciancio, Paolo Barone, Luigi Maritato, Carmela Aruta
Materials Science · Cross-listed from cond-mat.str-el
Conductivity scaling of the anomalous Hall effect in the altermagnetic semiconductor {\alpha}-MnTe
Sara Bey, Shelby S. Fields, Nicholas G. Combs et al. (+22 more)
{\alpha}-MnTe is a prototypical altermagnet exhibiting a strong anomalous
Hall effect (AHE), despite having a nearly vanishing magnetization. Lately, sample-to-sample variations of the amplitude of the AHE have raised concerns of a possible defect related origin, especially in thin films. Here, we study the AHE in {\alpha}-MnTe films grown on SrF2 that have the
crystal structure and m'm'm
magnetic point group
symmetry expected for bulk. By studying the scaling of the AHE with conductivity for those films and previously reported measurements in the literature, we find that sample-to-sample variations are well explained by a scaling law consistent with a hopping origin. Importantly, a comparison with other
magnetic semiconductors reveals the colossal amplitude of the AHE of {\alpha}-MnTe compared to its measured spontaneous magnetization from magnetometry and polarized
neutron reflectivity. Our findings address the important fundamental question of the origin of the AHE of {\alpha}-MnTe and further demonstrate the potential of altermagnets as promising spintronic materials.
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All authors Sara Bey, Shelby S. Fields, Nicholas G. Combs, Bence G. Márkus, Jiashu Wang, Liam Schmidt, Lincoln Curtis, Allecia Dodd-Noble, Alexander Poulin, Syed Mohammad Shahed, Resham Regmi, Mariia Holub, Phillipe Ohresser, Arun Bansil, Swastik Kar, Haile Ambaye, Valeria Lauter, László Forró, Cory D. Cress, Joseph C. Prestigiacomo, Nirmal Ghimire, Alberto de la Torre, Steven P. Bennett, Xinyu Liu, Badih A. Assaf
Materials Science
Resolving the Metastable Si-XIII Structure through Convergent Theory and Experiment
Fabrizio Rovaris, Corrado Bongiorno, Anna Marzegalli et al. (+10 more)
Silicon is the undisputed cornerstone of modern technology, with applications ranging from micro- and opto-electronics to
quantum technologies. Recently, the exploration of its allotropes has emerged as a pivotal frontier for engineering materials with tailored optical and electronic functionalities. High-pressure experiments have revealed several metastable silicon phases, among which is Si-XIII. First observed more than 20 years ago, this phase has remained structurally unidentified, representing a significant gap in our understanding of elemental silicon allotropy. In this work, a convergent methodology is employed combining advanced theoretical modeling with experimental characterization to finally resolve the long-standing structural assignment of Si-XIII. Guided by careful experimental observations, a structural model validated through first-principles optimization and systematically tested against multiple experimental signatures is constructed. All the fingerprints of this phase are rationalized by our proposed
crystal structure: interplanar spacings, Raman frequencies, thermodynamic stability, and kinetic pathways. These findings provide a crucial missing piece in the high-pressure phase diagram of silicon and demonstrate the power of integrating computational predictions with experimental validation to resolve complex structural problems in materials science.
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All authors Fabrizio Rovaris, Corrado Bongiorno, Anna Marzegalli, Mouad Bikerouin, Davide Spirito, Gerald J. K. Schaffar, Mohamed Zaghloul, Agnieszka Anna Corley-Wiciak, Francesco Montalenti, Verena Maier-Kiener, Giovanni Capellini, Antonio M. Mio, Emilio Scalise
Materials Science
Mechanism-Resolved PFM of Ferroionic and Ferroelectric Responses in Thickness-Gradient Hf0.5Zr0.5O2 Libraries
Yu Liu, Yi-Xiu Chen, Haotong Liang et al. (+2 more)
Resolving growth mechanisms and thickness
evolution of functional properties is one of the key tasks in materials discovery and optimization involving thin-film materials, traditionally requiring significant experimental budgets. Here we introduce the combination of thickness-gradient libraries and automated scanning probe microscopy as a systematic pathway to elucidate growth modes and disentangle ferroelectric and electrochemical contributions in ferroelectric thin films. As a model system, we explore the Hf0.5Zr0.5O2 (HZO) gradient thin films grown on LaxSr1-xMnO3 (LSMO) bottom electrode thin films. Automated piezoresponse force microscopy, spectroscopy, and lithography reveals that irreversible topographic deformation arises from electrochemical activity at the LSMO surface, whereas reversible phase inversion in HZO reflects ferroelectric switching. Automated topography height-map scans are used to further quantify nucleation density, particle-size
evolution, and roughness correlations across the thickness-gradient, demonstrating that improved plume stabilization during growth suppresses interfacial reactions and promotes dense, fine-grained HZO conducive to ferroelectric phase formation. This combined materials-engineering and automated-SPM framework establishes a platform for high-throughput, mechanism-resolved characterization of ferroionic and ferroelectric responses in complex
oxide films.
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All authors Yu Liu, Yi-Xiu Chen, Haotong Liang, Ichiro Takeuchi, Sergei V. Kalinin
Materials Science
Spin dynamics of the spin-1 triangular lattice Heisenberg antiferromagnet K$_2$Ni(SeO$_3$)$_2$
Chaebin Kim, Sathvik Nallapati, E. A. Ghioldi et al. (+6 more)
Strong
quantum fluctuations and unconventional
spin dynamics are well established in the
spin-1/2 triangular
lattice Heisenberg antiferromagnet. However, their survival in the
spin-1 case remains an open question. We investigate the
spin dynamics of K$_2$Ni(SeO$_3$)$_2$, a nearly ideal
spin-1 triangular
lattice Heisenberg antiferromagnet, using inelastic
neutron scattering. Below the ordering temperature $T_{\rm N}$, we observe coherent one-
magnon excitations coexisting with a broad high-energy continuum. Two complementary approaches, a spectrally consistent $1/S$-corrected
spin wave theory and a beyond-mean-field Schwinger
boson theory, reproduce different facets of the continuum. Neither alone is complete, demonstrating substantial
quantum fluctuations survive for $S\!=\!1$ and are reflected primarily in the spectral distribution of the continuum. Above $T_{\rm N}$, the continuum bandwidth is conserved while spectral weight is redistributed as
magnons lose spatial coherence. Our results establish K$_2$Ni(SeO$_3$)$_2$ as a model triangular antiferromagnet, identifying bandwidth conservation and the distribution of spectral weight within the continuum as organizing principles to understand the
spin dynamics of ordered
quantum magnets beyond
spin-1/2. Our results highlight the need for controlled calculations of the interacting multi-
magnon sector of 2D antiferromagnets.
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All authors Chaebin Kim, Sathvik Nallapati, E. A. Ghioldi, Long Chen, Alexander I. Kolesnikov, Haidong Zhou, Shang-Shun Zhang, Cristian D. Batista, Martin Mourigal
Materials Science
Dirac semimetal phases in chiral carbon nanoscrolls
Tzu-Ching Hsu, Jhih-Shih You, Hsiu-Chuan Hsu et al. (+1 more)
Chirality induced by rolling a two-dimensional material into a spiral geometry reshapes its electronic band structure. In this work, we theoretically investigate the topological properties of carbon nanoscrolls under an axial
magnetic field, focusing on structures in which chirality is encoded through shifted edge
alignments. In contrast to unshifted structures, where mirror
symmetry pins the Dirac cones to half a flux
quantum,
chiral carbon nanoscrolls lack this
symmetry, and Dirac cones emerge at
magnetic flux values away from half a flux
quantum. We demonstrate that these Dirac cones are topologically protected by combined inversion-time reversal
symmetry and remain robust even when sublattice
symmetry is broken. Furthermore, we show that the number of Dirac cones and their real-space probability distributions depend on the number of turns and the
magnetic field strength. Our study elucidates the role of chirality in the band
topology of nanoscroll geometries.
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All authors Tzu-Ching Hsu, Jhih-Shih You, Hsiu-Chuan Hsu, Ion Cosma Fulga
Materials Science · Cross-listed from cond-mat.str-el
Spontaneous Fully Compensated Ferrimagnetism
Bingbing Wang, Yongpan Li, Yichen Liu et al. (+1 more)
We propose a general mechanism for the spontaneous emergence of filling-enforced fully compensated ferrimagnetism (fFIM), characterized by zero net magnetization yet
ferromagnetic-like
spin-split band structures. Using Hartree-Fock mean-field calculations of the Hubbard model, we map out the stability regime of spontaneous fFIM over a broad parameter space of interaction strength and staggered potential. We show the unique
quantum-geometry-governed optical selection rules and the abundant valley- and
spin-related physics of electronics and optics arising from the emergence of fFIM order, with tunable
spin-polarized and valley-contrasting charge and
spin currents. Furthermore, based on our theory, we demonstrate that spontaneous fFIM can be realized in nominally nonmagnetic
graphene via defect engineering. Our results establish a unified framework for the mechanism, emergent properties, and materials realization of spontaneous fFIM, opening new opportunities for spintronic, valleytronic, and optoelectronic applications.
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All authors Bingbing Wang, Yongpan Li, Yichen Liu, Cheng-Cheng Liu
Materials Science
Synthesis and Structural Analysis of an Emissive Colloidal Argyrodite Nanocrystal: Canfieldite Ag8SnS6
Francisco Yarur Villanueva, Victor Quezada Novoa, Pascal Rusch et al. (+12 more)
We resolve a phase identification controversy in the Ag-Sn-S material system by unraveling the polymorphic structure of nanocrystals within the argyrodite material family. Argyrodites are a class of superionic materials used in their bulk form for applications in solid-state batteries and thermoelectrics, where their advantageous properties relate to their polymorphism. However, despite their well-studied bulk applications, the limited exploration at the nanoscale has left considerable potential for the discovery of emerging properties due to size effects. Further, phase identification presents a prominent challenge to the study of polymorphs in superionic conductors and related mate-rials. In this work, we synthesize canfieldite-like (Ag8SnS6) nanocrystals to understand their formation and structural behavior at the nanoscale. We observe the emergence of emissive, meta-stable, cluster-like species. Then, high-resolution transmission electron microscopy reveals indistinguishable polymorphs of canfieldite due to identical heavy-atom frameworks. However, using synchrotron X-ray total scattering for pair distribution function analysis, we uncover structural distortions, showing a pseudo-orthorhombic configuration that likely gives rise to the red emission. Further, we investigate the optical properties and structure of Ag8SnS6 nanocrystals upon the addition of Zn2+, the cation of interest in the canfieldite vs. pirquitasite (Ag2ZnSnS4) phase identification controversy. We show that Zn2+ is incorporated in the canfieldite-like structure through the replacement of Ag+, boosting the emission. Our results solve a standing phase identification challenge and uncover fundamental insights for the synthesis and structure of canfieldite nanocrystals, laying the ground for the exploration of other argyrodite materials with emerging properties at the nanoscale.
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All authors Francisco Yarur Villanueva, Victor Quezada Novoa, Pascal Rusch, Stefano Toso, Maxwell W. Terban, Yurii P. Ivanov, Joaquin Carlos Chu, Maxine J. Kirshenbaum, Ehsan Nikbin, Maria J. Gendron Romero, Mirko Prato, Giorgio Divitini, Jane Y. Howe, Mark W.B. Wilson, Liberato Manna
Materials Science · Cross-listed from physics.optics
All-optical control of second-harmonic generation in $\beta$-BaB$_2$O$_4$ via coherent, terahertz-driven acentric lattice displacement
Flavio Giorgianni, Nicola Colonna, Gabriel Nagamine et al. (+6 more)
Dynamical control of the nonlinear optical properties of solids – with light itself – will be essential for future ultrafast photonic technologies. Previously, methods to modulate nonlinear processes including second-harmonic generation (SHG) have relied primarily on non-resonant light-matter interaction or photo-generation of hot electrons in nanoscale materials. However, these approaches are typically constrained by limited interaction lengths and the initial frequency conversion is relatively weak under
equilibrium conditions. Here, an approximately 30% modulation of efficient phase-matched SHG in bulk beta-barium borate (beta-BaB2O4) is achieved through transient
lattice deformation by intense terahertz (THz) pulses that are tuned to resonance with an infrared-active
phonon mode. The effect originates from modification of the index of refraction ellipsiod and the corresponding nonlinear phase-matching conditions, rather than from direct modulation of the nonlinear susceptibility through THz-mediated chi^(3) processes. This mechanism, of resonant selective
lattice excitation, points toward novel THz-control schemes to tune the nonlinear optical response in materials.
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All authors Flavio Giorgianni, Nicola Colonna, Gabriel Nagamine, Leonie Spitz, Guy Matmon, Alexandre Trisorio, Nicolas Forget, Carlo Vicario, Adrian L. Cavalieri
Materials Science
Interfacial Oxidation Enables Charge-Transfer Contacts and Degenerate n-Doping in Monolayer MoS$_2$
Marco Bianchi, Daniel Lizzit, Alberto Turoldo et al. (+7 more)
High contact resistance remains a central obstacle to the integration of two-dimensional (2D)
semiconductors in electronic devices. Recent advances have demonstrated that contact performance can be dramatically improved through interface engineering, including the use of group-V semimetals and charge-transfer contacts based on strong interfacial doping. Here, we show that controlled interfacial oxidation provides an effective route to convert a semimetal contact into a charge-transfer contact that degenerately $n$-dopes single layer MoS$_2$. Using a combination of angle-resolved photoemission spectroscopy, X-ray photoelectron diffraction, low-energy electron diffraction and scanning tunnelling spectroscopy, we demonstrate that putting single layer MoS$_2$ in contact with a pristine Bi layer merely results in weak doping, whereas oxidation of the Bi layer leads to a pronounced occupation of the MoS$_2$ conduction band with an electron density on the order of $10^{13}$~cm$^{-2}$. The cause of this strong electron doping is the fact that an ultrathin $\beta$-Bi$_2$O$_3$ layer forms below the MoS$_2$ and that this has a particularly low work function, thereby acting as an efficient electron donor to MoS$_2$. Interfacial oxidation thus emerges as a powerful design knob for engineering charge-transfer contacts to 2D
semiconductors.
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All authors Marco Bianchi, Daniel Lizzit, Alberto Turoldo, Ezequiel Tosi, Paolo Lacovig, Monika Schied, Davide Curcio, Charlotte E. Sanders, Silvano Lizzit, Philip Hofmann
Materials Science · Cross-listed from cond-mat.mes-hall
Nanoelectronics with Two Dimensional Magnets
Bing Zhao, Roselle Ngaloy, Lalit Pandey et al. (+3 more)
Two dimensional (2D) magnets have emerged as a compelling platform for
spin based nanoelectronics, enabling atomic scale control of
magnetic order, interfaces,
quantum geometry, and
symmetry. Here, we highlight recent advances in 2D ferromagnets, antiferromagnets, altermagnets, and related
magnetic phases, emphasizing how enhanced Curie temperatures, perpendicular
magnetic anisotropy, and unconventional
magnetic orders translate into device relevant functionality.
Spin dependent transport in vertical
magnetic tunnel junctions and lateral
spin valves based on 2D
heterostructures are discussed, where atomically sharp interfaces enable highly tunable
spin injection, propagation, and detection. We further focused on field free energy efficient
spin orbit torque magnetization switching in 2D
magnetic heterostructures, in which unconventional
spin currents originate from an adjacent low
symmetry spin orbit layer. Microscopic mechanisms involving
symmetry breaking, Berry
curvature, and orbital angular momentum transport are discussed, along with key challenges, including switching determinism and torque efficiency. Materials and device design strategies targeting neuromorphic, hybrid
quantum spintronic, and multifunctional architectures are outlined. Collectively, these developments position 2D magnets as a promising candidate for tunable, energy efficient integrated spintronic technologies that can harness intertwined
spin, charge, orbital, and topological degrees of freedom at the nanoscale.
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All authors Bing Zhao, Roselle Ngaloy, Lalit Pandey, Himanshu Bangar, Divya P. Dubey, Saroj P. Dash
Materials Science
Fermi-surface studies of altermagnetic CrSb from Shubnikov-de Haas oscillations
Sajal Naduvile Thadathil, Beat Valentin Schwarze, Jaafar Ansari et al. (+14 more)
Within the family of altermagnets, CrSb is a metallic, collinearly ordered material that exhibits particularly strong
symmetry-induced
spin splitting in its band structure. In this study, we combine electrical magnetotransport measurements up to 68 T on microfabricated single-crystalline CrSb with first-principles calculations to investigate its
Fermi surface. Notably, we study the temperature and field-orientation dependence of
magnetic quantum oscillations observed in the magnetoresistance. The observed frequency spectrum agrees well with results from density-functional-theory calculations. Our results confirm the predicted electronic band structure of altermagnetic CrSb and highlight the importance of high
magnetic fields for accurately mapping the
Fermi surfaces of unconventional emergent materials.
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All authors Sajal Naduvile Thadathil, Beat Valentin Schwarze, Jaafar Ansari, Tommy Kotte, Sven Luther, Marc Uhlarz, Freya Husstedt, Rafael Gonzalez-Hernandez, Libor Šmejkal, Thanassis Speliotis, Markéta Žáčková, Jiří Pospíšil, Christoph Müller, Dominik Kriegner, Helena Reichlová, Joachim Wosnitza, Toni Helm
Materials Science · Cross-listed from cond-mat.supr-con
Superconductivity in the A15-type V3(Os1-2xSixGex) medium-entropy alloys
Yucheng Li, Kuan Li, Lingyong Zeng et al. (+4 more)
Cubic A15-type superconducting
alloys continue to fascinate the academic and industrial fields because they mainly support the largest
market for low-temperature superconducting applications and show exotic physical properties. Medium-/high-
entropy alloys (MEAs-HEAs) can be employed stably under extreme conditions due to their high mechanical hardness and excellent irradiation tolerance. Combining with the features of the A15-type
superconductor and MEAs-HEAs, we design a series of previously unreported A15-type V3(Os1-2xSixGex) (x = 0.333, 0.375, 0.425) MEA
superconductors, which can be obtained by an arc melting method. Resistivity,
magnetic susceptibility, and specific heat measurements indicate that all of them are type-II bulk
superconductors. The superconducting transition temperature (Tc) exhibits an upward trend with the systematic reduction of Os concentration. Additionally, the upper critical field of the V3(Os0.333Si0.333Ge0.333) sample is larger than the Pauli limit, suggesting it may be robust against
magnetic fields due to
spin-orbit coupling induced by the heavy Os atoms. These findings not only advance our understanding of emergent phenomena in
entropy-stabilized A15-type
alloys but also expand the members of new
superconductors.
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All authors Yucheng Li, Kuan Li, Lingyong Zeng, Rui Chen, Jingjun Qin, Shuangyue Wang, Huixia Luo
Materials Science · Cross-listed from cond-mat.soft
Activity-Driven Dewetting and Rupture in Thin Liquid Films
Preethi M, Daniya Davis and Bhaskar Sen Gupta
Thin-film dewetting is classically governed by an adhesion-mediated spinodal instability in which
curvature-driven
diffusion controls post-rupture coarsening. We show that internal activity fundamentally restructures this instability. Using a minimal microscopic model of an active
liquid film on a solid substrate, we identify a competition between active stresses and film-substrate adhesion that produces two independently regulated dynamical length scales: vertical
liquid accumulation and lateral rupture propagation. While passive films exhibit universal
diffusion-limited growth, $\ell_z(t)\sim t^{1/3}$, activity converts transport from
curvature-controlled
diffusion to persistence-driven motion, yielding a continuous increase of the coarsening exponent from $\approx 0.33$ to $\approx 0.6$. The growth law analysis shows that persistent self-propulsion introduces an advective flux that competes with
curvature-induced chemical potential gradients, enhancing growth when the persistence length becomes comparable to the evolving domain size. Simultaneously, the rupture front transitions from dissipative spreading to strongly accelerated propagation approaching ballistic scaling. This decoupling shows that activity does not simply renormalize effective surface forces but generates a distinct nonequilibrium interfacial instability governed by the balance between persistence length and adhesion. The results provide a minimal physical mechanism linking classical thin-film dewetting to dewetting-like rupture observed in active and biological materials.
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Materials Science · Cross-listed from cond-mat.str-el
Phonon-Assisted Photoluminescence and Ultrafast Exciton Dynamics in Two-Dimensional Silicon Carbide
Afreen Anamul Haque, Rishabh Saraswat, Aniket Singha et al. (+2 more)
Phonon assisted photoluminescence provides a direct window into
exciton phonon interactions in
semiconductors. Using fully ab initio many-body perturbation theory, including finite momentum Bethe Salpeter calculations, we investigate
phonon-assisted emission and
exciton dynamics in two dimensional (2D) hexagonal silicon carbide (hSiC) and
benchmark its response against 2D h boron nitride (hBN). By explicitly resolving
exciton phonon matrix elements, we identify an electron-
phonon scattering channel mediated by A$^\prime$ high energy longitudinal and transverse optical
phonons as the dominant contributors to sideband formation and quantify their spectral weights. We find that h SiC exhibits pronounced
phonon-assisted sidebands comparable to hBN, despite a smaller
exciton phonon energy separation and fewer resolved replicas. The bright KK
exciton governs near UV zero
phonon emission, while intervalley
excitons acquire radiative character through
symmetry allowed optical
phonon coupling. Temperature dependent scattering rates reveal an ultrashort bright
exciton lifetime of approximately 300 fs at 10 K, highlighting rapid
exciton relaxation driven by intrinsic
phonon channels.
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All authors Afreen Anamul Haque, Rishabh Saraswat, Aniket Singha, Rekha Verma, Sitangshu Bhattacharya
Materials Science · Cross-listed from cond-mat.soft
Thermodynamic effects of solid electrolyte interphase formation from solvation and ionic association in water-in-salt electrolytes
Daniel M. Markiewitz, Michael McEldrew, Conor M. E. Phelan et al. (+6 more)
Water-in-Salt-Electrolytes (WiSEs) are a promising class of next-generation electrolytes. Unlike classical dilute electrolytes or more conventional battery electrolytes, WiSEs are characterised by their super-concentrated salt concentration with only a small amount of water, which gives rise to their expanded electrochemical stability window (ESW). The expansion of the ESW is, in part, due to the formation of an inorganic solid electrolyte interphase (SEI) that passivates the anode; this principle is also important in graphite and Li-metal anodes, and beyond Li-ion technologies. The solvation and ionic associations are key descriptors in understanding the expansion of the ESW. Specifically, as reactions which lead to the SEI (or cathode electrolyte interphase, CEI) must occur at the electrode-electrolyte interface, the distribution of reactants and their various solvation environments are critical. This distribution near the interface is referred to as the electrical double layer (EDL), in the absence of reactions. Here we further develop and analyse a recently proposed thermodynamic theory of hydration and ionic associations in the EDL of WiSEs. We parameterize this theory from bulk molecular dynamics simulations and
benchmark it against EDL simulations, finding good qualitative agreement. Using this thermodynamic theory, we rationalise changes in the ESW through: changes in the activity in the bulk electrolyte through the Nernst equation, which directly changes the stability of the electrolytes; and thermodynamic changes to the kinetics of these reactions, from the Butler-Volmer equation and coupled ion electron transfer kinetics, through the concentration of reactant species in the Helmholtz layer.
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All authors Daniel M. Markiewitz, Michael McEldrew, Conor M. E. Phelan, Qianlu Zheng, Jasper Singh, Robert S. Weatherup, Rosa M. Espinosa-Marzal, Martin Z. Bazant, Zachary A. H. Goodwin
Materials Science
A Nanocrystal Synthesis Derived Approach to Silver Bismuth Iodide Layered Double Perovskites with Aliphatic Amines: (CnH(2n+1)NH3)4AgBiI8
Pascal Rusch, Ann Mary Antony, Meenakshi Pegu et al. (+9 more)
Lead-free iodide double perovskites are an interesting class of materials since they combine a relatively low toxicity (compared to the lead counterpart) with the small bandgap typical of iodide-based perovskite structures. Their reported number is small due to their lower structural stability compared to the chloride and bromide analogues, hence their difficult synthesis. The structural constraints that limit stability, on the other hand, can be much relieved in layered, organic-inorganic perovskites. Following this line of thought, we report here a successful fast precipitation route to iodide layered (CnH(2n+1)NH3)4AgBiI8 (n = 10, 12, and 14) double perovskites that borrow concepts from the synthesis of colloidal nanocrystals. X-ray diffraction studies revealed for these compounds a monoclinic
crystal structure containing edge-sharing alternated [AgI6] and [BiI6] octahedra. These materials have experimental band gaps of 2.1 eV, as also corroborated by theoretical calculations. We have also investigated their phase transitions by thermal analysis and temperature-dependent diffraction and found them to be similar to their lead-based layered perovskite counterparts.
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All authors Pascal Rusch, Ann Mary Antony, Meenakshi Pegu, Meysoun Jabrane, Gabriele Saleh, Arghyadeep Garai, Aswin Asaithambi, Simone Lauciello, Sergio Marras, Serena De Negri, Pavlo Solokha, Liberato Manna
Materials Science · Cross-listed from cond-mat.supr-con
Reply to "Threefold error in the reported zero-field cooled magnetic moment of single crystal $La_2SmNi_2O_7$ (arXiv: 2602.23240)"
Feiyu Li, Zhenfang Xing, Di Peng et al. (+24 more)
We respond to the critique by Aleksandr V. Korolev and Evgeny F. Talantsev on the superconducting phase fraction ($f$) calculations in Li et al. Nature 649, 871-878 (2026). First, the weak upturn in the low-temperature tail of our data has been confirmed to originate from the background, and the paramagnetic Meissner effect is absent in our case; thus, field-cooled (FC) data can be used for superconducting phase fraction calculations. Second, demagnetization effect must be calculated based on the actual measured moment as a function of $f$, which has been well-established and routinely employed in the superconductivity community. In contrast, Korolev and Talantsev treated the demagnetization field as a constant; thus, their calculation underestimates $f$ by a factor of $(1-N\chi_{meas})(1-N)$. This factor is close to 1/3, given $N$ = 0.849, $\chi_{meas}$ = -1.313 in our study, which explains the origin of their deviated result (nearly three times smaller than our results). Third, our sample is a homogeneous high-quality bulk single
crystal, evidenced by various techniques, making the existence of multiple discrete superconducting regions highly unlikely. We conclude that the superconducting phase fraction calculations reported in Li et al. Nature 649, 871-878 (2026) are not invalidated by the analyses presented in Korolev et al. arXiv: 2602.23240 (2026).
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All authors Feiyu Li, Zhenfang Xing, Di Peng, Jie Dou, Ning Guo, Liang Ma, Yulin Zhang, Lingzhen Wang, Jun Luo, Jie Yang, Jian Zhang, Tieyan Chang, Yu-Sheng Chen, Weizhao Cai, Jinguang Cheng, Yuzhu Wang, Yuxin Liu, Tao Luo, Naohisa Hirao, Takahiro Matsuoka, Hirokazu Kadobayashi, Zhidan Zeng, Qiang Zheng, Rui Zhou, Qiaoshi Zeng, Xutang Tao, Junjie Zhang
Materials Science
Structural Evolution during Reversible Halogen Intercalation into WTe2: Commensurate-Incommensurate WTe2I and Multistage WTe2Brx (x = 0.5, 1.0 and 1.25)
Patrick Schmidt, Carl P. Romao and Hans-Jürgen Meyer
Halogen intercalation into the layered material tungsten ditelluride (WTe2) provides a unique pathway to tune its structural and electronic properties. In this study, we detail the synthesis and characterization of the new bromine-intercalated phases WTe2Brx (x = 0.5, 1.0, and 1.25), and reinvestigate the iodine-intercalated analogue, WTe2I. A defining feature of the bromine system is its rapid and reversible "breathing" behavior at room temperature, allowing guest molecules to be absorbed or released from the van der Waals gaps under ambient conditions. Structural analysis shows that the bromine-poor phase WTe2Br0.5 crystallizes in the orthorhombic space group Pmmn, thereby maintaining a uniform stacking sequence. In contrast, the bromine-rich WTe2Br1.25 phase (space group Imm2) adopts an architecture where two distinct types of bromine layers alternate between the host layers. For the iodine system, the compound WTe2I exhibits both incommensurate and commensurate (3+1)D modulated variants in the superspace group P21/m({\alpha}0{\gamma})00. In the commensurate polytype, the structural modulation locks into a rational vector, q = (1/2, 0, 1/6), which can be described also as a 3D supercell. Electronic structure calculations show WTe2Br0.5 and commensurately modulated WTe2I to be metals with flat bands at the
Fermi energy arising from the intercalation. These findings demonstrate the unusual stability and structural flexibility of anionic intercalation in a transition metal dichalcogenides.
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Materials Science
kALDo 2.0: Scalable Thermal Transport from First Principles and Machine Learning Potentials
Giuseppe Barbalinardo, Zekun Chen, Dylan Folkner et al. (+5 more)
We introduce kALDo2.0, an open-source Python package for computing vibrational, elastic, and thermal transport properties of solids from first principles and machine-learned interatomic potentials. Building on the anharmonic
lattice dynamics (ALD) framework, kALDo2.0 provides efficient CPU and GPU-accelerated implementations of the Boltzmann transport equation (BTE) for
crystals and the quasi-harmonic Green-Kubo (QHGK) method. QHGK extends thermal transport predictions beyond
crystals to disordered materials, including glasses,
alloys, and complex nanostructures. kALDo2.0 introduces native integration with modern machine-learned potentials (MLPs), enabling thermal transport workflows that combine the accuracy of first-principles methods with the scalability of classical force fields. It also features comprehensive support for temperature-dependent effective potentials workflows, flexible storage backends for large-scale calculations, and advanced quantification of anharmonicity. The software seamlessly interfaces with electronic structure codes (
Quantum ESPRESSO, VASP), molecular dynamics packages (LAMMPS), and MLPs (ACE, NEP, MACE, MatterSim, Orb), enabling thermal transport studies from 0 K to finite temperatures. kALDo2.0 implements multiple BTE solution strategies and essential physical corrections, including isotopic scattering and non-analytical terms for polar materials. A modular Python architecture with lazy evaluation and multiple storage formats (ASCII, NumPy, HDF5) enables simulations of systems containing up to tens of thousands of atoms. This paper describes the theoretical framework, implementation details, software architecture, and validation examples demonstrating kALDo2.0's capabilities for studying complex materials, including halide perovskites with strong anharmonicity and polar
oxides requiring long-range electrostatic corrections.
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All authors Giuseppe Barbalinardo, Zekun Chen, Dylan Folkner, Bohan Li, Nicholas W. Lundgren, Nathaniel Troup, Alfredo Fiorentino, Davide Donadio
Materials Science
Equilibrium kink-like torsion deformation of a magnetoactive elastomer under a magnetic field
Yu. I. Dzhezherya, A. V. Kyryliuk, S. V. Cherepov et al. (+4 more)
A novel effect involving the formation of a stable kink-like torsion deformation in a magnetoactive elastomer (MAE) beam subjected to a uniform
magnetic field is theoretically predicted and experimentally confirmed. The phenomenon was demonstrated using an elastomer beam containing soft
magnetic carbonyl iron microparticles within a silicone
matrix. The torsion kink acts as a transition boundary between two undeformed homogeneous states of the beam. We show that the elastic moment is compensated by a magnetoelastic moment in the kink region, where the local magnetization of the beam is non-collinear to the applied
magnetic field due to shape anisotropy. It is established that within the kink region, the MAE beam exists in a non-uniformly elastically deformed, low-
symmetry magnetic state. Outside the kink, the beam's magnetization is collinear with the
magnetic field, corresponding to an undeformed, high-
symmetry homogeneous
magnetic state.
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All authors Yu. I. Dzhezherya, A. V. Kyryliuk, S. V. Cherepov, Yu. B. Skirta, S. O. Reshetniak, S. M. Ryabchenko, V. M. Kalita
Materials Science · Cross-listed from cond-mat.supr-con
Intrinsic translational symmetry-breaking charge stripes in underdoped iron pnictides
Qiang-Jun Cheng, Cong-Cong Lou, Yong-Wei Wang et al. (+4 more)
Despite being well established in cuprates, an intrinsic translational
symmetry-breaking charge order has not been clearly identified in iron-based
superconductors. Using spectroscopic-imaging scanning tunneling microscopy on epitaxial Ca(Fe1-xCox)2As2 (x = 0 ~ 0.055) thin films, we observe smectic, near-commensurate charge-stripe order in the underdoped regime that intervenes between the nematic parent phase and optimally doped superconductivity. Distinct from the bidirectional checkerboard-like order in cuprates, these charge stripes are unidirectional along the
antiferromagnetic Fe-Fe bond direction and are accompanied by a van Hove singularity near the
Fermi level, inherited from the
Fermi surface reconstruction driven by intertwined
antiferromagnetic and nematic correlations. Both local and global suppression of the charge-stripe instability enhance superconductivity, tunable via epitaxial strain and Co doping. These results establish charge-stripe order as an intermediate electronic phase in iron pnictides and reveal a coherent pathway from nematicity to superconductivity. Our findings highlight charge ordering as a unifying element across different families of high-temperature
superconductors.
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All authors Qiang-Jun Cheng, Cong-Cong Lou, Yong-Wei Wang, Ze-Xian Deng, Xu-Cun Ma, Qi-Kun Xue, Can-Li Song
Materials Science
High sub-bandgap response and fast switching enabled by thermal quenching in carbon-doped semi-insulating GaN
Jiahao Dong, Auditee Majumder Momo, Austin Fehr et al. (+6 more)
Carbon-doped GaN is a promising material for sub-bandgap triggered optical switches. When incorporated in GaN, carbon introduces deep compensating centers that enable defect-mediated extrinsic photoconductivity. Here, we investigate the optical responsivity and switching kinetics of semi-insulating carbon-doped GaN actuated by sub-bandgap blue illumination. A high ON/OFF ratio exceeding $\mathrm{10^7}$ is achieved under low-irradiance 405-nm excitation. Temperature-dependent transient measurements reveal that the photocurrent decay is thermally quenched above a crossover temperature of ~300 K. This behavior is attributed to hole-emission-assisted recombination. The extracted activation energies vary across samples; a commonly observed value of ~0.83 eV is attributed to the $\mathrm{C_N}$ defect. Notably, when heating above the crossover temperature, thermal quenching accelerates the photocurrent decay by up to a factor of five, enabling significantly faster switching.
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All authors Jiahao Dong, Auditee Majumder Momo, Austin Fehr, Sanam SaeidNahaei, Pramod Reddy, Ronny Kirste, Zlatko Sitar, Ramón Collazo, Selim Elhadj
Materials Science
Ab initio electronic conductivity of Fe-bearing post-perovskite
Yihang Peng, Yupei Zhang, Shuai Zhang et al. (+5 more)
The electrical conductivity of high-pressure silicates profoundly influences the interior dynamics of rocky
planets. Employing the Kubo-Greenwood formalism, we perform ab initio calculations of electronic conductivity in Fe-bearing post-perovskite under super-Earth mantle conditions, up to 4000 K and 500 GPa. Electronic structures are obtained via many-body perturbation theory, incorporating dynamical screening and correlations among localized Fe-3d orbitals. In contrast to (Fe,Mg)O, for which metallization has been reported at comparable conditions, our results indicate that post-perovskite with Earth-like Fe contents is unlikely to metallize in super-Earth mantles via band-gap closure, yielding negligible low-frequency conductivity. Any substantial conductivity would require non-electronic mechanisms, such as thermally activated small-polaron hopping, which fall beyond the scope of band conduction.
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All authors Yihang Peng, Yupei Zhang, Shuai Zhang, Chenxing Luo, Donghao Zheng, Nelson Naveas, Xifan Wu, Jie Deng
Materials Science
Hidden in Plain Sight: Aromaticity of Hexagonal Boron Nitride
Suryakanti Debata, Sai Krishna Narayanan and Pratibha Dev
Hexagonal boron nitride (hBN) and
graphene are similar in many ways - they are isoelectronic, have the same structure, are chemically inert and show persistence. All of these properties are indicators of a deeper connection that has, thus far, been overlooked. Unlike
graphene, which has been shown to be aromatic, it is not known if hBN is aromatic. In this density functional theory-based work, we investigate the aromaticity (or lack thereof ) of hBN. By employing the
magnetic criterion, supported by group theoretic and energetic considerations, we show that hexagonal boron nitride is indeed aromatic, even if weakly so, as compared to
graphene. Since aromaticity is used to understand physical and chemical properties of planar compounds, the picture developed in this work is important to bridging the gap between the physical and chemical understanding of hBN's properties.
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