arXiv - PHYS - Materials Science最新文献

{"title":"Absence of Anomalous Electron-Phonon Coupling in the Temperature Renormalization of the Gap of CsPbBr$_3$ Nanocrystals","authors":"Shima Fasahat, Benedikt Schäfer, Kai Xu, Nadesh Fiuza-Maneiro, Sergio Gómez-Graña, M. Isabel Alonso, Lakshminarayana Polavarapu, Alejandro R. Goñi","doi":"arxiv-2409.06374","DOIUrl":"https://doi.org/arxiv-2409.06374","url":null,"abstract":"Metal halide perovskites exhibit a fairly linear increase of the bandgap with\u0000increasing temperature, when crystallized in a tetragonal or cubic phase. In\u0000general, both thermal expansion and electron-phonon interaction effects\u0000contribute equally to this variation of the gap with temperature. Herein, we\u0000have disentangled both contributions in the case of colloidal CsPbBr$_3$\u0000nanocrystals (NCs) by means of photoluminescence (PL) measurements as a\u0000function of temperature (from 80 K to ambient) and hydrostatic pressure (from\u0000atmospheric to ca. 1 GPa). At around room temperature, CsPbBr$_3$ NCs also show\u0000a linear increase of the bandgap with temperature with a slope similar to that\u0000of the archetypal methylammonium lead iodide (MAPbI$_3$) perovskite. This is\u0000somehow unexpected in view of the recent observations in mixed-cation\u0000Cs$_x$MA$_{1-x}$PbI$_3$ single crystals with low Cs content, for which Cs\u0000incorporation caused a reduction by a factor of two in the temperature slope of\u0000the gap. This effect was ascribed to an anomalous electron-phonon interaction\u0000induced by the coupling with vibrational modes admixed with the Cs\u0000translational dynamics inside the cage voids. Thus, no trace of anomalous\u0000coupling is found in CsPbBr$_3$ NCs. In fact, we show that the linear\u0000temperature renormalization exhibited by the gap of CsPbBr$_3$ NCs is shared\u0000with most metal halide perovskites, due to a common bonding/antibonding and\u0000atomic orbital character of the electronic band-edge states. In this way, we\u0000provide a deeper understanding of the gap temperature dependence in the general\u0000case when the A-site cation dynamics is not involved in the electron-phonon\u0000interaction.","PeriodicalId":501234,"journal":{"name":"arXiv - PHYS - Materials Science","volume":"7 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ferroelasticity in Two-Dimensional Hybrid Ruddlesden$-$Popper Perovskites Mediated by Cross-Plane Intermolecular Coupling and Metastable Funnel-Like Phases","authors":"Devesh R. Kripalani, Qiye Guan, Hejin Yan, Yongqing Cai, Kun Zhou","doi":"arxiv-2409.06333","DOIUrl":"https://doi.org/arxiv-2409.06333","url":null,"abstract":"Ferroelasticity describes a phenomenon in which a material exhibits two or\u0000more equally stable orientation variants and can be switched from one form to\u0000another under an applied stress. Recent works have demonstrated that\u0000two-dimensional layered organic$-$inorganic hybrid Ruddlesden$-$Popper\u0000perovskites can serve as ideal platforms for realizing ferroelasticity,\u0000however, the ferroelastic (FE) behavior of structures with a single octahedra\u0000layer such as (BA)$_2$PbI$_4$ (BA = CH$_3$(CH$_2$)$_3$NH$_3$$^+$) has remained\u0000elusive. Herein, by using a combined first-principles and metadynamics\u0000approach, the FE behavior of (BA)$_2$PbI$_4$ under mechanical and thermal\u0000stresses is uncovered. FE switching is mediated by cross-plane intermolecular\u0000coupling, which could occur through multiple rotational modes, rendering the\u0000formation of FE domains and several metastable paraelastic (PE) phases. Such\u0000metastable phases are akin to wrinkled structures in other layered materials\u0000and can act as a \"funnel\" of hole carriers. Thermal excitation tends to flatten\u0000the kinetic barriers of the transition pathways between orientation variants,\u0000suggesting an enhanced concentration of metastable PE states at high\u0000temperatures, while halogen mixing with Br raises these barriers and conversely\u0000lowers the concentration of PE states. These findings reveal the rich\u0000structural diversity of (BA)$_2$PbI$_4$ domains, which can play a vital role in\u0000enhancing the optoelectronic properties of the perovskite and raise exciting\u0000prospects for mechanical switching, shape memory, and information processing.","PeriodicalId":501234,"journal":{"name":"arXiv - PHYS - Materials Science","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of very slow O diffusion at high temperature on very fast H diffusion in the hydride ion conductor LaH2.75O0.125","authors":"Yoyo Hinuma","doi":"arxiv-2409.05353","DOIUrl":"https://doi.org/arxiv-2409.05353","url":null,"abstract":"Neural network potential based molecular dynamics (MD) simulations on the\u0000excellent H conductor LaH2.75O0.125 show that O starts diffusing above a\u0000critical temperature of Tc~550 K, according to the variance of atom positions\u0000regardless of the time step. The original diffusion process at temperatures\u0000below Tc has an activation barrier of 0.25 eV. Use of MD simulations with\u0000various O and La mass revealed, at above Tc, the coexistence of the 0.25 eV\u0000process and an additional diffusion process with an activation barrier of 0.20\u0000eV. The O and La have strongly anharmonic characters.","PeriodicalId":501234,"journal":{"name":"arXiv - PHYS - Materials Science","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comment on \"Comments regarding \"Transonic dislocation propagation in diamond\" by Katagiri, et al. (Science 382, 69-72, 2023)\" by Hawreliak, et al. (arXiv:2401.04213)","authors":"Kento Katagiri, Tatiana Pikuz, Lichao Fang, Bruno Albertazzi, Shunsuke Egashira, Yuichi Inubushi, Genki Kamimura, Ryosuke Kodama, Michel Koenig, Bernard Kozioziemski, Gooru Masaoka, Kohei Miyanishi, Hirotaka Nakamura, Masato Ota, Gabriel Rigon, Youichi Sakawa, Takayoshi Sano, Frank Schoofs, Zoe J. Smith, Keiichi Sueda, Tadashi Togashi, Tommaso Vinci, Yifan Wang, Makina Yabashi, Toshinori Yabuuchi, Leora E. Dresselhaus-Marais, Norimasa Ozaki","doi":"arxiv-2409.05984","DOIUrl":"https://doi.org/arxiv-2409.05984","url":null,"abstract":"In their comment (1), Hawreliak et al. claims that our observation of\u0000stacking fault formation and transonic dislocation propagation in diamond (2)\u0000is not valid as they interpret the observed features as cracks. In this\u0000response letter, we describe our rationale for interpreting the observed\u0000features as stacking faults. We also address other points raised in their\u0000comments, including the clarifications of how the results of Makarov et al. (3)\u0000are not in conflict with our study.","PeriodicalId":501234,"journal":{"name":"arXiv - PHYS - Materials Science","volume":"60 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the potential of combining over- and under-stoichiometric MIEC materials for Oxygen-Ion Batteries","authors":"Silvère PanissetUniv. Grenoble Alpes, CNRS, Grenoble INP, LMGP, Grenoble, FranceUniv. Grenoble Alpes, CNRS, Grenoble INP, SIMAP, Grenoble, France, Alexander SchmidTU Wien, Institute of Chemical Technologies and Analytics, Vienna, Austria, Alexander StanglUniv. Grenoble Alpes, CNRS, Grenoble INP, LMGP, Grenoble, France, Juergen FleigTU Wien, Institute of Chemical Technologies and Analytics, Vienna, Austria, David JauffresUniv. Grenoble Alpes, CNRS, Grenoble INP, SIMAP, Grenoble, France, Mónica BurrielUniv. Grenoble Alpes, CNRS, Grenoble INP, LMGP, Grenoble, France","doi":"arxiv-2409.05582","DOIUrl":"https://doi.org/arxiv-2409.05582","url":null,"abstract":"The increasing demand for energy storage solutions has spurred intensive\u0000research into next-generation battery technologies. Oxygen-ion batteries\u0000(OIBs), which leverage mixed ionic-electronic conducting (MIEC) oxides, have\u0000emerged as promising candidates due to their solid, non-flammable nature and\u0000potential for high power densities. This study investigates the use of\u0000over-stoichiometric La2NiO4+delta (L2NO4) as a cathode material for OIBs,\u0000exploring its capacity for electrochemical energy storage. Half-cell\u0000measurements reveal that L2NO4 with a closed-pore microstructure can store\u0000oxygen, achieving a volumetric charge of 63 mA.h.cm-3 at 400 {deg}C with a\u0000current density of 3.6 uA.cm-2 and potentials up to 0.75 V vs. 1 bar O2.\u0000Additionally, a functional full cell combining over-stoichiometric L2NO4 and\u0000under-stoichiometric La0.5Sr0.5Cr0.2Mn0.8O3-delta (LSCrMn) has been\u0000successfully developed, demonstrating excellent cyclability and coulomb\u0000efficiency. The full cell reaches a maximum volumetric charge of 90 mA.h.cm-3\u0000at 400 {deg}C, 17.8 uA.cm-2, and a cut-off voltage of 1.8 V. This proof of\u0000concept underscores the viability of combining over- and under-stoichiometric\u0000MIEC materials in OIBs and provides critical insights into optimizing electrode\u0000materials and tuning oxygen content for improved performance. This research\u0000lays the groundwork for future advancements in OIB technology, aiming to\u0000develop materials with lower resistance and higher efficiency.","PeriodicalId":501234,"journal":{"name":"arXiv - PHYS - Materials Science","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tuning the Planarity of an Aromatic Thianthrene-Based Molecule on Au(111)","authors":"Kwan Ho Au-Yeung, Suchetana Sarkar, Sattwick Haldar, Pranjit Das, Tim Kühne, Dmitry A. Ryndyk, Preeti Bhauriyal, Stefan Kaskel, Thomas Heine, Gianaurelio Cuniberti, Andreas Schneemann, Francesca Moresco","doi":"arxiv-2409.05489","DOIUrl":"https://doi.org/arxiv-2409.05489","url":null,"abstract":"Non-planar aromatic molecules are interesting systems for organic electronics\u0000and optoelectronics applications due to their high stability and electronic\u0000properties. By using scanning tunneling microscopy and spectroscopy, we\u0000investigated thianthrene-based molecules adsorbed on Au(111), which are\u0000non-planar in the gas phase and the bulk solid state. Varying the molecular\u0000coverage leads to the formation of two different kinds of self-assembled\u0000structures: close-packed islands and quasi one-dimensional chains. We found\u0000that the molecules are non-planar within the close-packed islands, while the\u0000configuration is planar in the molecular chain and for single adsorbed\u0000molecules. Using vertical tip manipulation to isolate a molecule from the\u0000island, we demonstrate the conversion of a non-planar molecule to its planar\u0000configuration. We discuss the two different geometries and their electronic\u0000properties with the support of density functional theory calculations.","PeriodicalId":501234,"journal":{"name":"arXiv - PHYS - Materials Science","volume":"59 1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regression with Large Language Models for Materials and Molecular Property Prediction","authors":"Ryan Jacobs, Maciej P. Polak, Lane E. Schultz, Hamed Mahdavi, Vasant Honavar, Dane Morgan","doi":"arxiv-2409.06080","DOIUrl":"https://doi.org/arxiv-2409.06080","url":null,"abstract":"We demonstrate the ability of large language models (LLMs) to perform\u0000material and molecular property regression tasks, a significant deviation from\u0000the conventional LLM use case. We benchmark the Large Language Model Meta AI\u0000(LLaMA) 3 on several molecular properties in the QM9 dataset and 24 materials\u0000properties. Only composition-based input strings are used as the model input\u0000and we fine tune on only the generative loss. We broadly find that LLaMA 3,\u0000when fine-tuned using the SMILES representation of molecules, provides useful\u0000regression results which can rival standard materials property prediction\u0000models like random forest or fully connected neural networks on the QM9\u0000dataset. Not surprisingly, LLaMA 3 errors are 5-10x higher than those of the\u0000state-of-the-art models that were trained using far more granular\u0000representation of molecules (e.g., atom types and their coordinates) for the\u0000same task. Interestingly, LLaMA 3 provides improved predictions compared to\u0000GPT-3.5 and GPT-4o. This work highlights the versatility of LLMs, suggesting\u0000that LLM-like generative models can potentially transcend their traditional\u0000applications to tackle complex physical phenomena, thus paving the way for\u0000future research and applications in chemistry, materials science and other\u0000scientific domains.","PeriodicalId":501234,"journal":{"name":"arXiv - PHYS - Materials Science","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural Analysis of Amorphous GeO$_2$ under High Pressure Using Reverse Monte Carlo Simulations","authors":"Kenta Matsutani, Asumi Yamauchi, Shusuke Kasamatsu, Takeshi Usuki","doi":"arxiv-2409.05604","DOIUrl":"https://doi.org/arxiv-2409.05604","url":null,"abstract":"The structural properties of amorphous GeO$_2$, a prototypical network glass,\u0000were investigated under ambient to high pressure using reverse Monte Carlo\u0000simulations based on reported structure factors from in situ high-pressure\u0000neutron diffraction experiments with isotopic substitution. The results\u0000indicate the retention of the topological structure containing predominantly\u0000tetrahedral GeO$_4$ units up to ca.~SI{4}{gigapascal} ($rho/rho_0 =\u00001.15$), which is explained by the reduction of cavity volumes. With further\u0000application of pressure, an increase in the number of GeO$_5$ units is first\u0000observed, which is then followed more gradually by an increase in the number of\u0000GeO$_6$ units.","PeriodicalId":501234,"journal":{"name":"arXiv - PHYS - Materials Science","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142187929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental observation of vortex gyrotropic mode excited by surface acoustic waves","authors":"R. Lopes Seeger, F. Millo, G. Soares, J. -V. Kim, A. Solignac, G. de Loubens, T. Devolder","doi":"arxiv-2409.05998","DOIUrl":"https://doi.org/arxiv-2409.05998","url":null,"abstract":"The traditional method for exciting spin-wave dynamics in magnetic materials\u0000involves microwave magnetic fields generated by current injection into\u0000inductive antennas. However, there is a growing interest in non-inductive\u0000excitation methods. Magneto-acoustic effects present a viable alternative,\u0000where strains produced by applying voltages to a piezoelectric substrate can\u0000couple to spin-waves in a magnetic film. Recently, it has been proposed that\u0000surface acoustic waves (SAWs) can excite the gyrotropic mode of the vortex\u0000state in a magnetic disk. Here we report on experiments utilizing a magnetic\u0000resonance force microscope to investigate magnetization dynamics in CoFeB\u0000sub-micrometer disks in the vortex state, grown on a Z-cut LiNbO$_3$ substrate.\u0000The device design enables excitation of the gyrotropic mode either inductively,\u0000using an antenna on top of the disks, or acoustically via SAWs launched from an\u0000interdigital transducer. Our modelling indicates that the lattice rotation\u0000{omega}xz generates a localized magneto-acoustic field that displaces the\u0000vortex core from the disk center, initiating the gyration motion. Tuning of the\u0000magneto-acoustic torque acting on the vortex structure is achieved by a\u0000perpendicular magnetic field. These results demonstrate the clear excitation of\u0000the vortex gyrotropic mode by magneto-acoustic excitation.","PeriodicalId":501234,"journal":{"name":"arXiv - PHYS - Materials Science","volume":"181 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integral transform technique for determining stress intensity factor in wave propagation through functionally graded piezoelectric-viscoelastic structure","authors":"Diksha, Soniya Chaudhary, Pawan Kumar Sharma","doi":"arxiv-2409.05472","DOIUrl":"https://doi.org/arxiv-2409.05472","url":null,"abstract":"This study employs an integral transform approach for Love wave propagation\u0000in a rotating composite structure having an interfacial crack. The structure\u0000comprises an initially stressed functionally graded piezoelectric viscoelastic\u0000half-space bonded to a piezoelectric viscoelastic half-space. The study focuses\u0000on two material systems: Epoxy-BNKLBT paired with Epoxy-KNLNTS and Epoxy-BNKLBT\u0000paired with Epoxy-PZT7A. The viscoelastic materials are modeled to reflect\u0000their complex behavior under rotational and stress conditions. The Galilean\u0000transformation is applied to convert the Cartesian coordinates system into a\u0000moving reference frame aligned with the Love wave's propagation. Employing\u0000Bessel function properties, the system is converted into a set of double\u0000integral equations and subsequently reformulated into simultaneous Fredholm\u0000integral equations. Numerical solutions to these Fredholm integral equations\u0000are used to calculate the electric displacement intensity factor (EDIF) and\u0000stress intensity factor (SIF) near the interfacial crack. The key objective of\u0000this study is to visualize the impact of different material parameters, like\u0000piezoelectric constants, dielectric constants, initial stress, interface\u0000electric displacement, interface stress, and rotation, on SIF and EDIF. The\u0000investigations of this study will be helpful for advanced technologies like\u0000surface acoustic wave (SAW) sensors and piezoelectric actuators, as well as to\u0000enhance SAW bio-sensor sensitivity and stability for early cancer detection and\u0000biomedical implants.","PeriodicalId":501234,"journal":{"name":"arXiv - PHYS - Materials Science","volume":"08 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142188198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}