Solids that are also liquids: elastic tensors of superionic materials  

作　　者：Giuliana Materzanini Tommaso Chiarotti Nicola Marzari 

机构地区：[1]Theory and Simulations of Materials(THEOS),École Polytechnique Fédérale de Lausanne,CH-1015 Lausanne,Switzerland [2]National Centre for Computational Design and Discovery of Novel Materials(MARVEL),École Polytechnique Fédérale de Lausanne,CH-1015 Lausanne,Switzerland [3]Present address:Institute of Condensed Matter and Nanosciences,UniversitéCatholique de Louvain,B-1348 Louvain-la-Neuve,Belgium

出　　处：《npj Computational Materials》2023年第1期2252-2264,共13页计算材料学（英文）

基　　金：This work was supported by the Swiss National Science Foundation(SNSF)and its National Centre of Competence in Research MARVEL on“Computational Design and Discovery of Novel Materials”(grant number 182892,G.M.,N.M.).We acknowledge computational support from the Swiss National Supercomputing Centre CSCS(projects s1073,s836,and mr28).Fruitful discussions with Claire Villevieille,Aris Marcolongo,and Leonid Kahle are gratefully acknowledged.

摘　　要：Superionics are fascinating materials displaying both solid- and liquid-like characteristics: as solids, they respond elastically to shearstress;as liquids, they display fast-ion diffusion at normal conditions. In addition to such scientific interest, superionics aretechnologically relevant for energy, electronics, and sensing applications. Characterizing and understanding their elastic propertiesis, e.g., urgently needed to address their feasibility as solid-state electrolytes in all-solid-state batteries. However, static approachesto elasticity assume well-defined reference positions around which atoms vibrate, in contrast with the quasi-liquid motion of themobile ions in fast ionic conductors. Here, we derive the elastic tensors of superionics from ensemble fluctuations in the isobaric-isothermal ensemble, exploiting extensive Car-Parrinello simulations. We apply this approach to paradigmatic Li-ion conductors,and complement with a block analysis to compute statistical errors. Static approaches sampled over the trajectories oftenoverestimate the response, highlighting the importance of a dynamical treatment in determining elastic tensors in superionics.

关 键 词：IONIC liquids ENSEMBLE 

分 类 号：TB3[一般工业技术—材料科学与工程]