Site dependence of surface dislocation nucleation in ceramic nanoparticles

作     者：Jonathan Amodeo Emile Maras David Rodney 

作者机构：Univ LyonCNRSINSA LyonUCBLMATEISUMR5510VilleurbanneFrance Universitéde LyonUniversitéClaude Bernard Lyon 1CNRSInstitut Lumière MatièreVilleurbanneFrance 

出 版 物：《npj Computational Materials》 (计算材料学（英文）)

年 卷 期：2021年第7卷第1期

页      面：564-570页

核心收录：

学科分类：07[理学] 070205[理学-凝聚态物理] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0702[理学-物理学] 

主　　题：deformation dislocation ceramic 

摘      要：The extremely elevated strength of nanoceramics under compression arises from the necessity to nucleate highly energetic dislocations from the surface,in samples that are too small to contain pre-existing ***,we investigate the site dependence of surface dislocation nucleation in MgO nanocubes using a combination of molecular dynamics simulations,nudgedelastic-band method calculations and rate theory *** an original simulation setup,we obtain a complete mapping of the potential dislocation nucleation sites on the surface of the nanoparticle and find that,already at intermediate temperature,not only nanoparticle corners are favorable nucleation sites,but also the edges and even regions on the side surfaces,while other locations are intrinsically *** are discussed in the context of recent in situ TEM experiments,sheding new lights on the deformation mechanisms happening during ceramic nanopowder compaction and sintering processes.