Computational modeling sheds light on structural evolution in metallic glasses and supercooled liquids

作     者：Jun Ding En Ma 

作者机构：Materials Sciences DivisionLawrence Berkeley National LaboratoryBerkeleyCA 94720USA Department of Materials Science and EngineeringJohns Hopkins UniversityBaltimoreMD 21218USA 

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

年 卷 期：2017年第3卷第1期

页      面：405-416页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：supported by NSF-DMR-1505621 supported by the U.S.Department of Energy,Office of Basic Energy Sciences,Materials Sciences and Engineering Division,through the Mechanical Behavior of Materials Program(KC13)at Lawrence Berkeley National Laboratory under Contract No.DE-AC02-05CH11231 

主　　题：metallic glasses structural 

摘      要：This article presents an overview of three challenging issues that are currently being debated in the community researching on the evolution of amorphous structures in metallic glasses and their parent supercooled *** emphasis is on the valuable insights acquired in recent computational analyses that have supplemented experimental *** first idea is to use the local structural order developed,and in particular its evolution during undercooling,as a signature indicator to rationalize the experimentally observed temperature-dependence of viscosity,hence suggesting a possible structural origin of liquid *** second issue concerns with the claim that the average nearest-neighbor distance in metallic melts contracts rather than expands upon heating,concurrent with a reduced coordination *** postulate is,however,based on the shift of the first peak maximum in the pair distribution function and an average bond length determined from nearest neighbors designated using a distance *** can instead be a result of increasing skewness of the broad first peak,upon thermally exacerbated asymmetric distribution of neighboring atoms activated to shorter and longer distances under the anharmonic interatomic interaction *** third topic deals with crystal-like peak positions in the pair distribution function of metallic *** peak locations can be explained using various connection schemes of coordination polyhedra,and found to be present already in high-temperature liquids without hidden crystal *** also present an outlook to invite more in-depth computational research to fully settle these issues in future,and to establish more robust structure-property relations in amorphous alloys.