Electronic Structure Evolution during Martensitic Phase Transition in All-d-Metal Heusler Compounds: The Case of Pd_(2)MnTi  

作　　者：Guijiang Li Gang Wang Enke Liu 李贵江;王刚;刘恩克(College of Materials Science and Engineering,Nanjing Tech University,Nanjing 211816,China;Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]College of Materials Science and Engineering,Nanjing Tech University,Nanjing 211816,China [2]Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China

出　　处：《Chinese Physics Letters》2024年第11期87-92,共6页中国物理快报（英文版）

基　　金：supported by the special fund for introduced talent to initiate scientific research in Nanjing Tech University;the National Natural Science Foundation of China(Grant Nos.52088101 and 52325201);the National Key Research and Development Program of China(Grant No.2023YFA1607400)。

摘　　要：Taking Pd_(2)MnTi as a representative example,we systematically investigate and theoretically reveal the electronic structure evolution during martensitic phase transition in all-d-metal Heusler compounds.The calculation and theoretical analysis suggest that Pd_(2)MnTi is not stable in cubic structure and prone to transform to lowsymmetric tetragonal structure.By tetragonal deformation,the shrinkage of lattice parameters and the decrease of symmetry promote the electron accumulation between Pd and its first nearest neighboring Ti atom,resulting in the increasing covalent hybridization.The occurrence of pseudogap in density of states of tetragonal Pd_(2)MnTi near the Fermi level also verifies the enhancement of covalent bond.Comparatively,the stronger interatomic bond in tetragonal Pd_(2)MnTi,i.e.,covalent bond here,would strengthen interatomic coupling and consequently lower the energy of the material.By the martensitic phase transition,more stable states in energy are achieved.Thus,based on the analysis of electronic structure evolution,the nature of martensitic phase transition is a process wherein symmetry breaking weakens the original weak chemical bonds in high-symmetric parent phase and induces the strong chemical bond to lower the energy of the materials and to achieve a more stable state.This study could help to deepen the understanding of martensitic phase transition and the exploration of novel materials for potential technical applications.

关 键 词：martensitic DEFORMATION TETRAGONAL 

分 类 号：O469[理学—凝聚态物理]