Synthesis,formation mechanism,and intrinsic physical properties of several As/P-containing MAX phases

作     者：Hongxiang Chen Sheng Li Jun Deng Zhilong Zhang Jianeng Huang Fa Chang Li Huang Shixuan Du Pinqiang Dai Hongxiang Chen;Sheng Li;Jun Deng;Zhilong Zhang;Jianeng Huang;Fa Chang;Li Huang;Shixuan Du;Pinqiang Dai

作者机构：School of Materials Science and EngineeringFujian University of TechnologyFuzhou 350118China Institute of Physics&University of Chinese Academy of SciencesChinese Academy of SciencesBeijing 100190China Fujian Provincial Key Laboratory of Advanced Materials Processing and ApplicationFuzhou 350118China Center for Advanced Energy and Functional MaterialsFujian University of TechnologyFuzhou 350118China Songshan Lake Materials LaboratoryDongguan 523808China CAS Key Laboratory of Vacuum PhysicsBeijing 100049China 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2023年第133卷第2期

页      面：23-31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 the National Science Foundation for Young Scientists of China(No.51902055) the Natural Science Foundation of Fujian Province(Nos.2021J011077,2021J05224,and 2020J01898) 

主　　题：MAX phase Molten-salt synthesis Chemical reaction route Metallic ceramics Formation mechanism Quasi-harmonic approximation 

摘      要：321 phases are an atypical series of MAX phases,in which A=As/P,with superior elastic properties,fea-turing in the MA-triangular-prism bilayers in the crystal *** now,besides Nb 3 As 2 C,the pure phases of the other 321 compounds have not been realized,hampering the study of their intrinsic ***,molten-salt sintering(MSS)and solid-state synthesis(SSS)were applied to synthesize As/P-containing 321 phases and 211 *** the phase composition of the end-product via multiple-phase Rietveld refinement,we found that MSS can effectively improve the purity of P-containing MAX phases,with the phase content up to 99%in Nb_(3)P_(2)C and 75.4(5)%in Nb 2 *** contrast,MSS performed poorly on As-containing MAX phases,only 8.9(4)%for Nb 3 As 2 C and 64(2)%for Nb 2 AsC,as opposed to the pure phases obtained by *** experimental analyses combined with first-principles calculations reveal that the dominant formation route of Nb_(3)P_(2)C is through NbP+Nb+C→Nb_(3)P_(2)***,we found that the benefits of MSS on P-containing MAX phases are on the facilitation of three consid-ered chemical reaction routes,especially on Nb 2 PC+NbP→Nb_(3)P_(2)***,the intrinsic physical properties and Fermi surface topology of two 321 phases consisting of electron,hole,and open orbits are revealed theoretically and experimentally,in which the electron carriers are dominant in electrical *** feasible synthesis methods and the formation mechanism are instructive to obtain high-purity As/P-containing MAX phases and explore new MAX ***,the intrinsic physical properties will give great support for future applications on 321 phases.