Zr_(2)SeB and Hf_(2)SeB:Two new MAB phase compounds with the Cr_(2)AlC-type MAX phase(211 phase)crystal structures  

作　　者：Qiqiang ZHANG Yanchun ZHOU Xingyuan SAN Wenbo LI Yiwang BAO Qingguo FENG Salvatore GRASSO Chunfeng HU 

机构地区：[1]Key Laboratory of Advanced Technologies of Materials,Ministry of Education,School of Materials Science and Engineering,Southwest Jiaotong University,Chengdu 610031,China [2]Science and Technology on Advanced Functional Composite Laboratory,Aerospace Research Institute of Materials&Processing Technology,Beijing 100076,China [3]Hebei Key Lab of Optic–Electronic Information and Materials,College of Physics Science and Technology,Hebei University,Baoding 071002,China [4]State Key Laboratory of Green Building Materials,China Building Materials Academy,Beijing 100024,China

出　　处：《Journal of Advanced Ceramics》2022年第11期1764-1776,共13页先进陶瓷（英文）

基　　金：supported by the National Natural Science Foundation of China(52032011 and 52072311);Outstanding Young Scientific and Technical Talents in Sichuan Province(2019JDJQ0009);Fundamental Research Funds for the Central Universities(2682020ZT61,2682021GF013,and XJ2021KJZK042);the Opening Project of State Key Laboratory of Green Building Materials,and the Project of State Key Laboratory of Environment-friendly Energy Materials(20kfhg17).

摘　　要：The ternary or quaternary layered compounds called MAB phases are frequently mentioned recently together with the well-known MAX phases.However,MAB phases are generally referred to layered transition metal borides,while MAX phases are layered transition metal carbides and nitrides with different types of crystal structure although they share the common nano-laminated structure characteristics.In order to prove that MAB phases can share the same type of crystal structure with MAX phases and extend the composition window of MAX phases from carbides and nitrides to borides,two new MAB phase compounds Zr_(2)SeB and Hf_(2)SeB with the Cr_(2)AlC-type MAX phase(211 phase)crystal structure were discovered by a combination of first-principles calculations and experimental verification in this work.First-principles calculations predicted the stability and lattice parameters of the two new MAB phase compounds Zr_(2)SeB and Hf_(2)SeB.Then they were successfully synthesized by using a thermal explosion method in a spark plasma sintering(SPS)furnace.The crystal structures of Zr_(2)SeB and Hf_(2)SeB were determined by a combination of the X-ray diffraction(XRD),scanning electron microscopy(SEM),and high-resolution transmission electron microscopy(HRTEM).The lattice parameters of Zr_(2)SeB and Hf_(2)SeB are a=3.64398Å,c=12.63223Åand a=3.52280Å,c=12.47804Å,respectively.And the atomic positions are M at 4f(1/3,2/3,0.60288[Zr]or 0.59889[Hf]),Se at 2c(1/3,2/3,1/4),and B at 2a(0,0,0).And the atomic stacking sequences follow those of the Cr_(2)AlC-type MAX phases.This work opens up the composition window for the MAB phases and MAX phases and will trigger the interests of material scientists and physicists to explore new compounds and properties in this new family of materials.

关 键 词：Zr_(2)SeB and Hf_(2)SeB MAB phase MAX phase first-principles calculations thermal explosion synthesis 

分 类 号：TQ174.1[化学工程—陶瓷工业]