DFT-assisting discovery and characterization of a hexagonal MABphase V_(3)PB_(4)  

作　　者：Hang Yin Xiaodong He Jinze Zhang Guangping Song Yongting Zheng Yuelei Bai 

机构地区：[1]National Key Laboratory of Science and Technology on Advanced Composites in Special Environments and Center for Composite Materials and Structures,Harbin Institute of Technology,Harbin,150080,China

出　　处：《Journal of Materiomics》2023年第6期1141-1150,共10页无机材料学学报（英文）

基　　金：supported by the National Natural Science Foundation of China(Grant No.51972080).

摘　　要：A 314-type MAB phase V_(3)PB_(4)with hexagonal crystal structure is synthesized by self-propagating high temperature combustion synthesis(SHS),with the help of the full first-principles predictions for the phase stability and adiabatic combustion temperature of SHS.Using XRD and TEM,V_(3)PB_(4)crystallizes in the space group of P6m2,with the lattice parameters a?3.030Åand c=9.148Å,of much interest,well with the predicted one.Furthermore,the electronic structure,chemical bonding,and elastic properties of hex-V_(3)PB_(4)are predicted by first-principles.No bandgap around Fermi energy indicates its electronic conductor.And the strong covalent bonding is present between the B and V atoms with,significantly,much weaker V-P bond.With the help of the theoretical model of bond stiffness,the significantly high ratio of bond stiffness of weakest bonds to the strongest ones(0.873)of hex-V_(3)PB_(4)indicates its poor damage tolerance and fracture toughness.The high bond stiffness results in its high moduli in comparison with other MAB phases.As the number of inserted P atoms increases,the engineering elastic modulus decrease,without the price of an increase in density.

关 键 词：MAB phase Borides HEXAGONAL First principles Combustion synthesis 

分 类 号：TQ17[化学工程—硅酸盐工业]