First-Principle Prediction of Phase Stability, Electronic and Elastic Properties Study of the M n+1 AN n (A = Al, Si, M
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First-Principle Prediction of Phase Stability, Electronic and Elastic Properties Study of the Mn+1ANn (A = Al, Si, M = Ti, Zr, Hf) Qingyun Chen1 • Xuhai Li2 • Bin Ye1 • Liangbin Xiong3
Submitted: 14 July 2020 / in revised form: 26 September 2020 / Accepted: 30 October 2020 ASM International 2020
Abstract Theoretical prediction is the most important method for discovering new structure. The stability of the nitride MAX phase (N-MAX) Mn?1ANn, (A = Al, Si, M = Ti, Zr, Hf) was studied using first principles. The formation energy analysis of the competitive phases shows that N-MAX tends to form the larger n-index M4AN3 structure. The formation energy of the Mn?1SiNn system is higher than that of the Mn?1AlNn system, indicating that the Mn?1AlNn system has greater phase stability and experimental synthesis possibility than the Mn?1SiNn system. In all computing systems, the formation energy of Hfn?1AlNn is the lowest, indicating the largest synthesis possibility. Among all the considered structures, Hf2AlN is the material with the best comprehensive performance, such as the bulk modulus reaches 800 GPa. Due to its high elastic anisotropy, Hf4SiN3 is the excellent candidate for the precursor of MXene 2D nanosheets. The study provides a theoretical prediction for the synthesis of potentially undiscovered phases in the N-MAX systems.
& Qingyun Chen [email protected] Bin Ye [email protected] Liangbin Xiong [email protected] 1
School of Science, Guilin University of Technology, Guilin 541004, China
2
National Key Laboratory of Shock Wave and Detonation Physics, Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang 621010, China
3
Guangdong Polytechnic Normal University, Guangzhou 510665, China
Keywords elastic constants first principle formation energy nitride MAX phases phase stability
1 Introduction Recent the ternary transition metal carbides or nitrides socalled MAX phases, due to its excellent dual performance of ceramics and metals, such as low density, remarkable thermal shock resistance, durability and tough damage tolerance and high oxidation resistance,[1-6] have attracted considerable interest in many applications.[7,8] Up to now, more than 70 varieties of MAX phases were reported. MAX phases share a general formula of Mn?1AXn (where n ranges from 1 to 3, M is an early transition metal, A is a III or IV element, X is carbon or nitrogen). The crystal structure of these MAX phase is composed of ceramic-like M-X atomic layers with strong bonds and A layers which are weakly bonded to M. According to the different of X atoms, the MAX phases can divide into carbide MAX phases (C-MAX) and nitride MAX phases (N-MAX). The C-MAX is one of the most studied species in the MAX phase family. For example, Ti2AlC and Ti3SiC2 have received extensive attention.[1,2,5,9] Barsoum et al.[2,7] have reported the excellent mechanical properties of Ti2AlC and Ti3SiC2. In comparison, some N-MAX exhibit superior performance over C-MAX. For example, the compressibility of Ti2AlN along the a a
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