Crystal Structure and Electronic Structure of a Novel Hf_3AlN Ceramic

摘要

In this work, we have fabricated a novel ternary aluminum nitride, Hf_3AlN, via a reactive hot pressing method using hafnium and aluminum nitride as starting materials. The crystal structure of Hf_3AlN was established by a combination of ab initio calculation, X-ray diffraction, and electron diffraction analyses. The point group and space group of Hf_3AlN were determined as mmm and Cmcm, respectively. The lattice constants are a = 0.3298 nm, b = 1.135 nm, c = 0.8842 nm and the atomic positions are Hfl at Ac (0, 0.0441,0.2500), Hf2 at 8/(0, 0.3701, 0.0437), Al at 4c (0, 0.7469, 0.2500), and N at 4a (0, 0, 0). Electronic structure analysis demonstrated that Hf_3AlN should possess metallic conductivity and intrinsic damage tolerance. We hope that this work will inspire future experimental research on this Hf-based ternary ceramic.