Han Y, Xing W, Yu R, Meng F. Structure stabilization effect of vacancies and entropy in hexagonal WN.
ACTA CRYSTALLOGRAPHICA SECTION B, STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS 2022;
78:678-684. [PMID:
35975833 DOI:
10.1107/s2052520622006096]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 06/08/2022] [Indexed: 06/15/2023]
Abstract
The structural stability of hexagonal tungsten mononitride (WN) has been studied combining scanning transmission electron microscopy and first-principles calculations. The results show that the WC-type WN with vacancies of 6∼8 at% is more stable than the previously proposed MnP-type and NiAs-type structures. Due to the larger vibrational entropy of the WC-type WN, the vacancy concentration required to stabilize the WC-type structure is lower at high temperatures. The results demonstrate the importance of vacancies and configurational and vibrational entropies in the structural stability of compounds synthesized at high temperatures.
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