Effect of Mn doping on mechanical properties and electronic structure of WCoB ternary boride by first-principles calculations

• 来源期刊: 中国物理B（英文版）
• 关键词: Mn doping WCoB electronic structure first-principles calculations
• 年，卷（期）: 2018,（10）
• 页码范围: 519-530
• 页数: 12页
• 语种: 英文
• DOI: 10.1088/1674-1056/27/10/107101

摘要

The first-principles calculations are performed to investigate the structural, mechanical property, hardness, and elec-tronic structure of WCoB with 0, 8.33, 16.67, 25, and 33.33 at.％Mn doping content and W2CoB2 with 0, 10, and 20 at.％Mn doping content. The cohesive energy and formation energy indicate that all the structures can retain good structural stability. According to the calculated elastic constants, Mn is responsible for the increase of ductility and Poisson's ratio and the decrease of Young's modulus, shear modulus, and bulk modulus. By using the population analysis and mechani-cal properties, the hardness is characterized through using the five hardness models and is found to decrease with the Mn doping content increasing. The calculated electronic structure indicates that the formation of a B–Mn covalent bond and a W–Mn metallic bond contribute to the decreasing of the mechanical properties.