First-principles study of transition metal carbides

作者：Damien Connétable · 发表于：Materials Research Express · 年份：2016 · DOI：10.1088/2053-1591/3/12/126502 · 被引用次数：46 · 研究领域：Advanced materials and composites、Metal and Thin Film Mechanics、MXene and MAX Phase Materials

This study investigates the physical properties of transition metal carbides compounds associated with the Nb–C, Ti–C, Mo–C and W–C alloys systems using first-principles calculations. The ground-state properties (lattice parameters, cohesive energies and magnetism) were analyzed and compared to the experimental and theoretical literature. The simulations are in excellent agreement with experimental findings concerning atomic positions and structures. Elastic properties, computed using a finite-differences approach, are then discussed in detail. To complete the work, their lattice dynamics properties (phonon spectra) were investigated. These results serve to establish that some structures, which are mechanically stable, are dynamically unstable.