title: A semiconductive superhard FeB₄ phase from first-principles calculations.
abstract: An oP10-FeB4 phase [H. Gou, et al., Phys. Rev. Lett., 2013, 111, 157002] was recently synthesized based on previous theoretical predictions. In this study, a high-pressure phase of FeB4 (tP10-FeB4) was proposed through first-principles calculations. The tP10-FeB4 structure, which contains two formula units per unit cell, belongs to tetragonal symmetry with the space group P42/nmc. The boron atoms in tP10-FeB4 are present as tetrahedron configurations. Enthalpies as a function of pressure indicate that this new phase is probable to achieve through a phase transition from the oP10-FeB4 phase above ∼65.9 GPa. The softening of acoustic phonon at T points in the Brillouin zone may be the driving force behind the phase transition. Further analyses reveal that the tP10-FeB4 phase is a potential superhard semiconductor.
authors.affiliation: State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, Hebei Province, China. hjl@ysu.edu.cn.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Wang
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.forename: Meng
authors.initials: M
authors.lastname: Hu
authors.forename: Mengdong
authors.initials: M
authors.lastname: Ma
authors.forename: Bo
authors.initials: B
authors.lastname: Xu
authors.forename: Julong
authors.initials: J
authors.lastname: He