We investigate the high-pressure phase diagram of Ti–Te system using first-principles calculations combined with evolutionary crystal structure prediction. Given the isostructural behavior of Se and Te at higher pressures, the same stoichiometric ratios as in the Ti–Se system were found in the Ti–Te system at high pressures. A novel A15 stable phase TiTe is predicted under pressure. Following this, its electronic, mechanical, vibrational, dynamical and superconducting properties at 0 GPa have been systematically scrutinized. The Ti- orbitals occupy mainly at the Fermi level and TiTe exhibits intrinsic metallic property. Meanwhile, the electron-phonon coupling constant is 1.03, and the calculated superconducting transition temperature ( = 0.10–0.15) is 14.2-11 K. Furthermore, we have studied the A15 structural candidates that can be formed by Ti and sulphur group elements under pressure. The mechanism of pressure-enhanced superconductivity present in these structures is also elucidated from a microscopic perspective.

中文翻译：

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Ti-Te 体系新型 A15 相在压力下的电子声子驱动超导


我们利用第一性原理计算结合演化晶体结构预测研究了 Ti-Te 体系的高压相图。鉴于 Se 和 Te 在较高压力下的同构行为，在高压下的 Ti-Te 体系中发现了与 Ti-Se 体系相同的化学计量比。预测在压力下会出现一种新型 A15 稳定相 TiTe。随后，它在 0 GPa 下的电子、机械、振动、动力学和超导特性都得到了系统的审查。 Ti轨道主要占据费米能级，TiTe表现出固有的金属性质。同时，电子-声子耦合常数为1.03，计算出的超导转变温度（= 0.10–0.15）为14.2-11 K。此外，我们还研究了Ti和硫族元素在压力下可以形成的A15候选结构。 。这些结构中存在的压力增强超导机制也从微观角度得到了阐明。