Magnéli相亚氧化钛的莫特相变和磁电性能的模拟计算

Simulation and calculation of the Mott phase transition and magnetroelectric performance of Magnéli phase titanium suboxides

基于密度泛函理论框架下的第一性原理平面波超软赝势方法,构建纯的单胞与金红石型和锐钛矿型TiO1.9375超胞模型,并对模型进行了几何结构优化、能带结构分布和态密度分布的计算.结果表明,与纯的单胞相比,金红石和锐钛矿Magnéli相TiO1.9375体系体积均变大,稳定性略下降,而且都发生了莫特相变.其中锐钛矿Magnéli相亚氧化钛表现没有磁性,金红石Magnéli相亚氧化钛有磁性.锐钛矿Magnéli相亚氧化钛的导电性能比金红石Magnéli相亚氧化钛强.计算结果与实验结果相一致.

The pure and Magnéli phase titanium suboxides for both rutile and anatase supercell models of TiO1.9375 were structured by using first-principles plane-wave ultrasoft pseudopotential method based on the density functional theory; the geometry optimizations, the band structures, and density of states of these models were calculated. Results show that the volumes become greater for Magnéli phase titanium suboxides in both rutile and anatase; meanwhile, the stability may reduce slightly, leading to a Mott transition. The nonmagnetic property of anatase titanium suboxides, and the magnetic property of rutile titanium suboxides, as wall as the conductive property of anatase titanium suboxides are higher than rutile titanium suboxides, in agreement with the experimental results.