中国物理B ›› 2024, Vol. 33 ›› Issue (7): 76102-076102.doi: 10.1088/1674-1056/ad3ef6
Xiao-Long Pan(潘小龙)1,2, Hao Wang(王豪)2, Lei Liu(柳雷)2, Xiang-Rong Chen(陈向荣)1,†, and Hua-Yun Geng(耿华运)2,3,‡
Xiao-Long Pan(潘小龙)1,2, Hao Wang(王豪)2, Lei Liu(柳雷)2, Xiang-Rong Chen(陈向荣)1,†, and Hua-Yun Geng(耿华运)2,3,‡
摘要: Mn$_{3}$TeO$_{6}$ (MTO) has been experimentally found to adopt a $P2_1/n$ structure under high pressure, which exhibits a significantly smaller band gap compared to the atmospheric $R\bar{3}$ phase. In this study, we systematically investigate the magnetism, structural phase transition, and electronic properties of MTO under high pressure through first-principles calculations. Both $R\bar{3}$ and $P2_1/n$ phases of MTO are antiferromagnetic at zero temperature. The $R\bar{3}$ phase transforms to the $P2_1/n$ phase at 7.58 GPa, accompanied by a considerable volume collapse of about 6.47%. Employing the accurate method that combines DFT$+U$ and GW, the calculated band gap of $R\bar{3}$ phase at zero pressure is very close to the experimental values, while that of the $P2_1/n$ phase is significantly overestimated. The main reason for this difference is that the experimental study incorrectly used the Kubelka-Munk plot for the indirect band gap to obtain the band gap of the $P2_1/n$ phase instead of the Kubelka-Munk plot for the direct band gap. Furthermore, our study reveals that the transition from the $R\bar{3}$ phase to the $P2_1/n$ phase is accompanied by a slight reduction in the band gap.
中图分类号: (Crystallographic aspects of phase transformations; pressure effects)