摘要
Vanadium dioxide VO_(2) is a strongly correlated material that undergoes a metal-to-insulator transition around 340 K.In order to describe the electron correlation effects in VO_(2), the DFT+U method is commonly employed in calculations.However, the choice of the Hubbard U parameter has been a subject of debate and its value has been reported over a wide range. In this paper, taking focus on the phase transition behavior of VO_(2), the Hubbard U parameter for vanadium oxide is determined by using the quasi-harmonic approximation(QHA). First-principles calculations demonstrate that the phase transition temperature can be modulated by varying the U values. The phase transition temperature can be well reproduced by the calculations using the Perdew–Burke–Ernzerhof functional combined with the U parameter of 1.5eV. Additionally,the calculated band structure, insulating or metallic properties, and phonon dispersion with this U value are in line with experimental observations. By employing the QHA to determine the Hubbard U parameter, this study provides valuable insights into the phase transition behavior of VO_(2). The findings highlight the importance of electron correlation effects in accurately describing the properties of this material. The agreement between the calculated results and experimental observations further validates the chosen U value and supports the use of the DFT+U method in studying VO_(2).
作者
孔龙娟
陆雨航
庄新莹
周志勇
胡振芃
Longjuan Kong;Yuhang Lu;Xinying Zhuang;Zhiyong Zhou;Zhenpeng Hu(School of Physics,Nankai University,Tianjin 300071,China)
基金
supported by the National Natural Science Foundation of China (Grant Nos.21933006 and 21773124)
the Fundamental Research Funds for the Central Universities Nankai University (Grant Nos.010-63233001,63221346,63213042,and ZB22000103)
the support from the China Postdoctoral Science Foundation (Grant No.2021M691674)
the Hefei National Laboratory for Physical Sciences at the Microscale (Grant No.KF2020105)。