铁电材料PbTiO₃晶体结构和电子结构的杂化泛函研究  

The Crystal Structure and Electronic Structure of Ferroelectric PbTiO3: A Hybrid Functional Approach

作　　者：王鹏 周琚 蔡田怡 雎胜 

机构地区：[1]苏州大学物理与光电·能源学部,江苏苏州

出　　处：《应用物理》2017年第5期159-164,共6页Applied Physics

摘　　要：基于杂化泛函理论,我们考察了长程Hartree-Fork项在交换关联势中所占比例(α)对铁电材料PbTiO3晶体结构和电子结构的影响。我们发现基于PBE交换关联势,当α等于0.325时杂化泛函所得的带隙值与实验结果相吻合。另外,基于PBE和PW交换关联势我们分别研究了α对晶体结构的影响,基于PBE交换关联势的结果与实验值相差较大。而基于PW交换关联势的计算表明,当α等于0.2时,计算所得到的晶体结构与实验结果比较吻合,但此时带隙值却小于实验值。这些结果表明杂化泛函对于铁电材料PbTiO3的适用性还有待商榷。Based on the hybrid functional theory, we investigated the effect of the long range Hartree-Fork term on the crystal structure and electronic structure of ferroelectric PbTiO3. It is found that the band gap based on the PBE exchange correlation potential with α of 0.325 is in agreement with experimental result. In addition, we studied the influence of α on the crystal structure with PBE and PW exchange correlation potential, respectively. We found that PW could give a reasonable crystal structure when α is around 0.2. The band gap here, however, is less than the experimental value. Therefore, these findings indicate that the hybrid functional approach may be not suitable for ferroelectric PbTiO3.

关 键 词：带隙 杂化泛函 第一性原理 PbTiO₃ 

分 类 号：O64[理学—物理化学]