中国物理B ›› 2018, Vol. 27 ›› Issue (8): 86104-086104.doi: 10.1088/1674-1056/27/8/086104

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

First principles study on lattice vibration and electrical properties of layered perovskite Sr2M2O7 (M=Nb, Ta)

Xing Liu(刘星), Hui-Qing Fan(樊慧庆)   

  1. State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, China
  • 收稿日期:2017-12-27 修回日期:2018-05-04 出版日期:2018-08-05 发布日期:2018-08-05
  • 通讯作者: Xing Liu, Hui-Qing Fan E-mail:xingliu_lx@163.com;hqfan3@163.com
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 51672220), the 111 Program of the Ministry of Education of China (Grant No. B08040), the National Defense Science Foundation (Grant No. 32102060303), the Xi'an Science and Technology Foundation, the Shaanxi Provincial Science Foundation and the Gaofeng Project of Northwestern Polytechnical University, China (Grant No. 17GH020824).

First principles study on lattice vibration and electrical properties of layered perovskite Sr2M2O7 (M=Nb, Ta)

Xing Liu(刘星), Hui-Qing Fan(樊慧庆)   

  1. State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, China
  • Received:2017-12-27 Revised:2018-05-04 Online:2018-08-05 Published:2018-08-05
  • Contact: Xing Liu, Hui-Qing Fan E-mail:xingliu_lx@163.com;hqfan3@163.com
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 51672220), the 111 Program of the Ministry of Education of China (Grant No. B08040), the National Defense Science Foundation (Grant No. 32102060303), the Xi'an Science and Technology Foundation, the Shaanxi Provincial Science Foundation and the Gaofeng Project of Northwestern Polytechnical University, China (Grant No. 17GH020824).

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摘要：

In this paper, we performed calculations to investigate the dielectric, piezoelectric properties, Born effective charge (BEC), and spontaneous polarization of Sr2M2O7, the method used in our study was a well-known density functional theory based on first-principles. The optimized results were in good agreement with previous experiments and calculations, which indicates that our calculated method is reasonable. The research we have done suggested that greater piezoelectric components of Sr2Nb2O7 were e31 and e33, and the contributions were derived from the A1. By studying the Born effective charge, it could be seen that the valence of ions changed, and the O of Sr2Nb2O7 were most obviously that caused by the covalent character of ions and the hybridization of O-2p and Nb-4d. The spontaneous polarization of Sr2Nb2O7 in the[001] direction is 25 μC/cm2, while for Sr2Ta2O7, there was no spontaneous polarization in the paraelectric state. Finally, the effect of pressure on the piezoelectric properties were also investigated, the polarization of Sr2Nb2O7 decreased linearly with the increase after pressure. All our preliminary results throw light on the nature of dielectric, piezoelectric properties, Born effective charge, and spontaneous polarization of Sr2M2O7, it was helpful for experimental research, the development of new materials, and future applications.

关键词: Sr2M2O7, first-principles, dielectric and piezoelectric properties, Born effective charge, spontaneous polarization

Abstract:

In this paper, we performed calculations to investigate the dielectric, piezoelectric properties, Born effective charge (BEC), and spontaneous polarization of Sr2M2O7, the method used in our study was a well-known density functional theory based on first-principles. The optimized results were in good agreement with previous experiments and calculations, which indicates that our calculated method is reasonable. The research we have done suggested that greater piezoelectric components of Sr2Nb2O7 were e31 and e33, and the contributions were derived from the A1. By studying the Born effective charge, it could be seen that the valence of ions changed, and the O of Sr2Nb2O7 were most obviously that caused by the covalent character of ions and the hybridization of O-2p and Nb-4d. The spontaneous polarization of Sr2Nb2O7 in the[001] direction is 25 μC/cm2, while for Sr2Ta2O7, there was no spontaneous polarization in the paraelectric state. Finally, the effect of pressure on the piezoelectric properties were also investigated, the polarization of Sr2Nb2O7 decreased linearly with the increase after pressure. All our preliminary results throw light on the nature of dielectric, piezoelectric properties, Born effective charge, and spontaneous polarization of Sr2M2O7, it was helpful for experimental research, the development of new materials, and future applications.

Key words: Sr2M2O7, first-principles, dielectric and piezoelectric properties, Born effective charge, spontaneous polarization

中图分类号:  (First-principles theory)

  • 63.20.dk
71.15.Mb (Density functional theory, local density approximation, gradient and other corrections) 77.90.+k (Other topics in dielectrics, piezoelectrics, and ferroelectrics and their properties)