标题：Origin of Ferroelectric Modification: The Thermal Behavior of Dopant Ions
作者：Sun, Dehui; Song, Wei; Li, Lili; Chen, Yuke; Wang, Fulei; Liang, Longyue; Yu, Xin; Li, Yanlu; Sang, Yuanhua; Liu, Hong
作者机构：[Sun, Dehui; Chen, Yuke; Yu, Xin; Liu, Hong] Univ Jinan, Inst Adv Interdisciplinary Res, Jinan 250022, Shandong, Peoples R China.; [Li, Lili; Wang, 更多
通讯作者：Liu, H;Li, YL;Sang, YH;Liu, H;Li, Yanlu
通讯作者地址：[Liu, H]Univ Jinan, Inst Adv Interdisciplinary Res, Jinan 250022, Shandong, Peoples R China;[Li, YL; Sang, YH; Liu, H]Shandong Univ, State Key Lab Cry 更多
来源：CRYSTAL GROWTH & DESIGN
摘要：Ferroelectrics were often modified by dopants for corresponding applied fields. The LiNbO3 (LN) crystal, one of the most attractive ferroelectric functional materials, was often doped by magnesium or some rare-earth ions for corresponding application. Though many kinds of dopants for the LN crystal have been researched, the mechanism of the dopant to regulate the ferroelectricity was never reported. Herein, the origin of ferroelectric modification was investigated from the thermal distortion of the fine lattice structure. It was proved by using the state-of-the-art first-principles approach based on density functional theory that the rare-earth ions and antisite Nb-Li defects are poisonous to the LN lattice structure, which generates the lattice distortion. Furthermore, the lattice distortion evolved into a lattice-plane split with the increasing temperature. On the contrary, the magnesium doped LN crystal keeps the complete LN structure even at 1275 K. Finally, the mechanism of ferroelectric modification was analyzed from the thermal behavior of dopant cations.