摘要
基于第一性原理计算,研究了应变作用下EuTiO_3(ETO)薄膜的微观结构、轨道电子态密度,分析其磁性变化以及可能的极化起源.研究发现,对ETO薄膜施加一定程度的应变,无论是压应变还是张应变,体系由顺电相相变到铁电相.极化来源于应变作用下Ti 3d与周围O 2p离子的杂化平衡被打破,Ti原子位置发生偏移.张应变作用下极化沿着原胞平面内y轴方向,而压应变作用下极化则沿着z轴方向.此外,铁磁的势阱大于反铁磁的势阱,说明施加一定程度的应变,晶体的磁性会由反铁磁态相变到铁磁态.
The first principles calculations were used to investigate the crystal microscopic structure, and electron density of states of EuTiO3（ETO） thin film with strains based on the density function theory, and the magnetic order and polarization origin and direction at different strains were analyzed. The results showed that both the compressive strain and tensile strain applied on ETO can induce a phase transition from paraelectric phase to ferroelectric phase. Moreover, the ferroelectric polarization originates from the off-centered shift of Ti atoms owing to the breaking of hybridization balance between Ti 3d and O 2p under the effect of strains. The tensile strain leads to a polarization along planar y axis direction of unit cell, while the polarization follows the z axis direction when the compressive strain is applied. In addition, the ferromagnetic potential wells are larger than antiferromagnetic ones, indicating a magnetic phase from antiferromagnetic to ferromagnetic states by applying a certain degree of strain.
出处
《南通大学学报（自然科学版）》
CAS
2017年第3期60-65,共6页
Journal of Nantong University(Natural Science Edition)
基金
国家自然科学基金项目(11447229)
江苏省自然科学基金项目(BK20130387)
江苏省研究生科研创新项目(KYLX16_0969)
作者简介
王歆钰（1993-），女，硕士研究生.;通信联系人院仲崇贵（1970-），男，教授，主要研究方向为多铁性材料的理论研究.E-mail：chgzhong@ntu.edu.cn
