黄红伟
,
DONG Ming
,
YE ZuO-Guang
,
冯锡淇
无机材料学报
doi:10.3321/j.issn:1000-324X.2002.01.005
完成了钆离子(Gd3+)掺杂钨酸铅晶体在40～600°C、1～106Hz范围内介电性能的测量.在升温过程中观察的典型的介电弛豫峰,记为α峰,其激活能为0.50+0.01eV,频率因子v=1.44×109.而在降温过程中,除α峰外还出现了另一介电弛豫峰,记为β峰,其激活能为0.51+0.02eV,频率因子v=2.44×106.α峰和β峰均可用Debye方程来描述,而其相对强度呈此消彼长的趋势.分析了Gd:PWO中两种介电弛豫峰的起因及其相互关系,并讨论了它们与PWO晶体闪烁性能变化之间的关系.
关键词:
介电弛豫
,
掺Gd钨酸铅晶体
,
偶极缺陷
Physical Review B
In a recent publication [S. Dong et al., Phys. Rev. Lett. 103, 127201 (2009)], two (related) mechanisms were proposed to understand the intrinsic exchange bias present in oxides heterostructures involving G-type antiferromagnetic perovskites. The first mechanism is driven by the Dzyaloshinskii-Moriya interaction, which is a spin-orbit coupling effect. The second is induced by the ferroelectric polarization, and it is only active in heterostructures involving multiferroics. Using the SrRuO(3)/SrMnO(3) superlattice as a model system, density-functional calculations are here performed to verify the two proposals. This proof-of-principle calculation provides convincing evidence that qualitatively supports both proposals.
关键词:
thin-films;weak ferromagnetism;superlattices;anisotropy;bifeo3;srruo3;model
