Epitaxial strain effects in the spinel ferrites CoFe2O4 and NiFe2O4 from first principles
Epitaxial strain effects in the spinel ferrites CoFe2O4 and NiFe2O4 from first principles
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DOI：
10.1103/physrevb.82.104117
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发表时间：
2010-09-23
影响因子：
3.7
通讯作者：
Ederer, Claude
中科院分区：
文献类型：
--
作者：
Fritsch, Daniel;Ederer, Claude
反尖晶石CoFe_2O_4和NiFe_2O_4，这在过去的几年中一直是特别感兴趣的人工多铁性异质结构的积木和可能的自旋过滤器材料，通过密度泛函理论计算进行了研究。我们解决的外延应变对磁晶各向异性的影响，并表明，在协议与实验观察，拉伸应变有利于垂直各向异性，而压缩应变有利于面内取向的磁化。我们计算的CoFe_2 O_4和NiFe_2 O_4的磁致伸缩常数λ（100）分别为-220 ppm和-45 ppm，与实验数据吻合得很好。我们分析了不同的阳离子的安排，用于代表反尖晶石结构的效果，并表明，本地自旋密度近似加U和广义梯度近似加U允许这些材料的一个很好的定量描述。我们的研究结果开辟了途径，为进一步的计算研究尖晶石铁氧体。
The inverse spinels CoFe2O4 and NiFe2O4, which have been of particular interest over the past few years as building blocks of artificial multiferroic heterostructures and as possible spin-filter materials, are investigated by means of density-functional theory calculations. We address the effect of epitaxial strain on the magneto-crystalline anisotropy and show that, in agreement with experimental observations, tensile strain favors perpendicular anisotropy whereas compressive strain favors in-plane orientation of the magnetization. Our calculated magnetostriction constants lambda(100) of about -220 ppm for CoFe2O4 and -45 ppm for NiFe2O4 agree well with available experimental data. We analyze the effect of different cation arrangements used to represent the inverse spinel structure and show that both local spin-density approximation plus U and generalized gradient approximation plus U allow for a good quantitative description of these materials. Our results open the way for further computational investigations of spinel ferrites.