Structural effects on the spin-state transition in epitaxially strained LaCoO3 films
Structural effects on the spin-state transition in epitaxially strained LaCoO3 films
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DOI：
10.1103/physrevb.79.054409
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发表时间：
2008-08
影响因子：
3.7
通讯作者：
J. Rondinelli;N. Spaldin
中科院分区：
文献类型：
--
作者：
J. Rondinelli;N. Spaldin
采用密度泛函理论的$\text{LSDA}+U$方法，研究了应变对钙钛矿钴酸镧${\text{LaCoO}}_{3}$自旋态和磁有序的影响.我们表明，虽然应变引起的晶格参数的变化是不足以稳定的非零自旋状态，额外的异质外延对称性约束，特别是八面体旋转的抑制稳定铁磁中间自旋状态。通过与实验数据的比较，为散装材料，我们计算上界的Hubbard $U$值，并描述的作用，现场库仑相互作用在确定的自旋态配置。
Using density-functional theory within the $\text{LSDA}+U$ method, we investigate the effect of strain on the spin state and magnetic ordering in perovskite lanthanum cobaltite, ${\text{LaCoO}}_{3}$. We show that, while strain-induced changes in lattice parameters are insufficient to stabilize a nonzero spin state, additional heteroepitaxial symmetry constraints\char22{}in particular the suppression of octahedral rotations\char22{}stabilize a ferromagnetic intermediate-spin state. By comparing with experimental data for the bulk material, we calculate an upper bound on the Hubbard $U$ value, and describe the role that the on-site Coulomb interaction plays in determining the spin-state configuration.