论文标题
轨道订购的铁磁绝缘状态在拉伸的srcoo $ _ {3} $薄膜
Orbital-ordered ferromagnetic insulating state in tensile-strained SrCoO$_{3}$ thin films
论文作者
论文摘要
在环境压力下，散装srcoo $ _ {3} $是Cubic Perovskite结构中的铁磁（FM）金属。相比之下，外在srcoo $ _ {3} $薄膜的磁性特性，尤其是在高抗拉力应变（$ \ varepsilon \ gtrsim 3 $ \％）下，尚不清楚：先前的计算已经预测了在该方案中在该方案中表现出的反铁磁性（AFM）在最新的实验中表现出更大的良好状态，但指示了FM的指示。在这项工作中，使用第一原理计算，我们对Srcoo $ _ {3} $薄膜的结构，自旋，磁性和轨道状态进行了广泛的搜索。我们的计算表明，在$ 0 <\ varepsilon \ Lessim 2.5 $ \％，srcoo $ _ {3} $倾向于带有InterMediate-spin的FM半金属状态（$ t_ {2g}^{2G}^{5} e_ {g} e_ {g}^1}^{1} $ - nline $ nline $ nline co nline co nline co nline co nline co nline co nline co nline。在$ \ varepsilon \ gtrsim 2.5 $ \％，一种具有高速旋转状态的FM（$ t_ {2g}^{4} e_ {g}^{2}^{2} $ - like）co占主导地位。通过复杂的轨道顺序，合作的Jahn- teller扭曲和八面体倾斜在所有三个晶体轴上，可以实现这种FM绝缘状态。
At ambient pressure, bulk SrCoO$_{3}$ is a ferromagnetic (FM) metal in cubic perovskite structure. By contrast, magnetic properties of epitaxial SrCoO$_{3}$ thin films, especially at high tensile strain ($\varepsilon \gtrsim 3$\%), remain unclear: Previous calculations had predicted antiferromagnetic (AFM) states more energetically favorable in this regime, but recent experiments indicated a FM insulating state. In this work, using first-principles calculations, we perform an extensive search for the structural, spin, magnetic, and orbital states of SrCoO$_{3}$ thin films. Our calculations indicate that at $0 < \varepsilon \lesssim 2.5$\%, SrCoO$_{3}$ favors a FM half-metallic state with intermediate-spin ($t_{2g}^{5}e_{g}^{1}$-like) Co exhibiting $d^{6}\underline L$ character. At $\varepsilon \gtrsim 2.5$\%, a FM insulating state with high-spin ($t_{2g}^{4}e_{g}^{2}$-like) Co dominates. This FM insulating state is achieved via complicated orbital ordering, cooperative Jahn--Teller distortion, and octahedral tilting about all three crystal axes.
