We report order of the cobalt electron configuration in ferromagnetic strained epitaxial LaCoO$_3$. Specifically, the presence of charge order is demonstrated from distinct features of the resonant cobalt contribution to superstructure reflections. Density functional theory calculations show the observed order is consistent with the spin-state periodicity predicted to give rise to ferromagnetism in LaCoO$_3$. Through modification of symmetry by strain, concurrent frozen charge and spin-state order are stabilized, giving rise to long range magnetic order.

中文翻译：

---

应变外延LaCoO中的冻结电子构型的铁磁性和电荷顺序$ _3 $

我们报告了铁磁应变外延LaCoO $ _3 $中钴电子构型的顺序。具体地，从共振钴对上层结构反射的贡献的不同特征证明了电荷次序的存在。密度泛函理论计算表明，观测到的阶数与预测会在LaCoO $ _3 $中产生铁磁性的自旋态周期性一致。通过应变改变对称性，稳定了同时冻结的电荷和自旋态有序，从而产生了远距离的磁有序。