Departamento de Física Aplicada III, Universidad Complutense de Madrid, Madrid, 28040, Spain.
Nano Lett. 2011 Mar 9;11(3):973-6. doi: 10.1021/nl1034896. Epub 2011 Feb 10.
Certain cobalt oxides are known to exhibit ordered Co spin states, as determined from macroscopic techniques. Here we report real-space atomic-resolution imaging of Co spin-state ordering in nanopockets of La(0.5)Sr(0.5)CoO(3-δ) thin films. Unlike the bulk material, where no Co spin-state ordering is found, thin films present a strain-induced domain structure due to oxygen vacancy ordering, inside of which some nanometer sized domains show high-spin Co ions in the planes containing O vacancies and low-spin Co ions in the stoichiometric planes. First-principles calculations provide support for this interpretation.
某些钴氧化物已知表现出有序的 Co 自旋态，这是从宏观技术确定的。在这里，我们报告了 La(0.5)Sr(0.5)CoO(3-δ) 薄膜纳米口袋中 Co 自旋态有序的实空间原子分辨率成像。与没有发现 Co 自旋态有序的体材料不同，薄膜由于氧空位有序而呈现出应变诱导的畴结构，其中一些纳米尺寸的畴在含有 O 空位的平面中显示出高自旋 Co 离子，而在化学计量平面中显示出低自旋 Co 离子。第一性原理计算为这一解释提供了支持。
