Abstract
Perpendicular magnetic anisotropy (PMA) of magnetic materials has received much attention because of its potential application to spintronics devices. In general, the tensely strained (LSMO) layer is easy plane. Here we demonstrate that the tensile LSMO layer will exhibit an out-of-plane magnetic anisotropy if it is sandwiched between two (LSCO) layers. The most remarkable observation is that the PMA enhances with the increase of the Sr content in LSCO. It is for and for . This value is two orders of magnitude greater than that obtained by compressively straining the LSMO film . Analysis of high resolution lattice image shows the formation of perovskite/brownmillerite-type interfaces in the multilayers: Brownmillerite-like lattice structure forms in the interfacial layers of LSCO, resulting in a coherent tilting of adjacent octahedra. This in turn leads to, as evidenced by the analysis of x-ray linear dichroism, selective orbital occupation thus spin reorientation. There is evidence that the brownmillerite-structured LSCO is more easily formed when is high, which explains the growth of anisotropy constant with the increase of Sr content.
- Received 17 December 2018
- Revised 26 July 2019
DOI:https://doi.org/10.1103/PhysRevB.100.094432
©2019 American Physical Society