The ability to tune the competition between the in-plane and out-of-plane orientation of magnetization provides a means to construct thermal sensors with a sharp spin re-orientation transition at specific temperatures. We have observed such a tuneable, temperature driven spin re-orientation in structurally amorphous, ferrimagnetic rare earth-transition metal (RE-TM) alloy thin films using scanning transmission X-ray microscopy (STXM) and magnetic measurements. The nature of the spin re-orientation transition in FeGd can be fully explained by a non-equilibrium, nanoscale modulation of the chemical composition of the films. This modulation leads to a magnetic domain pattern of nanoscale speckles superimposed on a background of in-plane domains that form Laudau configurations in micron-scale patterned elements. It is this speckle magnetic structure that gives rise to a sharp two step-reversal mechanism that is temperature dependent. The possibility to balance competing anisotropies through the temperature opens opportunities to create and manipulate topological spin textures.
@article{arxiv.2007.03657,
title = {Anisotropy induced spin re-orientation in chemically-modulated amorphous ferrimagnetic films},
author = {E. Kirk and C. Bull and S. Finizio and H. Sepehri-Amin and S. Wintz and A. K. Suszka and N. S. Bingham and P. Warnicke and K. Hono and P. W. Nutter and J. Raabe and G. Hrkac and T. Thomson and L. J. Heyderman},
journal= {arXiv preprint arXiv:2007.03657},
year = {2020}
}