Temperature-dependent periodicity halving of the in-plane angular magnetoresistance in La0.67Sr0.33MnO3 thin films on LaAlO3

Strain-engineering is used as a tool to alter electronic and magnetic properties like anisotropy energy. This study reports the different angle-dependent magnetoresistance properties of the strain-engineered La0.67Sr0.33MnO3 (LSMO) thin films, grown on LaAlO3, compared to their bulk analogs. Upon increasing temperature, a symmetry change from fourfold [cos(4θ)] to twofold [cos(2θ)] is observed in the angle-dependent resistance measurements. This systematic study with increasing temperature allows us to define three distinct temperature-dependent phases. The fourfold symmetric signal originates from magnetocrystalline anisotropy, whereas the twofold symmetric signal is believed to be the conventional anisotropic magnetoresistance. Our observations show that strain-engineering creates the possibility to manipulate the anisotropy, which, for example, can ultimately lead to observations of noncollinear quasi-particles like skyrmions in single layer thin films of LSMO.
This work was realized using NanoLab NL facilities and is a part of the research program Skyrmionics: Towards New magnetic Skyrmions and Topological Memory (Project No. 16SKYR04). A.A.B. acknowledges financial support from the Netherlands Organisation for Scientific Research (NWO). We thank G. R. Blake, M. V. Mostovoy, A. Das, D. Ottomano, J. J. L. van Rijn, E. P. Vallabhaneni, P. Zhang, A. S. Goossens, and S. Chen for useful scientific discussions and J. G. Holstein and H. H. de Vries for technical assistance.