A two-sublattice ferrimagnet undergoes a transition from a collinear to canted magnetic phase at magnetic field oriented along an easy magnetization direction. In this work, we study the transition by means of the magneto-optical Faraday effect in a thin film of compensated iron garnet (Lu3−xBix)(Fe5−y−zGayAlz)O12 grown on Gd3Ga5O12 substrate. In the immediate vicinity of the compensation temperature a precursor of the transition with a complex shape was observed. Using a special sample with variable thickness we demonstrate an interfacial origin of the precursor. Diffusion of gadolinium from the substrate into the film forms a thin intermixed layer with enhanced magnetization. It induces an extended inhomogeneous magnetic structure in the film. A two-step shape of the precursor appears due to an easy-plane anisotropy of the intermixed magnetic layer. We emphasize that an effective width of the inhomogeneous magnetization distribution in the film grows enormously while approaching the compensation temperature.
@article{arxiv.2201.00134,
title = {Giant widening of interface magnetic layer in almost compensated iron garnet},
author = {Y. B. Kudasov and M. V. Logunov and R. V. Kozabaranov and I. V. Makarov and V. V. Platonov and O. M. Surdin and D. A. Maslov and A. S. Korshunov and I. S. Strelkov and A. I. Stognij and V. D. Selemir and S. A. Nikitov},
journal= {arXiv preprint arXiv:2201.00134},
year = {2022}
}