Optical Measurements of Epitaxially Grown Ferrimagnetic Insulator Thin Films*

Ferrimagnetic insulators exhibit attractive properties for low-loss spintronic applications. Recently, multiple groups have reported the detection of chiral magnetism and the topological Hall effect in Pt/Tm₃Fe₅O₁₂ (TmIG) bilayers, suggesting a promising perspective for hosting small skyrmions. We investigate Tm₃Fe₅O₁₂ thin films with atomically sharp interfaces and properties tunable via eptaxial strain. Sensitive magneto-optical Kerr effect measurements allow us to compare a series of samples with TmIG thickness in the range of 1.9 to 10 nm.