Interfacial Tm3+ moment-driven anomalous Hall effect in Pt/Tm3Fe5O12 heterostructure

We performed anomalous Hall effect (AHE) measurements in Pt/Tm3Fe5O12 (Pt/TmIG) bilayers grown on (1 1 0) and (1 1 1)-oriented Gd3Ga5O12 (GGG) substrates (Pt/110TmIG and Pt/111TmIG). Qualitative differences were observed in the two sets of samples: at low magnetic fields only Pt/111TmIG displays square AHE loop, while Pt/110TmIG exhibits non-hysteretic AHE behavior. Systematic temperature-dependent AHE measurements in Pt/111TmIG showed double switching events of AHE loops below 30 K, which was attributed to the larger moment of Tm3+ sublattice at low temperatures and was consistent with earlier theoretical calculations [A. Lehmann-Szweykowska et al., Phys. Rev. B 37, 459 (1988)]. Our results confirmed the strong coupling of Tm3+ magnetic moment with the lattice and the crucial role of the interfacial structure, suggesting a way to detect rare earth moment switching in iron garnets by electrical measurements.