Tunable compensation temperature through ferromagnetic coupling in perpendicular Tb₃Fe₅O₁₂/Eu₃Fe₅O₁₂ bilayer heterostructure

Abstract

Rare-earth ion garnets (ReIG) with magnetization compensation are being extensively studied, such as in the ferrimagnetic insulator (FMI)/heavy metal (HM) heterostructures, with primary focus on the interface effect between single-layer garnets and HM. Here, we study the anomalous Hall behavior of bilayer garnet in Tb3Fe5O12 (TbIG)/Eu3Fe5O12 (EuIG)/Pt system. TbIG (30 nm)/EuIG (t nm) films with strong perpendicular magnetic anisotropy (PMA) were deposited on single-crystal Gd3Ga5O12 (GGG) (1 1 1) substrates using pulsed laser deposition. Subsequently, a 5-nm Pt layer was sputtered and patterned into Hall bars. Tunable compensation temperature (Tcomp) was achieved in the system by changing the thickness of EuIG, which is ascribed to the ferromagnetic coupling of Fe sublattices in the two different garnets. This study provides guidance for designing garnet spintronic devices with controllable compensation behavior.