Magnetic Proximity Effect and Anomalous Hall Effect in Pt/Y3Fe5-xAlxO12 Heterostructures

In this paper, we report an experimental and first-principles calculation study on the anomalous Hall effect (AHE) in Pt/Y3Fe5-xAlxO12 bilayer structures. Using a combinatorial pulsed-laser deposition method, we doped Al3+ ions in the Y3Fe5O12 lattice with different concentrations, which preferentially substitute the tetrahedral Fe3+, leading to significant variation of AHE. A monotonic decrease of anomalous Hall resistance R-AHE with increasing Al3+ doping concentration is observed at a temperature of 5 K, which scales linearly with the magnetic proximity effect- (MPE-)induced magnetic moments in Pt, as calculated using first-principles calculations. Temperature-dependent R-AHE characterizations indicate a sign change in R-AHE at around 100 K, which can be explained by a predominant contribution from spin Hall effect-(SHE-)induced AHE at higher temperatures. Our study demonstrates that the band hybridization and exchange coupling between tetrahedral Fe3+ ions and Pt are the major contributors to the magnetic proximity effect in Pt/YIG heterojunctions.