Strain dependent structure and anomalous Hall effect in Pt/Tb3Fe5O12/Ga3Gd5O12 heterostructure grown on Y3Al5O12 substrates

Abstract

We systematically investigate the strain-dependent microstructure and anomalous Hall effect in Pt/Tb3Fe5O12 (TbIG) grown on (1 1 1)-oriented Y3Al5O12 (YAG) substrates with different thickness of Ga3Gd5O12 (GGG) buffer layer. Structural measurements indicated that the out-of-plane lattice spacing of TbIG layers firstly increased with the rising thickness of GGG (tG) and then decreased, which was attributed to the impact of the buffer layer on strain relaxation of the epitaxial films. A variation of compensation temperature was found at tG about 30 nm. Furthermore, both the anomalous Hall resistance and its sign change temperature increased and then kept constant with increasing tG. Our results indicated that strain played a key role to tune the physical properties of Pt/TbIG/GGG heterostructures, providing a possible approach to tune the spin-orbital coupling in heavy metal/ferromagnetic insulator system by strain engineering.