Enhancement of spin-charge interconversion efficiency by interface engineering in all oxide La0.3Sr0.7MnO3/SrIrO3 system

Spin-charge interconversion in complex oxide SrIrO3 has been studied extensively. Spin Hall angle of SrIrO3 thin film has been reported, varying from 0.5^[1][2] to 1^[3]. Given the large resistivity mismatch between semimetal SrIrO3 thin films and typical metal ferromagnets such as CoFeB, CoFe and NiFe, spurious effects and current shunting would be unavoidable in transport measurements. The oxide ferromagnet La0.3Sr0.7MnO3 (LSMO) exhibits high Curie temperature, small coercive field and resistance comparable to SrIrO3 thin films, making it a more suitable candidate for the study of intrinsic spin Hall effects in SrIrO3 thin films. Also, in situ epitaxial growth of LSMO/SrIrO3 bilayer system by PLD provides us a platform for engineering the bilayer interface, realizing a fine control of spin dependent interface properties such as effetive spin mixing conductance (g^↑↓). g^↑↓ that is one orders higher than NiFe/2DES, two orders higher than YIG/Heavy metals has been measured.
[1]. A.S.Everhardt. Phys. Rev. Materials 3, 051201 (2019).
[2].T.Nan. PNAS 116 (33) 16186-16191 (2019).
[3].HL. Wang. Appl. Phys. Lett.114, 232406 (2019).