Spin Hall magnetoresistance at Pt/CoFe2O4 interfaces and texture effects

TL;DR

This study investigates how the spin Hall magnetoresistance (SMR) at Pt/CoFe2O4 interfaces varies with crystallographic orientation and interface preparation, revealing the importance of interface quality and composition on spin-dependent phenomena.

Contribution

It demonstrates the dependence of SMR magnitude on interface preparation and orientation, highlighting the role of magnetic ion density and composition at the interface.

Findings

SMR magnitude varies with interface preparation conditions.

Crystallographic orientation affects the spin-mixing conductance.

Optimal SMR achieved with in situ sample preparation.

Abstract

We report magnetoresistance measurements on thin Pt bars grown on epitaxial (001) and (111) CoFe2O4 (CFO) ferrimagnetic insulating films. The results can be described in terms of the recently discovered spin Hall magnetoresistance (SMR). The magnitude of the SMR depends on the interface preparation conditions, being optimal when Pt/CFO samples are prepared in situ, in a single process. The spin-mixing interface conductance, the key parameter governing SMR and other relevant spin-dependent phenomena such as spin pumping or spin Seebeck effect, is found to be different depending on the crystallographic orientation of CFO, highlighting the role of the composition and density of magnetic ions at the interface on spin mixing.