Spin Hall magnetoresistance as a probe for surface magnetization in Pt/CoFe${}_2$O${}_4$ bilayers

Abstract

We study the spin Hall magnetoresistance (SMR) in Pt grown $\text{in situ}$ on CoFe${}_2$O${}_4$ (CFO) ferrimagnetic insulating (FMI) films. A careful analysis of the angle-dependent and field-dependent longitudinal magnetoresistance indicates that the SMR contains a contribution that does not follow the bulk magnetization of CFO but it is a fingerprint of the complex magnetism at the surface of the CFO layer, thus signaling SMR as a tool for mapping surface magnetization. A systematic study of the SMR for different temperatures and CFO thicknesses gives us information impossible to obtain with any standard magnetometry technique. On one hand, surface magnetization behaves independently of the CFO thickness and does not saturate up to high fields, evidencing that the surface has its own anisotropy. On the other hand, characteristic zero-field magnetization steps are not present at the surface while they are relevant in the bulk, strongly suggesting that antiphase boundaries are the responsible of such intriguing features. In addition, a contribution from ordinary magnetoresistance of Pt is identified, which is only distinguishable due to the low resistivity of the $\text{in-situ}$ grown Pt.

19 pages, 8 figures, Supplemental Material

References in corpus (13)

• Direct electronic measurement of the spin Hall effect
• Spin Seebeck insulator
• Theory of spin Hall magnetoresistance
• Tuning the spin Hall effect of Pt from the moderately dirty to the superclean regime
• Temperature dependence of spin diffusion length and spin Hall angle in Au and Pt
• Multiferroic Iron Oxide Thin Films at Room-Temperature
• Hanle Magnetoresistance in Thin Metal Films with Strong Spin-Orbit Coupling
• Investigation of induced Pt magnetic polarization in Pt/Y3Fe5O12 bilayers
• Simultaneous detection of the spin-Hall magnetoresistance and the spin-Seebeck effect in Platinum and Tantalum on Yttrium Iron Garnet
• Spin-dependent Seebeck effect in non-local spin valve devices
• Absence of magnetic proximity effects in magnetoresistive Pt/CoFe2O4 hybrid interfaces
• Modulation of pure spin currents with a ferromagnetic insulator
• Control of spin current by a magnetic YIG substrate in NiFe/Al nonlocal spin valves

Cited by in corpus (21)

• Full angular dependence of the spin Hall and ordinary magnetoresistance in epitaxial antiferromagnetic NiO(001)/Pt thin films
• Theory of spin Hall magnetoresistance (SMR) and related phenomena
• Competing effects at Pt/YIG interfaces: spin Hall magnetoresistance, magnon excitations and magnetic frustration
• Efficient spin torques in antiferromagnetic CoO/Pt quantified by comparing field- and current- induced switching
• Theory of Spin Hall Magnetoresistance from a Microscopic Perspective
• Nonlocal magnon spin transport in NiFe${}_2$O${}_4$ thin films
• Magnetic Proximity Effect in Pt/CoFe2O4 Bilayers
• Synthetic antiferromagnetic coupling between ultra-thin insulating garnets
• Magnetoresistance in Hybrid Pt/CoFe2O4 Bilayers Controlled by Competing Spin Accumulation and Interfacial Chemical Reconstruction
• Structural sensitivity of the spin Hall magnetoresistance in antiferromagnetic thin films
• Strong interfacial exchange field in a heavy metal/ferromagnetic insulator system determined by spin Hall magnetoresistance
• Enhanced magnon spin transport in NiFe${}_2$O${}_4$ thin films on a lattice-matched substrate
• Tunable and Enhanced Rashba Spin-Orbit Coupling in Iridate-Manganite Heterostructures
• Spin-Hall magnetoresistance in a low-dimensional magnetic insulator
• Electrical detection of the spin reorientation transition in antiferromagnetic TmFeO${}_3$ thin films by spin Hall magnetoresistance
• Spin Hall magnetoresistance effect from a disordered interface
• Spin Hall magnetoresistance in paramagnetic NdGaO3
• Competing Ordinary and Hanle Magnetoresistance in Pt and Ti Thin Films
• Even-in-magnetic field part of transverse resistivity as a probe of magnetic transitions
• Statistical characterization of the spin Hall magnetoresistance in YIG/Pt heterostructures
• Effect of interface quality on spin Hall magnetoresistance in Pt/MgFe${}_2$O${}_4$ bilayers