Spin Hall magnetoresistance in paramagnetic NdGaO3

Abstract

In recent years, spin Hall magnetoresistance (SMR) has emerged as an efficient way to probe the spontaneous magnetization state in ordered magnetic systems, by electrical current. Less known is its versatility as a probe of materials that do not possess spontaneous magnetization such as in paramagnets. In this work, SMR is used to probe paramagnetic NdGaO3(NGO), a rare earth oxide, possessing a sizable spin orbit interaction (L=6). NGO has not been investigated earlier for its efficiency in propagating spins. We have performed extensive temperature and angle dependentmagnetoresistance (ADMR) studies along dissimilar crystallographic axes in NGO, using platinum (Pt) as spin injector and detector and utilizing (inverse) spin Hall effect. We find a close correlation between the temperature dependence of the ADMR response with magnetization in NGO and a linear current bias dependence of the ADMR amplitudes. These are chacteristics of SMR effect in Pt/NGO, arising from the torque acting on localized moments in NGO and considering crystal field induced intermultiplet transitions with temperature. Control experiments on Pt/SrTiO3 and Pt/SiO2 devices were also carried out in order to validate the observed SMR response in Pt/NGO bilayer and to rule out magnetoresistive contributions from Pt.

Observation of magnetization surface textures of the van der Waals antiferromagnet FePS3 by spin Hall magnetoresistance

“…This happens after a spin-flop transition, i.e., when the Néel vector aligns normal to the applied magnetic field [8,9]. SMR has been observed in paramagnetic CoCr 2 O 4 [10], amorphous yttrium iron garnet (YIG) [11], Cr 2 O 3 [12], NdGaO 3 [13], and gadolinium gallium garnet (GGG) [14]. The SMR revealed magnetic phase transitions in α-Fe 2 O 3 [15], CoCr 2 O 4 [10], and DyFeO 3 [16] and magnetic domain structures [17].…”

Strain-driven antiferromagnetic exchange interaction in SrMnO3 probed by phase-shifted spin Hall magnetoresistance

“…A sizable contribution from HMR at low temperature is excluded, as this would result in a a 90 • phase shift in β, which is not the case. WAL, though known to contribute in β and γ directions in Pt [32,42] due to the strong spin-orbit coupling at temperatures below 50 K, is not a dominant contributor in our case, as the out-of-plane direction has a low resistance with respect to the in-plane direction, which shows a higher resistance.…”

Probing the Spatial Variation of Magnetic Order in Strained SrMnO3 Thin Films Using Spin Hall Magnetoresistance

“…SMR has proven to be an effective tool for studying magnetic order, initially demonstrated for ferromagnetic order, [12][13][14] and thereafter shown to reveal paramagnetic, antiferromagnetic order, and even complex magnetic order in spin-spiral and skyrmionic systems. [15][16][17][18] The dependence of SMR on surface magnetic moments, rather than the net magnetization in the material, makes it particularly potent for investigating surface antiferromagnetic order. We show how this surface magnetic order, which is independent of film thickness and its spatial variation, can be read by designing devices of different sizes, revealing the nature of the underlying magnetic domains.…”