Spin pump and probe in lanthanum strontium manganite/platinum bilayers

Abstract

Ferromagnetic resonance driven spin pumping (FMR-SP) is a novel method to transfer spin current from the ferromagnetic (FM) layer into the adjacent normal metal (NM) layer in an FM/NM bilayer system. Consequently, the spin current could be probed in NM layer via inverse spin Hall effect (ISHE). In spite of numerous ISHE studies on FM/Pt bilayers, La0.7Sr0.3MnO3(LSMO)/Pt system has been less explored and its relevant information about interface property (characterized by spin mixing conductance) and spin-charge conversion efficiency (characterized by spin Hall angle) is a matter of importance for the possible applications of spintronic devices. In this work, the technique of FMR-SP has been applied on two series of LSMO/Pt bilayers with the thickness of each layer being varied. The thickness dependences of ISHE voltage allow to extract the values of spin mixing conductance and spin Hall angle of LSMO/Pt bilayers, which are (1.8 ± 0.4) × 1019 m−2 and (1.2 ± 0.1) % respectively. In comparison with other FM/Pt systems, LSMO/Pt has comparable spin current density and spin mixing conductance, regardless its distinct electronic structure from other ferromagnetic metals.

Low-temperature anomalous spin correlations and Kondo effect in ferromagnetic SrRuO3/LaNiO3/La0.7Sr0.3MnO3Ghosh1, Tanguturi2, Pramanik3 et al. 2019Phys. Rev. B19060View full textAdd to dashboardCite

“…From the in-plane and out-of-plane ferromagnetic resonance (FMR) spectra, the estimated volume and surface magnetic anisotropies are, K ν ∼ 4.04 × 10 5 J/m 3 (3.31×10 5 J/m 3 ) and K s ∼ -9.57×10 −4 J/m 2 (-6.68 ×10 −4 J/m 2 ) for the TL (001) (TL (111) ). These anisotropy values are in good agreement with the earlier reports 97 . These TLs exhibit one order higher in magnitude of Gilbert damping constant as compared to the single layer LSMO and LSMO/Pt, which indicates the slowdown in the magnetization while transferring the spin to LSMO through LNO layer.…”

“…Here, M s is the saturation magnetization, γ represents the gyromagnetic ratio, α 0 is the residual Gilbert constant and g ↑↓ represents spin mixing conductance. For the current TL system on (001) and (111) the magnitude of spin conductance is estimated as 5.19×10 19 and 13.38×10 19 m −2 , respectively, which are comparable to the previously reported values for Pt/LSMO bilayer films 97 .…”

“…7 depicts the LSMO thickness dependence of Gilbert coefficient α(t FM ) that shows an increasing trend with decrease in the film thickness signifying the delay in magnetization switching in TLs. The total magnetic relaxation of the TL is deduced from the relation α = α 0 +γ/(4πM s )( g ↑↓ /t FM ) 97 . Here, M s is the saturation magnetization, γ represents the gyromagnetic ratio, α 0 is the residual Gilbert constant and g ↑↓ represents spin mixing conductance.…”

Pure spin current manipulation in antiferromagnetically exchange coupled heterostructures

“…where J c and J s are the charge current and the pumped spin current, respectively, and r is the polarization direction of the pure spin current. Recent works in this field combine non-conventional components for the exploitation of these effects such as manganites 17,18 or magnetoelectric structures combined with strong SOC metals that can be used to modify the magnetic field position at which the spin pumping phenomenon occurs. 19 The interplay between materials with different properties and metallic layers with strong SOC can lead to the design of new hybrid spintronic devices with improved performance.…”

Simultaneous observation of anti-damping and inverse spin Hall effect in La$_{0.67}$Sr$_{0.33}$MnO$_{3}$/Pt bilayer system

“…There are a few reports where spin pumping has been investigated in LSMO/Pt bilayers for which the LSMO is primarily prepared by pulsed laser deposition technique. [22][23][24][25][26][27] In this work, we aim to study LSMO/Pt bilayers where the samples have been fabricated by oxide molecular beam epitaxy (OMBE) technique. In recent years OMBE has been proven to be an excellent technique to grow high qualilty complex oxide thin films.…”