Spin–charge conversion in transition metal oxides

Abstract

The interaction between spin and charge degrees of freedom offers a powerful tool to manipulate magnetization in memories by the current induced spin–orbit torque. This novel phenomenon, conventionally existing in semiconductors and metallic systems, has recently been observed in transition metal oxides, exhibiting a surprising large spin-Hall angle. In this Perspective, we will review recent research progress in the spin–charge conversion in transition metal oxides, the remaining challenges, and new opportunities. We will first briefly summarize recent progress in the spin–charge conversion in representative transition metal oxides, including SrIrO3, SrRuO3, and IrO2, along with other materials predicted by calculations. Next, we will survey the possible candidate materials in the family of transition metal oxides. Recent advances in the growth of SrIrO3 films will be reviewed along with the implications on the study of the spin-Hall effect. We will also discuss other promising candidates that could serve as the spin source, including films of pyrochlore and delafossite oxides as well as oxide heterostructures.

Spin to charge conversion in chemically deposited epitaxial La0.9MnO3 thin films capped with Pt

“…In materials with large spin-orbit coupling, such as Pt, a pure spin current can be converted into a charge current, and vice versa, due to ISHE and spin Hall effect (SHE). 32 The effective detection of SP-induced ISHE voltage signal allows to circumvent the problem of interfacial spin decoherence with important implications in the quantification of crucial spintronic parameters such as the spin Hall angle or the spin diffusion length. [33][34][35] In SP experiments, the line shape of the measured voltage signals follows that of the FMR spectra, i.e., Lorentzian curve, therefore the measured voltage signal is given by the following expression:…”

Implementing Complex Oxides for Efficient Room‐Temperature Spin–Orbit Torque Switching

“…are found to exhibit moderate conductivity and relative large SOT efficiency as well as a dependence between the SOT efficiency and the crystal symmetry. [ 20–32 ] These features highlight the importance of implementing complex oxides for spin‐orbitronics.…”

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In the meanwhile, complex oxides are attracting growing attentions in the spintronics community, in which efficient spin-charge conversion has been revealed. [19][20][21][22][23][24][25][26][27][28][29][30][31] Due to the strong correlation between the lattice, charge, spin and orbital degrees of freedom, these complex oxides may exhibit unique advantages for promoting efficient spintronic devices. For example, complex oxides with 4d and 5d transition metal cations (SrRuO 3 , SrIrO 3 , IrO 2 , etc.)

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Recent development and challenges in fuel cells and water electrolyzer reactions: an overview

“…The spin-Hall angle, defined as the ratio of the spin current to the applied charge current | j s / j c |, is estimated to be in the range of 0.3–1.0, which is significantly greater than the spin-Hall angle in conventional heavy metals such as Pt/Co (0.013–0.13). 75 SrRuO 3 is a TMO having a structure similar to SrIrO 3 . Owing to the 4d element Ru, it has also generated interest in studying its SHE.…”