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Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
Extrinsic spin Hall effect induced by iridium impurities in copper
1Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwa-no-ha, Kashiwa, Chiba 277-8581, Japan. niimi@issp.u-tokyo.ac.jp
Physical Review Letters
|April 27, 2011
Summary
The extrinsic spin Hall effect in copper-iridium (CuIr) alloys is driven by iridium impurities. Spin Hall resistivity increases with impurity concentration, showing a clear example of skew scattering in nonmagnetic alloys.
Area of Science:
- Condensed matter physics
- Materials science
- Spintronics
Background:
- The spin Hall effect (SHE) is a phenomenon where a spin current is generated transverse to an electric current in a material.
- Understanding the mechanisms, particularly extrinsic contributions like skew scattering, is crucial for spintronic device applications.
- Nonmagnetic alloys offer a platform to study these effects without ferromagnetic ordering.
Purpose of the Study:
- To investigate the extrinsic spin Hall effect in copper-iridium (CuIr) alloys.
- To quantify the influence of iridium (Ir) impurity concentration on the spin Hall effect.
- To determine the dominant scattering mechanism contributing to the observed spin Hall effect.
Main Methods:
- Fabrication of CuIr wires with varying Ir impurity concentrations.
- Injection of a pure spin current using a lateral spin valve structure.
- Measurement of spin Hall resistivity and spin Hall angle as a function of Ir concentration and temperature.
Main Results:
- No spin Hall effect was observed in pure copper (Cu) without Ir impurities.
- Spin Hall resistivity of CuIr increased linearly with increasing Ir impurity concentration.
- The spin Hall angle of CuIr remained constant at (2.1±0.6)% across the studied concentration range (1%-12%) and was largely temperature-independent.
Conclusions:
- Iridium impurities are the primary source of the extrinsic spin Hall effect in CuIr alloys.
- Skew scattering is identified as the predominant mechanism responsible for the observed spin Hall effect.
- The findings highlight the potential of nonmagnetic alloys for tunable spintronic functionalities.
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