# Spin mediated magneto-electro-thermal transport behavior in   Ni80Fe20/MgO/p-Si thin films

**Authors:** P. C. Lou, W. P. Beyermann, S. Kumar

arXiv: 1701.07854 · 2017-09-27

## TL;DR

This study demonstrates that spin accumulation, induced by the spin-Hall effect, significantly influences electro-thermal transport in Ni80Fe20/MgO/p-Si thin films, revealing new insights into spin-mediated behavior in semiconductors.

## Contribution

First experimental evidence of spin accumulation affecting electro-thermal transport in p-Si via the spin-Hall effect, highlighting a novel spin-mediated transport mechanism.

## Key findings

- Spin accumulation alters phononic thermal transport in p-Si.
- Inverted magnetoresistance switching observed at low temperatures.
- Anomalous Hall resistance decreases with increasing current.

## Abstract

In Si, spin-phonon interaction is the primary spin relaxation mechanism. At low temperatures, the absence of spin-phonon relaxation will lead to enhanced spin accumulation. Spin accumulation may change the electro-thermal transport within the material, and thus may serve as an investigative tool for characterizing spin-mediated behavior. Here we present the first experimental proof of spin accumulation induced electro-thermal transport behavior in a Pd (1 nm)/Ni80Fe20 (25 nm)/MgO (1 nm)/p-Si (2 um) specimen. The spin accumulation originates from the spin-Hall effect. The spin accumulation changes the phononic thermal transport in p-Si causing the observed magneto-electro-thermal transport behavior. We also observe the inverted switching behavior in magnetoresistance measurement at low temperatures in contrast to magnetic characterization, which is attributed to the canted spin states in p-Si due to spin accumulation. The spin accumulation is elucidated by current dependent anomalous Hall resistance measurement, which shows a decrease as the electric current is increased. This result may open a new paradigm in the field of spin-mediated transport behavior in semiconductor and semiconductor spintronics.

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Source: https://tomesphere.com/paper/1701.07854