Inverse Spin-Hall Effect Induced by Spin Pumping in Different Thickness Pt Films

Abstract

The inverse spin-Hall effect, conversion of spin currents into electromotive force, has been investigated in Pt thin films with changing the thickness of the Pt films. We measured the electric voltage due to the inverse spin-Hall effect induced by the spin pumping in Ni <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">81</sub> Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">19</sub> /Pt bilayer systems with different Pt thickness films ( <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</sub> =10, 30, 50, and 75 nm) at room temperature. The experimental results show that the signal induced by the inverse spin-Hall effect <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ISHE</sub> is inversely proportional to the Pt thickness <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</sub> , which is well reproduced by a simple equivalent circuit model.