Transition Metal Dichalcogenide 1T$'$-MoTe$_2$ Nanoscale Films as Spin Pumping Platforms

TL;DR

This study demonstrates that chemically grown 1T' phase MoTe2 thin films can effectively induce spin-charge conversion in heterostructures, showing promise for spintronic device applications due to their high spin Hall angle and spin-mixing conductance.

Contribution

It provides the first detailed measurement of spin-pumping and spin-charge conversion efficiency in 1T'-MoTe2 thin films at room temperature, highlighting their potential as a spintronic material.

Findings

Spin-mixing conductance up to ~1.6 x 10^20 m^-2

Spin Hall angle of 1.7% in MoTe2 films

Effective spin-charge conversion comparable to heavy metals

Abstract

Transition metal dichalcogenides (TMDs) have emerged as a promising class of materials for spintronics, with the aim of promoting efficient spin-charge conversion (SCC) in TMD/ferromagnet (FM)-based devices. The MoTe$_2$ semimetal with distorted orthorhombic crystal structure in the 1T$'$ phase has gathered particular attention due to its high spin-orbit coupling and reconfigurability as a type-II Weyl semimetal close to room temperature. Here, we report on the role of chemically grown 1T$'$-MoTe$_2$ thin films in inducing SCC in 1T$'$-MoTe$_2$/FM heterostructures as measured at room temperature. Ferromagnetic resonance (FMR) and electrically detected spin-pumping FMR measurements performed on 1T$'$-MoTe$_2$/Co/Au and 1T$'$-MoTe$_2$/Au/Co/Au heterostructures reveal a spin-mixing conductance value of up to $\sim1.6 \times 10^{20}~\mathrm{m^{-2}}$ and a spin Hall angle of $1.7\%$. These findings position MoTe$_2$ thin films as a competitive spin-charge conversion option compared to other functional materials (e.g., heavy metals, topological insulators), highlighting their potential for future applications in spintronic devices.