Author(s): Xu, YH (Xu, Yaohan); Tong, SC (Tong, Shucheng); Lu, J (Lu, Jun); Wei, DH (Wei, Dahai); Zhao, JH (Zhao, Jianhua)
Source: APPLIED PHYSICS LETTERS Volume: 118 Issue: 25 Article Number: 252405 DOI: 10.1063/5.0053430 Published: JUN 21 2021
Abstract: Compensated ferrimagnetic materials such as Co-Tb and Co-Gd have been confirmed to have significant spin-orbit torque (SOT) efficiency. However, the large coercivity and a relatively small spin-mixing conductance may hinder the applications of the near compensated ferrimagnets. In this work, we investigate the SOT effect and its potential applications in Ta/Co-Tb/Pt heterostructures. Based on a Co-rich ferrimagnetic alloy, we obtain a significant SOT switching efficiency of 15 +/- 1 (10(-6)Oe cm(2)/A) and a considerable effective spin Hall angle of theta(eff) = 0:270 +/- 0:005. Using harmonic Hall measurement, the temperature dependence of the damping-like effective field has been extracted. The SOT efficiency scales linearly with 1/Ms in the high-temperature range but significantly deviates from this linear scaling law at a lower temperature, which is near the compensation point. In the Tb rich Ta/Co-Tb/Pt SOT device, we demonstrate the functionality of a neuron and the dependence of firing possibility on the intensity of coming stimulus, which is mimicked by the SOT switching dynamics in the ferrimagnetic Co-Tb alloy. Published under an exclusive license by AIP Publishing.
Accession Number: WOS:000692013700001
ISSN: 0003-6951
eISSN: 1077-3118