In-plane magnetic field effect on switching voltage and thermal stability in electric-field-controlled perpendicular magnetic tunnel junctions

C Grezes,X Cai,J Langer,A Rojas Rozas,K L Wang,J G Alzate,P Khalili Amiri,F Ebrahimi,J A Katine,B Ocker

doi:10.1063/1.4959593

Abstract

The effect of in-plane magnetic field on switching voltage (Vsw) and thermal stability factor (Δ) are investigated in electric-field-controlled perpendicular magnetic tunnel junctions (p-MTJs). Dwell time measurements are used to determine the voltage dependence of the energy barrier height for various in-plane magnetic fields (Hin), and gain insight into the Hin dependent energy landscape. We find that both Vsw and Δ decrease with increasing Hin, with a dominant linear dependence. The results are reproduced by calculations based on a macrospin model while accounting for the modified magnetization configuration in the presence of an external magnetic field.

Highlights

Nanosecond bidirectional magnetization switching by the application of unipolar voltage pulses has been demonstrated,[1,2,3,4] and switching energy down to 6fJ/bit has been achieved in voltage-controlled magnetic anisotropy (VCMA)-controlled CoFeB/MgO magnetic tunnel junctions with perpendicular anisotropy (p-Magnetic tunnel junctions (MTJs)).[11]
The modification of the energy landscape affects the relevant parameters of the MTJs, including: (1) the thermal stability (∆ = Energy barrier heights (Eb)/kBT, where Eb denotes the energy barrier that separates the two magnetization states, kB is the Boltzmann constant, and T is the temperature), which characterizes the ability of the magnetization states to remain stable against thermal fluctuations, (2) the switching voltage (Vsw), which corresponds to the voltage required to switch between the two magnetization configurations, and (3) the switching time, equal to half the precession period
The effect of in-plane magnetic field on the period of the magnetization precession was studied in perpendicular magnetic tunnel junctions (p-MTJs).[12,13]

Summary

Introduction

In-plane magnetic field effect on switching voltage and thermal stability in electric-field-controlled perpendicular magnetic tunnel junctions The effect of in-plane magnetic field on switching voltage (Vsw) and thermal stability factor (∆) are investigated in electric-field-controlled perpendicular magnetic tunnel junctions (p-MTJs).

Results

Conclusion