Strain-induced modulation of temperature characteristics in ferrimagnetic Tb\u2013Fe films

Shinya Ota,Pham Van Thach,Hiroyuki Awano,Kentaro Toyoki,Yoshinori Kotani,Akira Ando,Tetsuya Nakamura,Tomohiro Koyama,Daichi Chiba

doi:10.1038/s41598-021-85642-3

Abstract

This study investigates the effect of strain on the compensation temperature of ferrimagnetic Tb–Fe films formed on a flexible substrate. The compensation temperature is determined by the anomalous Hall measurement, and an application of 1.2% tensile strain reduces the compensation temperature by 12 K. X-ray magnetic circular dichroism reveals that approximately 5% of Fe magnetic moment and approximately 1% of Tb magnetic moment are reduced by an application of 0.9% tensile strain at the room temperature. To understand the greater reduction in Fe magnetization compared with that in Tb and the compensation temperature reduction simultaneously, a model applying molecular field theory is analyzed. Changes in three types of exchange coupling between Fe and Tb atoms are speculated to be caused by the strain.

Highlights

This study investigates the effect of strain on the compensation temperature of ferrimagnetic Tb–Fe films formed on a flexible substrate
To demonstrate that such a change can occur, we analyzed a toy model based on molecular field theory that can simulate the temperature dependence of RE–TM s ystems[13,14,15]
The temperature dependence of each magnetization is governed by the Brillouin function BJ(x): MFe(T) = MFe(0)B JFe [MFe(0)HFe(T)/nFekBT], (3)

Summary

Introduction

This study investigates the effect of strain on the compensation temperature of ferrimagnetic Tb–Fe films formed on a flexible substrate. A large magnetic anisotropy change has been observed by applying a %-order strain to a flexible substrate on which magnetic films is d eposited[1,2,3]. This is due to the inverse magnetostriction effect and the ability of metallic thin films on flexible-substrates[4] to tolerate such a large strain. An alloy of rare-earth (RE) and transition-metal (TM) elements with a large magnetostriction constant shows magnetic anisotropy change on the order of sub-Tesla[2]. We demonstrate that the Tcomp is changed by a strain application, accompanied by magnetic moment changes

Methods

Results

Conclusion