Magnetic anisotropy of crystalline Fe films grown on (001) GaAs substrates using Ge buffer layers

Seul-Ki Bac,J K Furdyna,Hakjoon Lee,Taehee Yoo,Sanghoon Lee,Sangyeop Lee,Seonghoon Choi,X Liu

doi:10.1063/1.4942949

Seul-Ki Bac, J K Furdyna + Show 6 more

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https://doi.org/10.1063/1.4942949

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Journal: AIP Advances	Publication Date: Feb 23, 2016
Citations: 1	License type: CC BY 3.0

Affiliation: Korea University, University of Notre Dame

Abstract

Magnetic anisotropy of Fe films grown on (001) GaAs substrates using Ge buffer layers were investigated by planar Hall effect measurements. In addition to phenomena arising from dominant cubic symmetry of the Fe specimen, the study of angular dependence of magnetization reversal revealed breaking of this symmetry in the form of systematic asymmetric shifts of magnetic hysteresis loops around the &lt;110 &gt; crystallographic directions. We ascribe such symmetry breaking to an admixture of uniaxial anisotropy associated with the [100] direction in the Fe film. To determine the parameters associated with this uniaxial anisotropy, we quantitatively analyze the asymmetric shifts of the hysteresis loop centers from the &lt;110 &gt; directions. Even though the value of these parameters turns out to be relatively small compared to that of the cubic anisotropy (by about two orders of magnitude), they survive up to room temperature.

Highlights

Magnetic anisotropy is a critically important property of ferromagnetic films, since it determines their easy magnetization directions
Systematic study of magnetization reversal was carried out on crystalline Fe film grown on Ge buffers using planar Hall resistance (PHR) measurements
The two-step switching behavior of PHR during magnetization reversal reveals the presence of the four magnetic easy axes in the film plane, indicating the dominance of the < 100 > cubic anisotropy in Fe films

Summary

INTRODUCTION

Magnetic anisotropy is a critically important property of ferromagnetic films, since it determines their easy magnetization directions. In the case of crystalline Fe films, a cubic magnetic anisotropy along the crystallographic < 100 > directions and an uniaxial anisotropy along one of the < 110 > directions are normally observed when the film is epitaxially grown on such substrates as (001) GaAs.. It is generally accepted that the former property originates from the cubic crystal structure of Fe, and the latter is related to surface reconstruction of the substrate during film growth, which determines the specific bond alignments symmetry on the surface on which the Fe atoms are epitaxially deposited..

RESULTS AND DISCUSSION

CW H and CC H

SUMMARY