Title

Lateral symmetry breaking for spin-orbit torque induced field-free switching using miscut sapphire substrate

Alternative Title

미스컷 사파이어 기판을 사용하여 스핀 궤도 토크 기반의 무자기장 스위칭을 위한 수평 대칭 깨짐 유도

DGIST Authors

Chun-Yeol You ; Jung-Il Hong ; Jin-A Kim

Advisor

유천열

Co-Advisor(s)

Jung-Il Hong

Issued Date

2022

Awarded Date

2022/02

Citation

Jin-A Kim. (2022). Lateral symmetry breaking for spin-orbit torque induced field-free switching using miscut sapphire substrate. doi: 10.22677/thesis.200000596416

Type

Thesis

Subject

Spin-orbit torque, field-free switching, symmetry breaking, miscut

Description

Spin-orbit torque, field-free switching, symmetry breaking, miscut

Table Of Contents

I. INTRODUCTION 1
II. THEORETICAL BACKGROUND 3
2.1 Spin-orbit Torque (SOT) 3
2.2 Spin-transfer torque (STT) and Spin-orbit torque (SOT) based magnetization switching 5
2.3 Field-free Spin-orbit Torque Switching 6
2.4 Sapphire Miscut Substrate 8
2.5 Magnetic Anisotropy 9
2.5.1 Shape Anisotropy (Demagnetization) 10
2.5.2 Magnetocrystalline Anisotropy 11
2.5.3 Zeeman energy 11
III. MATERIALS & METHODS 14
3.1 Film deposition and patterning 15
3.1.1 Magnetron Sputtering 16
3.1.2 Photolithography 17
3.1.3 Etching 20
3.2 Magnetic Property Measurement 21
3.2.1 Vibrational Sample Magnetometer (VSM) 21
3.2.2 Anomalous Hall effect (AHE) Magnetometry 22
3.2.3 Generalized Sucksmith-Tompson (GST) method 26
3.2.4 Separation of AHE and Planar Hall effect(PHE) 27
3.3 SOT measurement 28
3.3.1 Harmonic Hall voltage measurement 29
3.3.2 Current Induced Magnetization Switching 30
IV. RESULTS & DISCUSSION 32
4.1 Substrate Surface Evaluation 32
4.2 Magnetic properties 35
4.3 Additional In-plane Magnetic Anisotropy by Miscut Sapphire Substrate 37
4.4 Current Induced Magnetization Switching by SOT 40
4.5 Field-free Switching by SOT 46
V. CONCLUSION 49

URI

http://dgist.dcollection.net/common/orgView/200000596416
http://hdl.handle.net/20.500.11750/16300

DOI

10.22677/thesis.200000596416

Degree

Master

Department

Emerging Materials Science

Publisher

DGIST

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