Title

Study on spin transport and spin dissipation in epitaxial Cr/Fe bilayer

Alternative Title

에피성장된 Cr/Fe 이중층 구조에서의 스핀 수송 현상 및 스핀 소산 연구

DGIST Authors

Nguyen Thi Thanh Huong ; Jung-Il Hong ; Sanghoon Kim

Advisor

홍정일

Co-Advisor(s)

Sanghoon Kim

Issued Date

2023

Awarded Date

2023-08-01

Citation

Nguyen Thi Thanh Huong. (2023). Study on spin transport and spin dissipation in epitaxial Cr/Fe bilayer. doi: 10.22677/THESIS.200000688393

Type

Thesis

Description

Epitaxial Cr/Fe bilayer; Unidirectional spin Hall magnetoresistance; electron-magnon scattering; magnetic damping

Table Of Contents

Ⅰ. Introduction 1
Overview of magnonics 1
II. Theoretical perspectives 4
2.1 Magnon 4
2.1.1 Zero spin wave 4
2.1.2 Magnon 8
2.2 Spin Hall effect and Orbital Hall effect 10
2.2.1 Spin Hall effect 11
2.2.2 Orbital Hall effect 13
2.3 Spin dissipation 14
2.3.1 Intrinsic damping 15
2.3.2 Extrinsic damping 17
2.3.3 Spin pumping damping 18
2.3 Magnetoresistance 20
2.3.1 Anisotropic magnetoresistance 20
2.3.2 Unidirectional spin Hall magnetoresistance 21
2.3.3 Spin Hall magnetoresistance 22
2.3.4 Magnon magnetoresistance 24
III. Experimental methods 26
3.1 Molecular beam epitaxy for epitaxial film growth 26
3.2 Unidirectional spin Hall MR: 2nd harmonic voltage measurement 28
3.3 Ferromagnetic resonance measurement 30
3.4 Photolithography & Ion milling 33
IV. Unidirectional spin Hall magnetoresistance in epitaxial Cr/Fe bilayer from electron-magnon scattering. 37
4.1 Introduction 37
4.2 Crystalline structure and magnetic properties 38
4.3 Magnetoresistance results 40
4.4 Discussion 47
4.5 Summary 49
V. Giant magnetic damping anisotropy in epitaxial Cr/Fe bilayer with the absence of magnetocrystalline anisotropy 50
5.1 Introduction 50
5.2 Crystalline structure and magnetic properties 51
5.3 Magnetic damping anisotropy 54
5.4 Discussion 57
5.5 Summary 61
VI. Conclusion and Outlook 62
6.1 Conclusion 62
6.2 Outlook 63
References 64

URI

http://hdl.handle.net/20.500.11750/46416
http://dgist.dcollection.net/common/orgView/200000688393

DOI

10.22677/THESIS.200000688393

Degree

Doctor

Department

Department of Physics and Chemistry

Publisher

DGIST

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