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Thermal stability of magnetoresistive materials
van Driel, J.
Publication date
1999
Link to publication
Citation for published version (APA):
van Driel, J. (1999). Thermal stability of magnetoresistive materials. Universiteit van
Amsterdam.
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Contents
General introduction 1
1.1 Introduction 1 1.2 Magnetoresistance in intermetallic compounds 3
1.3 The exchange-biased spin valve 4 1.4 The giant magnetoresistance effect and the two-current model 5
1.5 Exchange-biasing interaction 7
1.6 Outline of the thesis 9
Compositional dependence of the giant magnetoresistance in F exR h i _x
thin films 11
2.1 Introduction 11 2.2 Experimental procedure 13
2.3 Experimental results 14 2.3.1 Crystal and grain structure before and after the annealing
treat-ment 14 2.3.2 Influence of annealing temperature and time on the magnetic
properties 17 2.3.3 Mössbauer spectroscopy 18
2.3.4 Saturation magnetization 22 2.3.5 Magnetization and magnetoresistance measurements 23
2.4 Discussion 24 2.4.1 Compositional dependence of phases observed 24
2.4.2 Stress 25 2.4.3 Dependence of the magnetic transition on composition 25
2.4.4 Effect on the magnetic transition of strain and microstructure . 28
2.4.5 Magnetoresistance ratio 28
2.5 Conclusions 30
Magnetic linear dichroism of infrared light in ferromagnetic alloy
films 33
3.1 Introduction 33 3.2 Refraction of light in a thin metallic film 34
3.3 Experimental set-up 37 3.4 Experimental results 39
vi Contents
3.5 Model of the linear-dichroism effect 41 3.6 Analysis of the experimental results 45
3.7 Conclusions 48
4 Magnetorefractive and magnetic-linear-dichroism effect in
exchange-biased spin valves 51
4.1 Introduction 51 4.2 Experimental set-up 52
4.3 Experimental results 54 4.4 Model and discussion 56
4.5 Conclusions 61
5 Thermal stability of IrigMn8i as exchange-biasing material 63
5.1 Introduction 63 5.2 Experimental set-up 64
5.3 Experimental results 65
5.4 Discussion 73 5.4.1 Top/ bottom configuration 73
5.4.2 Microstructural influence on the exchange-biasing interaction . 74
5.4.3 Exchange biasing as a function of AF-layer thickness 75 5.4.4 Blocking temperature as a function of IrigMn8i-layer thickness 77
5.5 Conclusions 78
6 Relaxation of the exchange-biasing interaction for I r i9M n8i / Ni8oFe2o
and I r i g M n s i / C o9 0F e i0 bilayers 81
6.1 Introduction 81 6.2 Overview of theoretical models 82
6.3 Experimental set-up 86 6.4 Experimental results and discussion 87
6.5 Summary and conclusions 94
References 97 Summary 103 Samenvatting 107 List of publications 111 Curriculum vitae 113 Dankwoord 115
