Abstract
Table of Contents
1 Introduction 11
2 Surface characterization techniques 15
2.1 Photoelectron spectroscopy............................................................................................................. 15
2.2 Angle-resolved photoelectron spectroscopy..................................................................................... 19
2.3 X-ray photoclectron diffraction....................................................................................................... 22
2.4 X-ray absorption spectroscopy.......................................................................................................... 23
2.5 Experimental Setup ......................................................................................................................... 24
2.5.1 VG ESCALAB 220 UHVsystem......................................................................................... 24
2.5.2 SLIC end-station................................................................................................................... 25
3 UHV-grown Ga2Û3 on single crystallineCU2O surfaces 26
3.1 Introduction........................................................................................................................................ 26
3.2 Single crystalline Cu2O(lll) and(110) surfaces............................................................................. 27
3.2.1 Crystal structure of CU2O.................................................................................................... 27
3.2.2 Electronic structure of CU2O.............................................................................................. 30
3.3 Single crystalline Ga2Û3 surfaces.................................................................................................... 33
3.3.1 Crystal structure of Ga2C>3................................................................................................. 33
3.3.2 Electronic structure of Ga2C>3.............................................................................................. 35
3.3.3 Growth of crystalline Ga2Û3 .............................................................................................. 37
3.4 Sample preparation............................................................................................................................ 38
3.5 Ga+Ü2 deposition on Cu2O(lll) surfaces..................................................................................... 40
3.5.1 Postannealing effects and influence of the substrate termination........................................ 40
3.5.2 Energy band alignment at the interface............................................................................ 43
3.5.3 Reduction of Cu2O(lll) upon Ga2Û3 deposition............................................................. 46
3.5.4 Atomic structure of Ga2O3/Cu2O(lll) ............................................................................ 51
3.6 Ga deposition on Cu2O(lll) surfaces.............................................................................................. 52
3.7 Ga+O2 deposition on Cu2O(110) surfaces..................................................................................... 54
3.8 Conclusion ........................................................................................................................................ 58
4 Formation of NiIFe3_IO4 on Fe304(001) 60
4.1 Introduction........................................................................................................................................ 60
4.2 Experimental Details......................................................................................................................... 62
4.3 Computational Details...................................................................................................................... 63
4.4 Results and Discussion...................................................................................................................... 65
4.5 Conclusion ....................................................................................................................................... 76
4.6 Formation of NiIFc3_IO4 on Fc304(001): Supplementary Information .................................... 77
Surface electronic structure of Ni-doped FejO^OOl) 93
5.1 Introduction....................................................................................................................................... 93
5.2 Experimental Details........................................................................................................................ 95
5.3 Computational Details..................................................................................................................... 96
5.4 Results and Discussion........................................................ 97
5.4.1 Final-state scattering effects in Fe304(001) ...................................................................... 98
5.4.2 Occupied states of Ni/Fe304(001) ..................................................................................... 101
5.4.3 Unoccupied states of Ni/Fe304(001).................................................................................. 106
5.5 Conclusion .......................................................................................................................................... 110
5.6 Surface electronic structure of Ni-doped Fe304(001): Supplementary Information.....................112
Conclusion and outlook 123
Taskin, Mert