MODERN TECHNIQUES OF SURFACE SCIENCE

Transcription

1 MODERN TECHNIQUES OF SURFACE SCIENCE Second edition D. P. WOODRUFF & T. A. DELCHAR Department ofphysics, University of Warwick CAMBRIDGE UNIVERSITY PRESS

2 Contents Preface to first edition Preface to second edition Abbreviations page xiii xv xvii 1 Introduction Why surfaces? Ultra-High-Vacuum (UHV), contamination and cleaning Adsorption at surfaces Surface analytical techniques 11 2 Surface crystallography and diffraction Surface symmetry Description of overlayer structures Reciprocal net and electron diffraction Electron diffraction - qualitative consideration Domains, Steps and defects Surface structure determination using LEED General considerations and the failure of Single scattering and Fourier transform methods Basic elements of multiple scattering theories Application of multiple scattering calculations Thermal effects Reflection High Energy Electron Diffraction (RHEED) X-ray methods of surface structure determination Introduction Grazing incidence refraction of X-rays at surfaces Measuring the diffraction pattern Crystal truncation rods 85 vu

3 Vlll Contents Applications of surface X-ray diffraction X-ray Standing waves 97 Further reading 104 Electron spectroscopies General considerations Introduction Electron attenuation lengths and surface specificity Electron energy spectrometers Electron energy distributions in electron spectroscopies Electron spectroscopies: core level spectroscopies X-ray Photoelectron Spectroscopy (XPS) Introduction Photon sources Shapes and shifts XPS as a core level spectroscopy Synchrotron radiation studies Structural effects in XPS Auger electron spectroscopy (AES) Introduction - basic processes Energy levels, shifts and shapes AES for surface composition analysis Structural effects in AES AES versus XPS - some comparisons Threshold techniques Appearance Potential Spectroscopy (APS) Ionisation Loss Spectroscopy (ILS) Structural effects in threshold spectroscopies Ultraviolet Photoelectron Spectroscopy (UPS) Introduction UPS in the elucidation of band structure UPS in the study of adsorbed molecules Inverse photoemission Introduction Photoemission and inverse photoemission - basic theory Experimental methods in inverse photoemission Applications of IPES and KRIPES 256 Further reading 264

4 Contents Incident ion techniques Introduction Charge exchange between ions and surfaces Ion Neutralisation Spectroscopy (INS) INS with metastable intermediates Experimental arrangements for INS Experimental results from neutralisation at metal surfaces Information from INS of metals Ion scattering techniques LEIS: basic principles Structural effects in LEIS Instrumentation, problems and prospects: LEIS Medium and High Energy Ion Scattering (MEIS and HEIS) Sputtering and depth profiling Secondary Ion Mass Spectrometry (SIMS) 338 Further reading 354 Desorption spectroscopies Introduction Thermal desorption techniques Introduction Qualitative analysis of pressure-time curves Experimental arrangements for flash desorption and TPD Flash desorption and TPD spectra Electronically stimulated desorption Basic mechanisms Mechanisms for physisorbed layers ESDIAD (ESD Ion Angular Distributions) Instrumentation and measurements Some applications and results 404 Further reading 409 Tunnclling microscopy Field emission The field emission microscope Factors governing Operation Practical microscope configurations 418 ix

5 X Contents Experimental results from Field Emission Microscopy (FEM) Field ionisation Field adsorption and field-induced chemisorption Field evaporation and desorption The field ion microscope The atom probe field ion microscope Electron Stimulated Field Desorption (ESFD) Scanning tunnelling microscopy Scanning Tunnelling Spectroscopy (STS) The Scanning Tunnelling Microscope (STM) Other applications of the STM The Atomic Force Microscope (AFM) 459 Further reading 460 Work function techniques Introduction Single crystal surfaces Polycrystalline surfaces Work function measurements based upon the diode method Work function measurements based on CPD Field emission measurements Phötoelectric measurements Experimental results 481 Further reading 484 Atomic and molecular beam scattering Introduction The beam-surface interaction Inelastic scattering, the classical view Inelastic scattering, the quantum mechanical view Elastic scattering Quantum versus classical formulation Scattering cross-section for diffuse scattering The production and use of molecular beams Detectors Experimental arrangements Scattering studies 513 Further reading 531

6 Contents 9 Vibrational spectroscopies Introduction IRAS Vibrational linewidths Electron Energy Loss Spectroscopy (EELS) Experimental methods in IRAS Applications of IRAS Breakdown of the relationship between adsorbate site and vibrational frequency Experimental methods in HREELS Experimental results from HREELS 557 Further reading 562 References 563 Index 576 xi