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Quantitative Auger electron analysis of titanium nitrides
A4 Surface Science 149 (1985) 93-104 North-Holland, Amsterdam
93
ANALYSIS OF SURFACE BOND LENGTHS REPORTED FOR CHEMISORPTION ON METAL SURFACES K.A.R. MITCHELL Division of Chemistry Canada KIA OR9 Received
* National
Research
Council of Canada,
Montreal
Road, Ottawa,
Ontario,
19 June 1984
A review is given of bond length information available from the techniques of surface crystallography (particularly with LEED, SEXAFS and photoelectron diffraction) for chemisorption on well-defined surfaces of metals (M). For adsorbed main-group atoms (X), measured X-M interatomic distances for 38 combinations of X and M have been assessed with a bond order-bond length relation in combination with the Schomaker-Stevenson approach for determining singlebond lengths. When the surface bond orders are fixed primarily by the valency of X, this approach appears to provide a simple framework for predicing X-M surface bond lengths. Further, in cases where agreement has been reached from different surface crystallographic techniques, this framework has the potential for assessing refinements to the surface bonding model (e.g. in determining the roles of the effective surface valency of M, and of coordinate bonding and supplementary n bonding between X and M). Preliminary comparisons of structural data are also given for molecular adsorption (CO and ethylidyne) and for the chemisorption of other metal atoms.
Surface Science 149 (1985) 105-118 North-Holland, Amsterdam
QUANTITATIVE NITRIDES
AUGER ELECTRON
105
ANALYSIS
OF TITANIUM
P.T. DAWSON and K.K. TZATZOV * Chemistry Department and Institute for Materials Research, MeMaster Canada L.8S 4Ml Received
University, Hamilton, Ontario,
6 June 1984
Chemical analysis of titanium nitrides by Auger Electron Spectroscopy is complicated by the fact that the main Auger electron emission from nitrogen occurs at an energy that completely overlaps the transition from titanium. For this reason, most surface analysis of titanium nitride has been semiquantitative, at best. In this paper, Auger spectrum simulation techniques are used to establish that satisfactory accuracy can be attained in the determination of nitrogen to titanium ratios. The relative sensitivity correction factors for nitrogen and titanium matrix effects are calculated and shown to be essentially unity. Relative sensitivity factors are determined using standards and also using an internal calibration technique. Compositions determined by these several methods are compared for ion-implanted nitride films. The technique is also applied to the analysis of a depth profile through a nitride film grown by reaction of Ti with NH, and characterised by X-ray diffraction.
93
ANALYSIS OF SURFACE BOND LENGTHS REPORTED FOR CHEMISORPTION ON METAL SURFACES K.A.R. MITCHELL Division of Chemistry Canada KIA OR9 Received
* National
Research
Council of Canada,
Montreal
Road, Ottawa,
Ontario,
19 June 1984
A review is given of bond length information available from the techniques of surface crystallography (particularly with LEED, SEXAFS and photoelectron diffraction) for chemisorption on well-defined surfaces of metals (M). For adsorbed main-group atoms (X), measured X-M interatomic distances for 38 combinations of X and M have been assessed with a bond order-bond length relation in combination with the Schomaker-Stevenson approach for determining singlebond lengths. When the surface bond orders are fixed primarily by the valency of X, this approach appears to provide a simple framework for predicing X-M surface bond lengths. Further, in cases where agreement has been reached from different surface crystallographic techniques, this framework has the potential for assessing refinements to the surface bonding model (e.g. in determining the roles of the effective surface valency of M, and of coordinate bonding and supplementary n bonding between X and M). Preliminary comparisons of structural data are also given for molecular adsorption (CO and ethylidyne) and for the chemisorption of other metal atoms.
Surface Science 149 (1985) 105-118 North-Holland, Amsterdam
QUANTITATIVE NITRIDES
AUGER ELECTRON
105
ANALYSIS
OF TITANIUM
P.T. DAWSON and K.K. TZATZOV * Chemistry Department and Institute for Materials Research, MeMaster Canada L.8S 4Ml Received
University, Hamilton, Ontario,
6 June 1984
Chemical analysis of titanium nitrides by Auger Electron Spectroscopy is complicated by the fact that the main Auger electron emission from nitrogen occurs at an energy that completely overlaps the transition from titanium. For this reason, most surface analysis of titanium nitride has been semiquantitative, at best. In this paper, Auger spectrum simulation techniques are used to establish that satisfactory accuracy can be attained in the determination of nitrogen to titanium ratios. The relative sensitivity correction factors for nitrogen and titanium matrix effects are calculated and shown to be essentially unity. Relative sensitivity factors are determined using standards and also using an internal calibration technique. Compositions determined by these several methods are compared for ion-implanted nitride films. The technique is also applied to the analysis of a depth profile through a nitride film grown by reaction of Ti with NH, and characterised by X-ray diffraction.