Whole powder pattern analysis of thin TiO2 layers
Z. Matěj, L. Nichtová and R. Kuel
Department of Electronic Structures, Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 121 16 Praha 2, Czech Republic
TiO2 nanopowders appear many special properties. In numerous practical applications only thin surface region is significant for desired product functionality and hence it is not surprising that also thin TiO2 films are a matter of interest. Investigated TiO2 layers were prepared by magnetron sputtering (ZČU Plzeň) and they consist from an amorphous component and two most common TiO2 crystalline phases: anatese and rutile. It is suspected that there is a surface anatase rich film on a rutile rich substrate layer. This hypothesis should be clarified by detailed x-ray diffraction study.
A computer program for whole powder patter
fitting of our samples was developed. It is based on a crystallographic
computing library ObjCryst++ (a program Fox) [1]
which is in the program used for structure factors and whole powder pattern
calculations. Library fitting algorithms are employed there as well. Intensity
corrections for the parallel beam geometry accounting for absorption in the
layered structure of the samples, simple texture description, background correction
and microstructural models [2,3]
for profile shape evaluation were mixed in the program to simulate measured
data.
1. V. Favre-Nicolin, R. Černý, J. Appl. Cryst., 35 (2002) 734-743.
2. P. Scardi, M. Leoni, Acta Cryst. A, 58 (2002) 190-200.
3. G. Ribárik , T. Ungár, J. Gubicza, J. Appl. Crys., 34 (2001) 669-676.
Acknowledgements.
We would like to express our thanks to V. Fafre-Nicolin and teams of T. Ungár and P. Scardi
for opportunity of using and testing their computer programs.
This work is a part of the research plan MSM 0021620834 that is financed by the Ministry of Education of the Czech Republic.