Vibrational spectroscopy study of the structure of silicalite-1 films on agold surface

The structure of silicalite-l films grown on seeded gold surfaces is invest igated by modelling the observed changes in the infrared reflection absorpt ion (IRRA) spectra of samples treated for different times in the synthesis solution. The results show that a gradual deformation of the five-membered silicon-oxygen rings occurs during the first 11 h of the hydrothermal treat ment which leads to breaking of Si-O-Si linkages and to formation of linear defects along the c-axis. Interactions between the dislocations and the gr ain boundaries during the further growth of the film provoke the appearance of void spaces in the grain boundary interface which may cause incipient c racking in the silicalite-l films on seeded gold surfaces. The range 1000-1 300 cm(-1) in the IRRA spectra is found to be appropriate for estimating th e quality of silicalite-l films grown on metal surfaces. (C) 1999 Elsevier Science B.V. All rights reserved.