Defect and electronic structures in TiSi2 thin films produced by co-sputtering part 1:: Defect analysis by transmission electron microscopy

Phase transformation and defect structures in thin-film TiSi2 produced by co-sputtering have been investigated as a function of annealing temperature by transmission electron microscopy. Metastable C49 crystallites nucleate first in the amorphous matrix from as low as 100 degreesC. This is due to the lower surface energy of C49 crystallites arising from the similarity in electronic structure, chemical bonding and atomic density between the C49 and amorphous modifications. All C49 crystallites contain numerous (010) faults, which are boundaries between two differently oriented domains related to each other by a 90 degrees rotation about [010]. Stable C54 crystallites nucleate in the C49 matrix above 700 degreesC and most C54 crystallites contain twins with the twin habit plane parallel to (001), which is perpendicular to the (110) twinning plane. Ternary additions to TiSi2 thin films to reduce the C49-->C54 transformation temperature are discussed on the basis of the results from electron energy-loss spectroscopy (EELS) analyses described in the companion paper. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.