Microstructural study on the C49-to-C54 phase transformation in TiSi2 formed from preamorphization implantation

Microstructural characteristics of C49-TiSi2 in narrow lines have been inve stigated by transmission electron microscopy. The C49-TiSi2 formed by a pre amorphization treatment exhibits small grain size and heavily faulted struc tures. C54 grains are also observed sporadically in the C49 matrix in spite of relatively low temperature range. Moreover, defects circularly distribu te around a less-defective region in the vicinity of the C54 grains. The C4 9 grains in these regions are well aligned with identical crystallographic orientations. These results indicate two-dimensional growth of C49-TiSi2, a nd the circular defects are introduced by internal stress associated with t he growth process. Also the internal stress is considered to enhance the he terogeneous C54 nucleation. (C) 1999 American Institute of Physics. [S0021- 8979(99)02405-6].