T. Kizuka et al., GROWTH OF FINE CRYSTALS WITH A-15 TYPE-STRUCTURE IN VACUUM-DEPOSITED TUNGSTEN FILMS STUDIED BY HIGH-RESOLUTION ELECTRON-MICROSCOPY, Journal of crystal growth, 131(3-4), 1993, pp. 439-447
High-resolution electron microscopy was performed on fine crystals wit
h A-15 type structure prepared by vacuum-deposition of tungsten. The s
ize distribution of the crystals with the A- 15 type structure was ran
ged from 2 to 11 nm and was similar to that of the bcc type structure
coexisting in the film, indicating that the nucleation of both structu
res generated at the same time in the initial stage of growth. The cri
tical grain size of transformation from bcc to A-15 type structure was
not observed in the nanometer-sized region. Coalescence of the nanome
ter-sized crystals with A-15 type structure was observed in the film.
It was found that the crystals were connected by stacking faults with
displacement vector of 1/2[100] and nanometer-sized tilt grain boundar
ies rotated by 30-degrees around the [100]A-15 axis. It was also impli
ed from the observation that the A-15 structure in the present film wa
s stabilized by some kinds of lattice defects.