Crystallization kinetics of amorphous NiTi shape memory alloy thin films

The temperature dependence of the crystallite nucleation and growth rates is measured for amorphous NiTi thin films. Using transmission electron microscopy, crystallites are shown to nucleate homogeneously in the film and to grow in a channeling mode. A mechanism that suppresses heterogeneous nucleation is proposed. By manipulating nucleation and growth rates, grains as large as 60 μm can be obtained in submicron films.