Nanocrystallization through phase separation in binary alloy films

Thin Sb-Se films with compositions ranging between 70 and 80 at% Sb were de posited onto glass substrates. During and/or immediately after deposition p hase separation occurs. The observed characteristic wavelength of spinodal decomposition in these films was between 10 and 20nm. The formation of nano crystals, predominantly Sb nanocrystals, is induced by annealing at tempera tures ranging from 120 to 200 degrees C. Using XRD and TEM the crystal grai n size and microstructure development were elaborated. The estimated mean c rystal grain sizes were between 12 and 20 nm depending on crystal orientati on and film thickness. Using non-isothermal DSC measurements thermodynamic and kinetic parameters of nanocrystallization were obtained. The estimated enthalpies of crystallization, activation energies and peak crystallization temperatures depend on both film composition and thickness. Crystallizatio n by nucleation and growth mechanism and crystal growth from crystal cluste rs, developed immediately after the phase separation, were observed in thes e nanocrystalline films. (C) 2000 Elsevier Science Ltd. All rights reserved .