Effect of crystalline inclusions on the explosive crystallization of amorphous films of pure metals

The front velocity, U f, of the explosive crystallization (EC) of amorphous films of Yb and Bi was investigated as a function of relative volume, x, of crystalline inclusions. One-phase amorphous films with thicknesses between 40 and 70 nm were obtained by vapour deposition on liquid helium-cooled substrates. Partial crystallization of amorphous films was obtained by isothermal annealing. The EC of partially crystallized films was initiated by a local current pulse. The velocity of the EC front is found to diminish with growing x. At x ∼ 0.5, the EC ceases. Experimental results are quantitatively explained by a theory based on the approximation of the ‘renormalized’ temperature effect of crystalization T ̃ Q = (1 − x) T Q . Here T Q is the ‘initial’ (at x = 0) temperature effect of crystallization ( T Q = Q/ c, where Q is the crystallization heat and c is the specific heat). validity of the above approximation is discussed.