Reaction-diffusion-induced explosive crystallization in a metal–selenium nanometer film structure

Abstract

Experimental data for reaction-diffusion-induced explosive crystallization in a nanodimensional metal (Cu, Ag)/selenium structure are presented. It is found that after the metal layer has completely diffused into the amorphous Se film, the electrical potential rises from 0.14 to 1.21 V in the Cu(30 nm)/Se(140 nm) heterolayer and from 0.01 to 1.17 V in the Ag(30 nm)/Se(140 nm) heterolayer. The metals diffusing into the amorphous Se layer interact with Se, forming nuclei of a new phase (CuSe or Ag₂Se). The intense growth of the CuSe and Ag₂Se crystallization centers results in a considerable liberation of latent energy in the form of phase transformation heat and in explosive growth of CuSe and Ag₂Se nanocrystalline particles. The mean size of CuSe and Ag₂Se crystallites equals 25 and 50 nm, respectively.