Amorphous alloy of Se90In9.3Cu0.7 has been prepared by the usual melt-quench technique under vacuum. Data from differential thermal analysis (DTA) at various heating rates and x-ray analysis of this alloy were investigated and reported. The activation energies of glass transition, E-g, and crystallization transition, E-c, were evaluated from the dependence of the glass temperature T-g and the crystallization temperature T-c on the heating rate. The crystalline phases resulting from DTA were identified using x-ray diffraction. The results reveal that the prepared alloy is structurally heterogeneous at a molecular level, in which In6Se7, Cu5Se4, and Cu2Se dispersed in Se-Se matrix. (c) 2006 American Vacuum Society.