Phase decomposition and nanocrystallization in amorphous Ni70Mo10P20 alloy

The structure of amorphous Ni70Mo10P20 alloy was studied by X-ray diffracti on and transmission and high-resolution electron microscopy. Phase decompos ition in the amorphous phase was found to occur during the annealing betwee n the glass transition and crystallization temperatures. The size of non-un iform regions was about 100 nm. The scattering vector corresponding to inte nsity maximum changes from 4.88 to 4.78 nm(-1) from place to place. Nanocry stal groups form during the crystallization. in this temperature region. Th e size of these nanocrystals is about 10-30 nm and there is no amorphous la yer between them. The crystallization mechanism changes when the annealing temperature is below the glass transition temperature. (C) 1999 Elsevier Sc ience B.V. All rights reserved.