Atomic structure and crystallization processes of amorphous (Co,Ni)-P metallic alloy

This work concerns the in situ investigation of the atomic structure of (Co,Ni)-P alloys during relaxation and crystallization by high resolution transmission electron microscopy. The CoP-CoNiP alloys, in the initial state, have a hierarchical network-like disordered structure. Crystallization starts at 200-250 degrees C on the network frame and cell boundaries. In the early stages, crystal growth occurs at the free surface, then the remaining material in the volume is crystallized. The diffusion coefficient at the start of crystallization is 1.2-2.4 x 10(-18) m(2)/s at 250 degrees C and we assume that the high diffusion speed is due to surface diffusion. (C) 2015 Elsevier B.V. All rights reserved.