Electron irradiation induced crystalline-amorphous transition in a Co 75B 25 alloy

Abstract

The relative stability of crystalline and amorphous phases in a Co 75B 25 alloy during 2 MeV electron irradiation was examined as a function of irradiation temperature by ultra-high voltage electron microscopy. At temperatures below 160 K, the crystalline phase is rendered amorphous during irradiation and the amorphous phase is always stable regardless of starting conditions, while at temperatures above 310 K, the amorphous phase undergoes the crystallization during irradiation and the crystalline phase is always stable relative to the amorphous phase. The crystallization temperature in the absence of irradiation was approximately 725 K. At temperatures between 160 K and 310 K, the alloy remains in the starting condition, i.e. either crystalline or amorphous, during irradiation.