CHEMICAL AND INTERFACE EFFECTS ON GLASS-FORMING ABILITY UNDER ION MIXING IN ZR-TA SYSTEM OF POSITIVE HEAT OF FORMATION

Amorphous alloy films were formed by room temperature 200 keV xenon io n mixing of multilayers in a relatively broad composition range in the Zr-Ta system, which has a positive heat of formation of + 4 kJ mol(-1 ). A free energy diagram was constructed to include the free energy cu rves of the amorphous phase and the multilayers, to which the previous ly missing term of the excess interfacial free energy was calculated a nd added. It turned out that the interface plays a role in influencing the alloying behavior in such system and the calculated diagram provi ded a reasonable interpretation of the observed amorphization. Two new metastable crystalline phases of both fee structures were obtained.