Atomic mechanism of the amorphization process in transition metal-metalloid and metal-metal alloys

Abstract

By means of the molecular dynamics method using pair interaction potentials calculated within the framework of the pseudo-potential theory the rapid quenching process is simulated. The short-range order and atomic structure of Ni<SUB>80</SUB>B<SUB>20</SUB>, Ni<SUB>80</SUB>Zr<SUB>20</SUB> and Zr<SUB>80</SUB>Be<SUB>20</SUB> alloys in amorphous state are investigated. Total and partial radial atomic distribution functions, nearest interatomic distances and coordination numbers are determined. It is found that amorphization both in transition metal-metalloid and in metal-metal alloys occurs according to the unified formation mechanism of low-dimensional nanometric dendritelike aggregates. For each type of atoms the velocity distributions and spectra of vibrational states are received. The non-standard behavior of amorphous alloys is supposed to be connected with disturbing thermodynamic canonicity states, caused by the presence of nanocrystal heterogeneities of composition.