ANNEALING SAMPLES OF THE SUPERCONDUCTING COMPOUND NB3AU WITH THERMALLY INDUCED DISORDER

To investigate the kinetics of recovery of anti-site disorder in the A15 compound Nb3Au, isochronal and isothermal annealing procedures at intermediate temperatures (between 833 and 1043 K) were performed on grains quenched from 1355(1) K. From these experiments, the vacancy migration enthalpy and its pre-exponential factor were determined as 0.39 eV and 2.7 x 10(2) s, respectively. The atomic-migration enthalpy and its pre-exponential factor were found to be 1.43 eV and 7.1 x 10(-2) s, respectively. These values will be compared with data for the A15 compound V3Ga, and for Ca3Rh4Sn13 which is a superconductor with an A15 substructure, and with data on ball-milled Nb3Au.