Amorphization of metal films by low temperature ion irradiation. An in situ PAC-study for AuIn2 and In3Pd films

Crystalline films of the intermetallic compounds AuIn2 and In3Pd can be amo rphized by irradiation with 350 keV noble gas ions (He, Ar. Kr) at low temp eratures. To study this process on a microscopic scale, the gamma gamma-per turbed angular correlation technique (PAC) was applied in combination with resistance measurements both performed in situ. AuIn2 and In3Pd-films were prepared by flash evaporation and implanted with radioactive In-111 probe a toms at room temperature. After annealing and recooling the crystalline fil ms to 77 K, complete amorphization of the films can be achieved by stepwise increasing the fluence. From the PAC results as well as from the resistivi ty data, the amorphous volume fraction is extracted as a function of the io n fluence. The description of the transformation kinetics as obtained by th e microscopic PAC-method is found to be in good agreement with that deduced from transport measurements. (C) 1999 Elsevier Science B.V. All rights res erved.