THE TEMPERATURE-DEPENDENCE OF THE ELECTRICAL-RESISTIVITY OF AL-ZN ALLOY THIN-FILMS

The electrical resistivity of vacuum evaporated Al-40 wt. % Zn thin films was found to decrease as thickness increased, thus exhibiting a size effect. Isothermal annealing of the quenched samples started with an anomalous resistivity increase to maxima followed by a normal decrease to limiting values. In the Guinier-Preston zone temperature range a measurable difference in resistivity was affected by the annealing temperature which is not the case of the bulk material. The role played by the quenched-in vacancies, grain boundary migration, phonons and the state of the solute atoms were used to explain the observed resistivity variations which were found to consist with the expected state of the alloy at the different testing temperatures. The irregularities of the position and magnitude of the observed maxima were explained in terms of the attenuation of the incident electron wave within the film as a multiple scattering effect. The observed anomalies in the resistivity during annealing were attributed to phase transformation and atomic ordering.