ELECTRON-ELECTRON INTERACTION AND WEAK-LOCALIZATION EFFECTS IN TI-AL ALLOYS

We have measured the resistivities rho of Ti1-xAlx alloys (0.00 less-than-or-equal-to x less-than-or-equal-to 0.19) between 4 and 300 K. As the temperature T is lowered to liquid-helium temperatures, a resistivity rise [rho(T)-rho(25 K)]/square-root T is similar to -rho2.5(25 K) is observed. This functional form is due to electron-electron interaction effects in a three-dimensional disordered metal. Particularly, the absolute magnitude of the measured resistivity rise is consistent within approximately 25% with the theoretical prediction. At room temperature, the temperature coefficient of resistivity (1/rho)(drho/dT) decreases monotonically with increasing x or, equivalently, rho. The essential characteristics of the variation of (1/rho)(drho/dT) with rho is explained in terms of a theory that considers a competition between the quantum-mechanical effects of weak localization and the classical Boltzmann electron transport.