Spin-flip scattering times from weak localization studies of Cu$_{93}$Ge$_4$Au$_3$ thin films

We have fabricated a series of Cu$_{93}$Ge$_{4}$Au$_{3}$ thin films by sputtering deposition technique. The Ge atoms were introduced to enhance the impurity scattering while the Au atoms were introduced to enhance spin-orbit scattering. The films were either 150 or 200 angstroms thick. The residual resistivities were tuned by adjusting the deposition rate and varied between 14 and 59 $\mu \Omega $ cm. Resistance measurements revealed ln$T$ behavior below 10 K or so, which could be ascribed to Kondo effect in addition to 2D electron-electron interaction effects. The electron dephasing times have been measured through the weak-localization-induced magnetoresistances. In particular, the spin-flip scattering times have been extracted from the total dephasing times. We will present the temperature and disorder behavior of the spin-flip scattering times and compare them with the Nagaoka-Suhl and recent theoretical calculations.