Effect of annealing on electron dephasing in three-dimensional polycrystalline metals

J. J. Lin; Y. L. Zhong; T. J. Li

doi:doi:10.1209/epl/i2002-00591-8

DOI: 10.1209/epl/i2002-00591-8

Europhys. Lett., 57 (6) , pp. 872-878 (2002)

Effect of annealing on electron dephasing in three-dimensional polycrystalline metals

J. J. Lin¹, Y. L. Zhong² and T. J. Li³

¹ Institute of Physics, National Chiao Tung University Hsinchu 300, Taiwan, ROC
² Department of Physics, National Tsing Hua University Hsinchu 300, Taiwan, ROC
³ Department of Electrophysics, National Chiao Tung University Hsinchu 300, Taiwan, ROC

jjlin@cc.nctu.edu.tw

(Received 30 July 2001; accepted in final form 19 December 2001)

Abstract
We have studied the effect of thermal annealing on electron dephasing times $\tau_\phi$ in three-dimensional polycrystalline metals. Measurements are performed on as-sputtered and annealed AuPd and Sb thick films, using the weak-localization method. In all samples, we find that $\tau_\phi$ possesses an extremely weak temperature dependence as $T\,\rightarrow\,0$ . Our results show that the effect of annealing is non-universal, and it depends strongly on the amount of disorder quenched in the microstructures during deposition. The observed "saturation" behavior of $\tau_\phi$ cannot be easily explained by magnetic scattering. We suggest that the issue of saturation can be better addressed in three-dimensional, rather than lower-dimensional, structures.

PACS
73.23.-b - Electronic transport in mesoscopic systems.
73.20.Fz - Weak or Anderson localization.

© EDP Sciences 2002