Weak localization in beryllium films

Abstract

Beryllium films with thickness from 44 to 470 nm have been grown via direct current magnetron sputtering. The negative magnetoresistance was observed below ∼10 K, which can be well described by the three-dimensional weak localization theory. The extracted dephasing time τϕ obeys the temperature-scaling law of τϕ−1∝Tp˜. The fitting results indicate that the temperature exponent p˜ increases from 0.8 to 1.7 while increasing film thickness. The physical mechanism behind this phenomenon may be caused by the crossover from Belitz-Wysokinski electron-electron interaction to incomplete drag electron-phonon interaction, or originated from the sole electron-phonon interaction regulated by the thermal phonon dimensionality. Further evidence is required to determine the exact mechanism.