Localization Phenomena in Disordered Tantalum Films

Abstract

Using dc transport and wide-band spectroscopic ellipsometry techniques we study localization phenomena in highly disordered metallic β-Ta films grown by rf sputtering deposition. The dc transport study implies non-metallic behavior (dr/dT<0), with negative temperature coefficient of resistivity (TCR). We found that as the absolute TCR value increased, specifying an elevated degree of disorder, the free charge carrier Drude response decreases, indicating the enhanced charge carrier localization. Moreover, we found that the pronounced changes occur at the extended spectral range, involving not only the Drude resonance, but also the higher-energy Lorentz bands, in evidence of the attendant electronic correlations. We propose that the charge carrier localization, or delocalization, is accompanied by the pronounced electronic band structure reconstruction due to many-body effects, which may be the key feature for understanding the physics of highly disordered metals.

arXiv comment19 pages, 5 figures, 1 table

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Cited by in corpus (5)

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• Bismuth layer properties in the ultrathin Bi-FeNi multilayer films probed by spectroscopic ellipsometry
• Bi layer properties in the Bi-FeNi GMR-type structures probed by spectroscopic ellipsometry