American Physical Society, Physical review B, 13(80), 2009
DOI: 10.1103/physrevb.80.134514
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We report the temperature dependence of resistivity (ρ) and Hall coefficient (RH) in the normal state of homogeneously disordered epitaxial NbN thin films with kFl∼1.68–10.12. The superconducting transition temperature (Tc) of these films varies from 2.7 to 16.8 K. While our least disordered film displays usual metallic behavior, for all the films with kFl≤8.13, both dρ/dT and dRH/dT are negative up to 285 K. We observe thatRH(T) varies linearly with ρ(T) for all the films and [RH(T)−RH(285 K)/RH(285 K)]=γ[ρ(T)−ρ(285 K)/ρ(285 K)], where γ=0.68±0.11. Measurements performed on a 2-nm-thick Be film show similar behavior with γ=0.69. This behavior is inconsistent with existing theories of localization and e-e interactions in a disordered metal.