Temperature dependence of resistivity and Hall coefficient in strongly disordered NbN thin films

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 dρdT and dRHdT are negative up to 285 K. We observe thatRH(T) varies linearly with ρ(T) for all the films and $[{{R}H(T){-}{R}H(285 K)}{{R}H(285 K)}]={γ}[{{ρ}(T){-}{ρ}(285 K)}{{ρ}(285 K)}]$, 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.