Temperature-dependence of the Hall coefficient of NdNiO₃ thin films

Abstract

The Hall coefficient of epitaxial NdNiO3 films is evaluated in a wide range of temperatures, from the metallic into the insulating phase. It is shown that for temperatures for which metallic and insulating regions co-exist, the Hall coefficient must be corrected for the time-dependence in the longitudinal resistance, which is due to a slow evolution of metallic and insulating domains. The positive Hall and negative Seebeck coefficients, respectively, in the metallic phase are characteristic for two bands participating in the transport. The change in the sign of the Hall coefficient to negative values in the insulating phase is consistent with the suppression of the contribution from the large hole-like Fermi surface, i.e., the formation of a (pseudo)gap due to charge ordering.