Band conduction effects in the ESR spectra of semiconducting Na0.01V2O5

We report on the temperature- and orientation dependence of the ESR linewidth of d-electrons in semiconducting Na_0.01V₂O₅. The observed line narrowing results from hopping of the d-electrons between localized states. At higher temperatures a line broadening occurs which is due to excitation of the d-electrons into a conduction band. The corresponding activation energies, determined from ESR measurements, agree with values derived from electronic conductivity.