Temperature-dependent electrical resistivity and magnetoresistance characteristics of Zn1−xVxO thin films above Mott critical density

Abstract

Temperature-dependent (5–200 K) electrical resistivity and magnetoresistance (MR) measurements were carried out on [Formula: see text] (x = 0.5–4 at.%) thin films grown by pulsed laser deposition (PLD). The free electron concentration in the films was found to be in the range of [Formula: see text](1.7–4.7) [Formula: see text] which is much higher compared to the Mott critical density required for the onset of insulator-to-metal transition in ZnO. All the films exhibited small negative MR in the entire temperature and magnetic field range indicating weak-localization as the dominant effect. However, some unusual MR behavior was observed at 5 K for the film with highest static-disorder parameter. Such characteristics have been well-explained by considering the interplay of negative MR (arising due weak-localization and spin-disorder scattering) and positive MR (caused by s–d exchange interaction induced spin-splitting of the conduction band).