Disorder Driven Weak Localization and Phase Coherent Electron Transport in Ga Doped (Zn:V)O Thin Films

Abstract

We have observed disorder driven weak localization with phase coherent electron transport in Ga doped (Zn:V)O thin films grown by pulsed laser deposition. All the Ga doped (Zn:V)O thin films with fixed 1 at% V and varying (0–5 at%) Ga concentration exhibit metal like behavior by Mott's definition while temperature coefficient of resistivity (TCR) systematically changes its sign with variation of temperature. This anomaly has been understood by considering quantum corrections to classical Boltz mann conductivity where significant contribution of weak localization has been confirmed from the observation of negative magneto resistance (MR) in temperature dependent magneto-transport measurements at varying magnetic fields. Phase coherent length of Ga doped (Zn:V)O thin films varies with both Ga concentration and measurement temperature and attains a maximum value ∼320 nm at 5K for 2 at% of Ga concentration. The nature of temperature dependence on phase coherent length demonstrates electron-electron scattering as the dominant phase breaking mechanism in the Ga doped (Zn:V)O thin films. Phase coherent electron transport and its tunability with Ga concentration in (Zn:V)O thin films is expected to have potential in futuristic phase coherent electron transport devices.