Magnetoresistance Behavior of Silver‐Doped Zinc Oxide Films

Silver (0.24 at%) doped zinc oxide (AgZnO) films are deposited on glass substrates using electron beam evaporation. The resistance is measured in the temperature range of 4–380 K under magnetic fields ( H ) of 0.1 and 0.25 T. In the low‐temperature range, the resistance of the annealed AgZnO film exhibits peaks at 101, 130, and 160 K when H = 0 T. The peaks at 130 and 160 K disappear at H = 0.1 T, while the peak at 101 K exhibits positive magnetoresistance (MR) below 122 K and transitions to negative MR above 122 K at 0.25 T. At high temperatures, the resistance of the annealed AgZnO film follows the Arrhenius equation, with the activation energy increasing from 0.59 to 0.73 and 0.74 eV under H = 0.1 and 0.25 T, respectively, in the temperature ranges of 230–380 K and 230–320 K. In the low‐temperature range, the resistance is governed by Mott variable‐range hopping (VRH) model. A crossover from Mott to Efros–Shklovskii VRH mechanism is observed at different temperature ranges: 165–170 K, 145–165 K, and 135–165 K for H = 0, 0.1 and 0.25 T, respectively. Moreover, the Coulomb gap decreases, and the T M / T ES ratio increases with the magnetic field, indicating changes in the electronic structure of the AgZnO film.