Tunable large field magnetoconductance of ZnO, ZnMnO, and ZnCoO thin films

Magnetoconductivity of ten ZnO, Zn 1 − x Co x O, and Zn 1 − x Mn x O thin films with nominal concentrations of 2.0 at.% and 0.1 at.% of Co 2 + and Mn 2 + ions, respectively, has been analyzed in the temperature range from 5 K to 200 K in in-plane and out-of-plane magnetic fields up to 6 T. The formation of a highly conducting surface layer can be controlled during thin film deposition, leading to a large variation of the sheet resistance, namely, from 2 × 10 3 Ω / ◻ to 1 × 10 5 Ω / ◻ at room temperature. Depending on the thickness of the highly conducting surface layer, a single two-dimensional (2D), a single three-dimensional (3D), or a two-dimensional and three-dimensional (2D + 3D) parallel conducting model was chosen to analyze the measured magnetoconductivity of the magnetic ZnO thin films with different electron spins ( S = 5 / 2 for Zn 1 − x Mn x O and S = 3 / 2 for Zn 1 − x Co x O) and with different Lande g -factors (isotropic for 3D Zn 1 − x Mn x O and 2D Zn 1 − x Co x O and anisotropic for 2D Zn 1 − x Mn x O and 3D Zn 1 − x Co x O).Magnetoconductivity of ten ZnO, Zn 1 − x Co x O, and Zn 1 − x Mn x O thin films with nominal concentrations of 2.0 at.% and 0.1 at.% of Co 2 + and Mn 2 + ions, respectively, has been analyzed in the temperature range from 5 K to 200 K in in-plane and out-of-plane magnetic fields up to 6 T. The formation of a highly conducting surface layer can be controlled during thin film deposition, leading to a large variation of the sheet resistance, namely, from 2 × 10 3 Ω / ◻ to 1 × 10 5 Ω / ◻ at room temperature. Depending on the thickness of the highly conducting surface layer, a single two-dimensional (2D), a single three-dimensional (3D), or a two-dimensional and three-dimensional (2D + 3D) parallel conducting model was chosen to analyze the measured magnetoconductivity of the magnetic ZnO thin films with different electron spins ( S = 5 / 2 for Zn 1 − x Mn x O and S = 3 / 2 for Zn 1 − x Co x O) and with different Lande g -factors (isotropic for...