Magnetoresistance and anomalous Hall effect in magnetic ZnO films
2007; American Institute of Physics; Volume: 101; Issue: 6 Linguagem: Inglês
10.1063/1.2715846
ISSN1520-8850
AutoresQingyu Xu, Lars Hartmann, Heidemarie Schmidt, H. Hochmuth, Michael Lorenz, Rüdiger Schmidt‐Grund, Chris Sturm, D. Spemann, Marius Grundmann, Yuzi Liu,
Tópico(s)Electronic and Structural Properties of Oxides
ResumoMagnetotransport measurements were performed on n-type conducting Co-doped ZnO and Mn-doped ZnO films prepared by pulsed laser deposition on a-plane sapphire substrates, and positive magnetoresistance (MR) was observed at low temperature. The positive MR decreases drastically with the free electron concentration n exceeding 1019cm−3 and reveals almost the same dependency on n for Co-doped ZnO and Mn-doped ZnO. This hints towards a similar s-d exchange constant in both types of magnetic ZnO films. For Co-doped ZnO, the saturated anomalous Hall resistivity increases with decreasing electron concentration. No anomalous Hall effect was observed in Mn-doped ZnO. Within a free electron approximation the positive MR may be related with the spin polarization of conducting electrons due to s-d exchange interactions. The modeled spin splitting of the conduction band is smaller than 10meV.
Referência(s)