Magnetoresistance of PrBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} thin films
- Department of Applied Physics, University of Twente, P.O. Box 217, NL-7500 AE Enschede (Netherlands)
Transport of charge carriers in PrBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} (PBCO) is often described by variable-range hopping (VRH). Until now the VRH mechanism was confirmed merely on the basis of a temperature dependence of the resistivity following Mott`s law. In this article we show a positive magnetoresistance in PBCO thin films, depending exponentially on the applied magnetic field. This provides substantial additional evidence for a variable-range hopping transport mechanism. Both a strong-field and a weak-field magnetoresistance can be identified. At temperatures above 30 K we observe weak-field magnetoresistance, at 4.2 K we detect a transition from weak-field to strong-field magnetoresistance at a magnetic field of approximately 4.5 T. In the weak-field regime the radius of the localized wave function is only affected marginally by the applied magnetic field. In the strong-field regime the radius of the localized wave function decreases with increasing magnetic field. From the measurements in the strong-field regime we obtain an estimate for the two-dimensional density of localized states in the PBCO thin film of approximately 2{times}10{sup 13} 1/eVm{sup 2}.
- OSTI ID:
- 132879
- Journal Information:
- Physical Review, B: Condensed Matter, Vol. 52, Issue 21; Other Information: PBD: 1 Dec 1995
- Country of Publication:
- United States
- Language:
- English
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