Unusual transition from negative to positive magnetoresistance in n-n heterojunctions composed of La0.9Hf0.1MnO3 and Nb-doped SrTiO3
Department of Physics, the University of Hong Kong - Hong Kong, China
Accepted: 2 August 2011
We fabricated n-n heterojunctions by composing La0.9Hf0.1MnO3 layers and Nb-doped SrTiO3 crystals using pulsed-laser deposition. The formed heterojunctions demonstrated good rectifying behavior in a wide range of temperatures with or without magnetic field. It is notable that the magnetoresistance changed from negative to positive as temperature increased. The appearance of the positive magnetoresistance at higher temperatures might be understood by the occupation of minority spin carriers in the t2g ↓ sub-band. These results might be of merits for potential application in manganite-based spintronic devices.
PACS: 75.70.Cn – Magnetic properties of interfaces (multilayers, superlattices, heterostructures) / 75.47.Gk – Colossal magnetoresistance / 85.75.Ss – Magnetic field sensors using spin polarized transport
© EPLA, 2011