Bias dependence of magnetoresistance in Fe-Al2O3 granular thin films
Abstract
This paper reports on the magnetotransport behavior of Fe-Al2O3 granular thin films when the injected dc current is varied. The electric resistance as a function of temperature, magnetoresistance, and the current vs applied bias potential measurements were used to characterize the samples. It was found that the transport mechanism which best describes the electronic properties of these samples is variable range hopping. Non-Ohmic behavior was observed and is claimed as responsible for the great modification of the electronic characteristics of the system as a function of the applied bias potential. Inversion of the tunneling magnetoresistance is observed for applied bias potential greater than 3 V. Such inverted magnetoresistance comes from the activation of low resistivity tunneling paths that are promoted by increasing the bias potential. An expression is proposed to describe the magnetoresistance behavior.
- Publication:
-
Journal of Applied Physics
- Pub Date:
- June 2002
- DOI:
- 10.1063/1.1479481
- Bibcode:
- 2002JAP....91.9909B
- Keywords:
-
- iron;
- alumina;
- discontinuous metallic thin films;
- magnetic thin films;
- tunnelling;
- magnetoresistance;
- electrical resistivity;
- ferromagnetic materials;
- Aluminum Oxides;
- Direct Current;
- Electrical Resistivity;
- Electron Tunneling;
- Ferromagnetic Materials;
- Iron;
- Magnetic Films;
- Magnetic Properties;
- Magnetoresistivity;
- Metal Films;
- Thin Films;
- Transport Properties;
- Tunneling;
- 73.61.At;
- 72.25.Mk;
- 75.70.Ak;
- 75.70.Pa;
- 73.40.Gk;
- 75.50.Bb;
- Solid-State Physics;
- Metal and metallic alloys;
- Spin transport through interfaces;
- Magnetic properties of monolayers and thin films;
- Tunneling;
- Fe and its alloys