Giant injection magnetoresistance in gallium arsenide/granulated film heterostructures with nanosize cobalt inclusions

Electron transport has been studied in the gallium arsenide/granulated SiO2 film heterostructure with Co nanoparticles and in the gallium arsenide/TiO2 film heterostructure with Co island sublayers. When electrons are injected from a film into a semiconductor, a new phenomenon is observed, which is called injection magnetoresistance. For the SiO2(Co)/GaAs structure with 60 at. % Co in a magnetic field of 23 kOe at a voltage of 50 V, the injection magnetoresistance reaches 5200% at room temperature. (C) 2005 Pleiades Publishing, Inc.