Enhanced positive magnetoresistance effect in GaAs with nanoscale magneticclusters

The enhanced positive magnetoresistance effect has been observed in GaAs co ntaining nanoscale magnetic clusters. The ferromagnetic metallic clusters w ere embedded into GaAs by Mn ion implantation and rapid thermal annealing. Positive magnetoresistance in these structures has been observed and attrib uted to the enhanced geometric magnetoresistance effect in inhomogeneous se miconductors with metallic inclusions. The additional enhancement of positi ve magnetoresistance under light illumination is due to the higher mobility of photoexcited electrons in comparison with the mobility of holes in p-ty pe GaAs prepared by Mn ion implantation. (C) 2001 American Institute of Phy sics.