Annealing Effect On Magneto-Transport Properties Of Amorphous Ge1-Xmnx Semiconductor Thin Films

Amorphous Ge1-xMnx semiconductor thin films grown by low temperature vapor deposition were annealed at various temperatures from 400 to 700 degrees C for 3 minutes in high vaccum chamber. The electrical and magnetotransport properties of as-grown and annealed samples have been studied. X-ray diffraction patterns analysis revealed that the samples still maintain amorphous state after annealling at 500 degrees C for 3 minutes and they were crystallized when annealing temperature increase to 600 degrees C. Temperature dependence of resistivity measurement implied that as-grown and annealed Ge1-xMnx films have semiconductor characteristics, the increase of resistivity with annealling temperature was obseved. The 700 degrees C-annealed sample exhibited negative magnetoresistance (MR) at low temperatures and the MR ratio was similar to 8.5% at 10 K. The asymmetry was present in all MR curves. The anomalous Hall Effect was also observed at 250 K.