摘要
Structural and magnetic properties of Ga0.93 Mn0.07 As layers grown on (001) and (311) A GaAs substrates by molecular-bean epitaxy are investigated. The as-grown (001) and (311) A Ga0.93 Mn0.07 As layers exhibit the same Curie temperature (TC) of 80 K. However, upon annealing, the TC 's of the (001) and (311) A Ga0.93 Mn0.07 As layers are enhanced by 80 and 60 K, respectively. X-ray diffraction studies reveal that the AsGa defects cannot be removed by low-temperature annealing, and a higher concentration of AsGa defects exist in the (311) A layers than in the (100) reference layers. The less enhancement in TC by annealing for the (311) A Ga0.93 Mn0.07 As layer can be ascribed to the larger amount of AsGa defects in the material. © 2008 American Institute of Physics.