Characterization and local magnetic modification of ion irradiated GaMnAs

We study the influence of ion irradiation on magnetic, magneto-transport and structural properties in Ga0.94Mn0.06As films. The carrier concentration is accurately controlled by defects introduced via ion irradiation. Magnetic properties strongly depend on the hole concentration. We present the modification of coercivity, magnetic anisotropy, and magnetotransport properties during such a procedure. By X-ray diffraction and Raman spectra, we exclude the effects from structural changes. Using lithograph made resist mask, one can realize planar local structures with different magnetic properties, indicating the promising future of ion irradiation for spintronics device fabrication.