• Gd-doped GaN;
  • dilute magnetic semiconductor;
  • molecular beam epitaxy


Effects of growth conditions on structural and magnetic properties in Gd-doped GaN layers grown by plasma-assisted molecular beam epitaxy have been investigated. It is found that the growth of Gd-doped GaN layers with atomically flat surface morphologies requires relatively high Ga fluxes compared with the growth of GaN. For these Gd-doped GaN layers grown under Ga-rich conditions, (0002) diffraction spots of GaGdN appear and shift toward low scattering angle side depending on the concentration of Gd, indicating the expansion of the c-axis lattice constant due to the incorporation of Gd. In contrast, for the Gd-doped GaN layers grown under N-rich condition, just the (0002) diffraction spot of GaN is observed irrespective of the concentration of Gd. Although all the samples show hysteresis in the M-H curves at room temperature, the samples grown under the Ga-rich conditions have higher coercevities and larger saturation magnetizations than the samples grown under the N-rich conditions. Based on the findings, we will discuss the origin of ferromagnetic behaviour observed in Gd-doped GaN (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)