Characterization of Ga-Mn Decagonal Quasicrystals in GaAs

Abstract

AbstractGa-Mn decagonal quasicrystals (DQC), as well as a Ga-Mn approximant and a normal crystal in GaAs are investigated by electron energy-loss spectroscopy (EELS) and energy dispersive X- ray spectroscopy (EDS) combined with Z-contrast imaging. Plasmon peak positions (Ep), full- width-half-maxima (FWHM) and Mn L3/L2ratios of these three phases are derived from their low-loss spectra and core-loss spectra respectively. Mn, Ga and As distributions in ion implanted GaAs layers are characterized by EDS at line-scan mode. These results show that the Ga-Mn DQC has higher Ep and FWHMs than those of its normal crystal counterpart, as well as all other reported QCs. The much larger L3/L2 intensity ratio of the Ga-Mn DQC over that of the Al-Mn icosahedral quasicrystals (IQC) may suggest Mn atoms in the Ga-Mn DQC have much larger local magnetic moments.