Ab Initio Study Of Co-59 Nmr Spectra In Co2feal1-Xsix Heusler Alloys

Ab initio electronic structure calculation of a series of Co2FeAl1-xSix Heusler alloys has been performed, using the Korringa-Kohn-Rostoker-coherent potential approximation method to explain experimental Co-59 NMR spectra. Two prominent features are explained semi-quantitatively a global shift of the Co-59 resonance line due to alloying with Al and Si atoms in Co2FeAl1-xSix and the effect of local disorder in creating distinct satellite lines of Co-59 NMR in Co2FeAl. The importance is stressed of the positive contribution to the Co-59 hyperfine field from valence electron polarization, which emerges from the half metallic band structure inherent in Co-based Heusler alloys. (C) 2015 Elsevier B.V. All rights reserved.