Full potential results on the magneto-optical properties of the Heuslercompounds Co2FeX (X = Al, Ga, Si and Ge)

Abstract

We have calculated the magneto-optical (MO) properties of Co2FeX (X = Al, Ga, Si and Ge) Heusler compounds using the full potential linearized augmented plane wave (FPLAPW) method as implemented in the WIEN2K code using the local spin density approximation (LSDA) and also by using the generalized gradient approximation (GGA) for the electronic exchange and correlation. In all the compounds, Kerr rotation K has a strong minimum near 2eV, the value of |K| corresponding to this minimum being almost as large as in pure Co-Fe compounds. The calculated MO spectra help to identify the features of the experimental spectra. A comparison of the results shows that the Kerr spectrum is quite similar from both LSDA and GGA but the latter gives better agreement with experiment. Moreover, we find that inclusion of correlation effects using GGA+U removes the discrepancy in magnetic moment of Co 2FeX (X = Si, Ge) though it has an insignificant effect on the Kerr spectra. © 2009 IOP Publishing Ltd.