Full potential results on the magneto-optical properties of the Heusler compoundsCo2FeX (X = Al, Ga, Si and Ge)

Abstract

We have calculated the magneto-optical (MO) properties ofCo2FeX (X = Al, Ga, Si and Ge) Heusler compounds using the full potential linearized augmented planewave (FPLAPW) method as implemented in the WIEN2K code using the local spin densityapproximation (LSDA) and also by using the generalized gradient approximation (GGA)for the electronic exchange and correlation. In all the compounds, Kerr rotationθK has a strong minimum near 2 eV, the value of|θK| corresponding to this minimum being almost as large as in pure Co–Fecompounds. The calculated MO spectra help to identify the features of theexperimental spectra. A comparison of the results shows that the Kerr spectrum isquite similar from both LSDA and GGA but the latter gives better agreementwith experiment. Moreover, we find that inclusion of correlation effects usingGGA+U removes the discrepancy in magnetic moment ofCo2FeX (X = Si, Ge) though it has an insignificant effect on the Kerr spectra.