Date of Award

1996

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

First Advisor

Dana A. Browne

Abstract

I present a first principles, all electron, linear combination of Gaussian orbitals calculation of a comprehensive collection of magneto-optical properties of the cubic ferromagnetic metals nickel, iron and cobalt based on density functional theory. Among the many magneto-optical effects, this is the first ab initio study of the equatorial Kerr effect for absorption in the optical as well as the X-ray region, where it is called the X-ray magnetic linear dichroism. I find that in the optical region, this effect is of the order of 2% while in the X-ray region, it is of the order of 1% for the incident angles considered. The polar Kerr effect, which is exploited in the laser read-out of digital information stored on a magnetic disk, has also been computed for all three cases. In addition, I have also calculated the X-ray magnetic circular dichroism, total X-ray absorption and soft X-ray Faraday effect at the L$\sb{2,3}$ edges for nickel, iron, and cobalt. Taking the case of cobalt, I have studied the effect of changing the lattice constant on the polar Kerr spectrum. I conclude that in the case of cobalt, a 2% increase in the lattice constant causes the higher peaks in the optical region to shift towards lower energies by about 0.5 eV. My study does not show any significant difference between the polar Kerr spectra of fcc and bcc cobalt for the lattice constants considered. My results in most cases are in good agreement with experimental observations. In cases where they are not, I find that the disagreement is due to the failure of the local density approximation to density functional theory and as such, my results are similar to those of other first principles methods that have been used to calculate some of these properties.

Pages

120

Share

COinS