Abstract
A method is described for calculating crystal fields for rare-earth ions in non-magnetic hosts. Screening is included by performing a Bohm-Pines-like unitary transformation on the starting Hamiltonian which contains kinetic-energy and Coulombic energies of electrons in the presence of fixed nuclei. Contributions from core orbitals are included as well as components from a 5d virtual bound state assumed to contain no more than one electron. The coupling between the 4f impurity and the majority s-like conduction band is assumed to be weak. Degenerate perturbation theory has been used and in zeroth order it has been assumed that the impurity potential is sufficiently strong to remove one state from the s-band. The many-body nature of the problem has been incorporated using a second quantised representation. Further unitary transformations are performed to weaken the 4f-conduction band coupling before averaging over the conduction states to obtain an effective 4f Hamiltonian.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Physica A: Statistical Mechanics and its Applications
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
