Svane, Axel and Santi, G. and Szotek, Zdzislawa and Temmerman, Walter and Strange, Paul and Horne, M. and Vaitheeswaran, G. and Kandiana, V. and Petit, Leon and Winter, Herman (2004) Electronic structure of Sm and Eu chalcogenides. Physica Status Solidi B, 241 (14). pp. 3185-3192. ISSN 0370-1972. (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)
The ground state configuration of the monochalcogenides of Sm and Eu is determined from total energy calculations using the self-interaction corrected local-spin-density approximation. The Sm chalcogenides, with the exception of SmO, are characterized by divalent f(6) Sm ions, while all the Eu chalcogenides have divalent f(7) Eu ions in the ground state. With pressure, the Eu and Sm chalcogenides exhibit isostructural transitions into an intermediate valent state, which in the total energy calculations is represented by localized f(5) configurations on the Sm ions (f(6) on Eu ions) together with a partly occupied f-band at the Fermi level. The energy of the fundamental f --> d transition, which determines the value of the semiconducting gap, is determined by total energy calculations of the charged rare earth ion (Eu+ or Sm+) in a supercell approach with one f-electron removed. The pressure coefficients are in excellent agreement with experiment, and the occurrence of isostructural transitions is intimately related to the closure of the band gap.
|Subjects:||Q Science > QC Physics|
|Divisions:||Faculties > Science Technology and Medical Studies > School of Physical Sciences > Functional Materials Group|
|Depositing User:||Paul Strange|
|Date Deposited:||04 Sep 2008 15:55|
|Last Modified:||07 May 2014 11:07|
|Resource URI:||https://kar.kent.ac.uk/id/eprint/4699 (The current URI for this page, for reference purposes)|