%0 Journal Article
%A Kudryavtseva, I.
%A Klopov, M.
%A Lushchik, A.
%A Lushchik, Ch
%A Maaroos, A.
%A Pishtshev, A.
%T Electronic excitations and self-trapping of electrons and holes in CaSO<sub>4</sub>
%J Physica scripta
%V 89
%N 4
%@ 1402-4896
%C Bristol
%I IoP Publ.
%M PUBDB-2015-01929
%P 044013
%D 2014
%X A first-principles study of the electronic properties of a CaSO4 anhydrite structural phase has been performed. A theoretical estimation for the fundamental band gap (p → s transitions) is Eg = 9.6 eV and a proper threshold for p → d transitions is Epd = 10.8 eV. These values agree with the data obtained for a set of CaSO4 doped with Gd3+, Dy3+, Tm3+ and Tb3+ ions using the methods of low-temperature highly sensitive luminescence and thermoactivation spectroscopy. The results are consistent with theoretical predictions of a possible low-temperature self-trapping of oxygen p-holes. The hopping diffusion of hole polarons starts above  40 K and is accompanied by a  50–60 K peak of thermally stimulated luminescence of RE3+ ions caused due to the recombination of hole polarons with the electrons localized at RE3+. There is no direct evidence of the self-trapping of heavy d-electrons, however, one can argue that their motion rather differs from that of conduction s-electrons.
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000333449400014
%R 10.1088/0031-8949/89/4/044013
%U https://bib-pubdb1.desy.de/record/208877