Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Site-selective emission spectra of Eu3+: Ca-5(PO4)(3)F
Autore:
Karbowiak, M; Hubert, S;
Indirizzi:
Univ Wroclaw, Fac Chem, PL-50383 Wroclaw, Poland Univ Wroclaw Wroclaw Poland PL-50383 Fac Chem, PL-50383 Wroclaw, Poland Inst Phys Nucl, Grp Radiochimi, F-91406 Orsay, France Inst Phys Nucl Orsay France F-91406 rp Radiochimi, F-91406 Orsay, France
Titolo Testata:
JOURNAL OF ALLOYS AND COMPOUNDS
fascicolo: 1-2, volume: 302, anno: 2000,
pagine: 87 - 93
SICI:
0925-8388(20000428)302:1-2<87:SESOEC>2.0.ZU;2-E
Fonte:
ISI
Lingua:
ENG
Soggetto:
LUMINESCENCE; APATITES; CRYSTALS;
Keywords:
fluoroapatite; europium(3+); site-selective fluorescence spectroscopy;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
18
Recensione:
Indirizzi per estratti:
Indirizzo: Karbowiak, M Univ Wroclaw, Fac Chem, 14 F Joliot Curie St, PL-50383 Wroclaw, Poland Univ Wroclaw 14 F Joliot Curie St Wroclaw Poland PL-50383 nd
Citazione:
M. Karbowiak e S. Hubert, "Site-selective emission spectra of Eu3+: Ca-5(PO4)(3)F", J ALLOY COM, 302(1-2), 2000, pp. 87-93

Abstract

The room temperature site-selective fluorescence and excitation spectra ofEu3+:FAP powder samples as well as the decay times of the observed emission lines associated with the D-5(0) --> F-7(0,1,2) transitions have been measured. In sample I, prepared by the thermally stimulated diffusion of Eu2O3in the solid state, Eu3+ reside only in the Ca(II) location which has C-s symmetry. Experimental values for the Stark energy levels have been determined for three well-separated sites. Sites A and B exhibit very similar spectral features attributed to the presence of the charge-compensating O2- ionin the F- position in the FAP lattice, whereas for Eu3+ in site C the charge is most probably compensated by vacancies according to 3Ca(2+) --> 2Eu(3) +Vacancy substitution. In sample II, prepared by precipitation of Eu3+(1%):FAP from solution, Eu3+ substitute for calcium in the Ca(I) position exclusively and three sites with C-3 symmetry have been identified. Substitution of 3Ca(2+)/2Eu(3+) is the most probable charge-compensation mechanism. Heating of sample II stimulates the migration of Eu3+ from the Ca(I) position to the low symmetry Ca(II) site. (C) 2000 Elsevier Science S.A. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 01/12/20 alle ore 19:36:11