The crystal structures of new rare earth-based germanate compounds (Ca3Pr2Ge3O12, Ca3Nd2Ge3O12, Ca3Sm2Ge3O12, Ca3Gd2Ge3O12 and Ca3Dy2Ge3O12) have been determined by Rietveld refinement calculations on the collected synchrotron X-ray diffraction powder patterns. A different distribution of the rare earth ions in the three available crystal sites was observed, as the main structural feature. The reasons of the instability of the silico-carnotite structure for lanthanide ions out of the range Pr-Dy have been proposed. Finally, the luminescence spectroscopy of the Eu3+ dopant ion in Ca3Gd2Ge3O12 was presented and analyzed taking into account the observed structural characteristics. The Eu3+ luminescence spectroscopy was also compared with the one of Eu3+ doped Ca3Gd2Si3O12 and Ca3Lu2Si3O12 isostructural materials
Titolo: | Structural investigation of the new Ca(3)Ln(2)Ge(3)O(12) (Ln=Pr, Nd, Sm, Gd and Dy) compounds and luminescence spectroscopy of Ca3Gd2Ge3O12 doped with the Eu3+ ion |
Autori: | |
Data di pubblicazione: | 2013 |
Rivista: | |
Abstract: | The crystal structures of new rare earth-based germanate compounds (Ca3Pr2Ge3O12, Ca3Nd2Ge3O12, Ca3Sm2Ge3O12, Ca3Gd2Ge3O12 and Ca3Dy2Ge3O12) have been determined by Rietveld refinement calculations on the collected synchrotron X-ray diffraction powder patterns. A different distribution of the rare earth ions in the three available crystal sites was observed, as the main structural feature. The reasons of the instability of the silico-carnotite structure for lanthanide ions out of the range Pr-Dy have been proposed. Finally, the luminescence spectroscopy of the Eu3+ dopant ion in Ca3Gd2Ge3O12 was presented and analyzed taking into account the observed structural characteristics. The Eu3+ luminescence spectroscopy was also compared with the one of Eu3+ doped Ca3Gd2Si3O12 and Ca3Lu2Si3O12 isostructural materials |
Handle: | http://hdl.handle.net/11562/637355 |
Appare nelle tipologie: | 01.01 Articolo in Rivista |