5D0→7F0 transitions of Sm2+ in SrMgF4:Sm2+

Temperature-dependent emission spectra of Sm2+-doped SrMgF4 have been obtained in the temperature range from 50 to 300 K. At 50 K, six bands are observed for the very strong D-5(0) --> F-7(0) transition, in agreement with the reported sixfold crystal superstructure. The overall splitting of more than 70 cm(-1) highlights the important structural differences of the six Sr sites. Upon heating progressively to room temperature, the spectra change progressively with a more pronounced change between 270 and 300 K. These observations suggest the possibility of a complex structural behavior for SrMgF4 which will require new experiments. (C) 2003 Elsevier B.V. All rights reserved.