Spectroscopic study of Eu3+-doped Gd1−xYxCa4O(BO3)3 prepared by sol-gel method

Eu3+-doped Gd1−xYxCa4O(BO3)3 solid solutions in the form of nanopowders with mean particle size of about 50 nm were prepared by sol-gel method for x = 0.13, 0.44 and 0.60. X-ray examination revealed that compounds prepared by this method are single phase in contrast to compounds prepared by solid state reaction. Room temperature VUV-UV excitation spectra of the 5D0 emission and corresponding VUV-excited emission spectra of Eu3+ were recorded using synchrotron radiation. In addition the excitation spectra in the visible region and the 5D0 luminescence decay curves were measured. Spectroscopic features of nanopowders prepared by sol-gel method were compared with those evaluated for single crystal samples grown by the micro-pulling down technique from charge prepared by sol-gel method. It has been concluded that the sol-gel method facilitates the control of stoichiometry and structural stability of compounds under study.