Study of Temperature Behavior of Luminescence Emission of LaVO_4 and La_(1-x)Eu_xVO_4 Powders

摘要

The La_(1-x)Eu_xVO_4 powders were synthesized by co-precipitation method. Emission spectra of the LaEuVO_4 and La_(1-x)Eu_xVO_4 powders consist of wide non-structural bands of the matrix emission and narrow spectral lines caused by inner f-f electron transitions in the Eu~(3+) ions, respectively. The both types of emission were studied within 8 - 300 K temperature range. Decomposition of spectra of the wide matrix emission on three bands has been carried out and temperature dependencies for each band were studied. Temperature behavior of the Eu~(3+) emission was investigated for lines assigned to different Eu~(3+) centres. Obtained dependencies are analyzed and discussed using proposed schemes of transitions in the VO_4~(3-) groups and structure of the nearest surrounding of the Eu~(3+) emission centres.