CRYSTAL-CHEMISTRY AND SPECTROSCOPIC STUDIES OF PHASES OF THE SOLID-SOLUTION K2RBEU1-XBIX(ASO4)(2)

This paper reports the study of different phases of arseniates with th e general formula K2RbEu1-xBix(AsO4)(2) (0 less than or equal to x les s than or equal to 0,24). These compounds were prepared by solid state reactions. The limit x of the solid solution was determined by X-ray diffraction, Raman spectroscopy and using Eu3+ as local structural pro bes. Analysis of the Raman spectra and the fluorescence of Eu3+ by the groups theory is used to confirm and complete the structural data of these materials, A vibronic coupling is proposed to cc-plain the proce ss of europium emission observed under 647,1 nm excitation.