Correlation between the structural and spectroscopic parameters for Cd1−3xGd2x□xMoO4 solid solutions where □ denotes cationic vacancies

Fourier transform IR and Raman spectra of the Cd1−3xGd2x□xMoO4 solid solutions have been studied and analysed using the factor group approach (□ denotes the cationic vacancies). The tetragonal I41/a (C4h6) space group with Z = 2 have been applied in the discussion. The assignment of the bands observed to the internal and external modes has been proposed and related to the formation of the solid solutions in which the gadolinium content has been changed in the range 0–1.0. The optical spectroscopic studies show visible dependence of the transition corresponds to the cationic vacancy on the Gd3+ content. The correlation between the crystallographic and spectroscopic data has been discussed in terms of the structural changes of the solid solutions induced by the defects in the CdMoO4 host lattice.