Spectral-luminescence characteristics of solid solutions ZrO2-Eu2O3 crystals

Abstract

Data on the structure of (100-x) mol.% ZrO2 - х mol.% Eu2O3 solid solution concentration series (x = 4, 6, 8, 10, 12, 15, 20, 27) have been presented. The crystals with x = 4 have a hexagonal structure, while those with x = 8 are a mixture of cubic and tetragonal phases. The crystals with x = 10, 12 and 15 have a cubic structure, and those with x = 27 are two-phase and contain cubic modification and pyrochlore phase.Luminescent spectra of the (100-x) mol.% ZrO2 - х mol.% Eu2O3 solid solutions have been taken in the as-grown and air-annealed states. The presence of Eu2+ ions was revealed in (100-x) mol.% ZrO2 - х mol.% Eu2O3 solid solution concentration series (x = 4, 6, 8, 10, 12, 15, 20, 27) after growth, the content of which decreases significantly after heat treatment in air. It has been shown that in (96-85) mol.% ZrO2 - (4–15) mol.% Eu2O3 crystals the relative proportion of optical centers of Eu3+ surrounded by oxygen seven-vertex is lower compared to crystals (96.7–85) mol.% ZrO2 - (3.6–15) mol.% Gd2O3 - 0.1 mol.% Eu2O3. The (73, 80) mol.% ZrO2 - (20, 27) mol.% Eu2O3 crystals contain optical centers of Eu3+ surrounded by oxygen six-vertex with two oxygen vacancies along the diagonal faces of the cubic crystal lattice. Their percentage being higher than in the (79.9, 76.9) mol.% ZrO2 - (20, 33) mol.% Gd2O3 - 0.1 mol.% Eu2O3 crystals.In crystals of (100-x) mol.% ZrO2 - х mol.% Eu2O3 solid solution concentration series (x = 4, 6, 8, 10, 12, 15, 20, 27), the presence of concentration quenching was revealed with increasing concentration of europium ions.