Intrinsic luminescence centers in scandia, yttria, and their solid solutions

Abstract

Pulsed cathodoluminescence (PCL) of Y2O3 and Sc2O3 powders, as well as of ceramic samples of binary (11 mol % Sc2O3–ZrO2 and 10 mol % Y2O3–ZrO2) and ternary (xSc2O3–(10–x)Y2O3–ZrO2) (x = 5, 6, 7, 8 mol %) solid solutions are studied in the range of 300–850 nm at room temperature. In Y2O3 and Sc2O3, series of strong narrow luminescence bands emitted by surface bound radicals ...0...0>-Y=O and ...0...0>-Sc=O are found. The PCL spectra of xSc2O3–(10–x)Y2O3–ZrO2 ceramic samples showed the same series of narrow bands at 543, 551, 555, 572, 583, 594, 614, and 639 nm as the yttrium oxide spectra. The existence of these luminescence bands, which correspond to the emission of the ...0...0>-Y=O radical, and the absence of the emission lines of the ...0...0>-Sc=O radical indicate that yttrium ions, due to their larger radius, are the first that are displaced to the surface of crystallites in these systems, which is accompanied by the formation of the second phase in subsurface layers.