Nanostructured (Y1-xGdx)2O 3:Eu3+ powders obtained through aerosol synthesis

Abstract

In this study, nanophase, spherical, polycrystalline (Y 1-xGdx)2O3:Eu3+phosphor particles were synthesized from aerosols of corresponding nitrate solutions, ultrasonically generated at 1.3 MHz frequency, and thermally decomposed at 900 and 1100°C. Structural and morphological analyses done by X-ray powder diffraction (XRPD) and transmission electron microscopy analysis (TEM) implied the formation of non-aggregated spherical, submicronic particles with smooth particle surfaces and filled morphology. The phase development and structural changes, determined using the Topas program, implied a nanocrystalline inner structure (crystallites < 20 nm), that was also confirmed by SAED analysis. A bcc Ia-3 cubic phase was identified in all as-prepared samples, apart from the mixed oxide with the gadolinium content > 75%, where the existence of a secondary, fee Fm-3m cubic phase is determined. Only Ia-3 cubic phase was identified in thermally treated samples (1100 °C), while the powder morphological features were maintained, followed by increase in powder crystallinity and phase homogeneity. Functional properties were analyzed by means of photoluminescent analysis. Emission spectra showed typical Eu 3+ 5D0→7Fi (i = 0, 1, 2, 3, 4) transitions with the dominant red emission peak at 611 nm.