A novel transparent amorphous LaGaO3–Nb2O5 sphere with high refractive indices fabricated by containerless solidification

Abstract

A series of novel transparent and amorphous spheres (1-x)LaGaO3-xNb2O5 (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.625, 0.650, 0.675) with high refractive indices were successfully synthesized through containerless solidification. In the range of 0 ≤ x ≤ 0.675, transparent samples diametered about 2–4 mm were produced. The glass transition temperature Tg and the crystal onset temperature Tx first rose and then reduced with rising x. The difference between Tg and Tx was ΔT = Tx - Tg. The ΔT curve exhibited two peaks at x = 0.2 and x = 0.6, with the maximum ΔT values of approximately 107 °C and 108 °C respectively. The refractive indices of the fabricated amorphous materials ranged from 2.00 to 2.45 with increasing x from 0.1 to 0.675 in the visible light range. The transmittances ranged from 82% to 71% with increasing x from 0 to 0.5 in the visible light range. Raman scattering spectra showed that the maximum phonon energy increased from 782 cm−1 to 815 cm−1 with rising x from 0 to 0.5. The as-prepared amorphous materials pave the way for developing novel optical components.