Synthesis and characterization of calcium lanthanum sulfide via a wet chemistry route followed by thermal decomposition

Abstract

Calcium lanthanum sulfide (CaLa₂S₄) has been extensively studied as a promising candidate for advanced infrared optical ceramics. In the present research, we report the successful synthesis of CaLa₂S₄ via a wet chemistry method followed by thermal decomposition. CaLa₂S₄ precursor material was first prepared by a facile ethanol-based wet chemical single-source precursor route. The precursor was then thermally decomposed in argon at high temperature to form CaLa₂S₄. The phase composition and morphology of the synthesized CaLa₂S₄ powder were confirmed and observed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), respectively. Surface area and pore size analyses showed that the CaLa₂S₄ powder had a high specific surface due to a combined effect of small particle size and the existence of mesopores. Optical characterization revealed that the synthesized CaLa₂S₄ powder exhibited quantum size confinement and near-band-edge photoluminescence.