Influence of anionic substitutions on the nonlinear-optical and luminescent properties of Ca 9.75 Eu 0.5 (VO 4 ) 7

Abstract

New anion-substituted vanadates Ca 9.75±δ Eu 0.5 (XO 4 ) 0.1 (VO 4 ) 6.9 (X = As 5+ , S 6+ , Sb 5+ , Ta 5+ , Mo 6+ , Te 4+ ) have been synthesized by high-temperature solid-state method. Crystal structure, nonlinear optical properties, photoluminescence excitation (PLE) and emission (PL) spectra are investigated. The maximum second harmonic generation (SHG) value is achieved for the compound with Te 4+ , where the intensity increases by 6 times. For all samples, the most intense luminescence band is in the region of 613.5 nm with excitation at 395 nm. The maximum luminescence intensity is observed for vanadate with Te 4+ , and the minimum for vanadate with Mo 6+ . The presence of at least two bands in the region of the 5 D 0 → 7 F 0 transition indicates low symmetry of Eu 3+ polyhedra, which occupy at least two positions in the structure. The CIE color coordinates for all compositions except the initial composition are poorly distinguishable. Experimental data show that Ca 9.75±δ Eu 0.5 (XO 4 ) 0.1 (VO 4 ) 6.9 phosphors are promising candidates for use in solid-state lighting.