Novel Ni-doped Al 2 TiO 5 emerald green ceramic pigments were successfully synthesized for the first time. Several characterization techniques (XRD, XPS , SEM, TEM, UV–Vis, and automatic colorimeters) were used to determine the phase composition and stability of the pigments, as well as the valence state of the doped nickel ion . The results show that nickel ion replaces the Al 3+ in the aluminum titanate lattice in the form of Ni 2+ , which reduces the distortion of the octahedral structure. Ni-doping of the aluminum titanate lattice produces an excellent coloring effect and significantly promotes the synthesis and stabilization of aluminum titanate. The novel pigments have excellent color stability while maintaining exceptional coloring performance and thermal stability in a base glaze synthesized at 1200 °C. These pigments show considerable potential for high-temperature applications.
Xuejiao Wang,Sihan Yang,Feng Jiang,Jiantong Wang,Changshuai Gong,Ji-Guang Li
Cr3+-activated near-infrared (NIR) phosphors are the most promising materials for commercialization. However, the emission of most Cr3+-activated phosphors is typically located in the NIR-I region and achieving luminescence towards the NIR-II region (>900 nm) via Cr3+ doping remains challenging. This study reports a novel Cr3+-activated NaBaScSi2O7 phosphor that exhibits broadband NIR emission centred at 974 nm with a full width at half maximum of 140 nm under 493 nm blue light excitation. The emission wavelength exceeds that of most Cr3+-activated NIR phosphors. The underlying mechanism for the encouraging phenomenon is attributed to the strong charge polarisation arising from the intrinsic local coordination environment of the Cr3+ ions, as confirmed by charge differential density (CDD) and the electron localization function (ELF) analyses. The photoluminescence properties of phosphors were systematically investigated, and the performance of the fabricated NIR pc-LED device was evaluated for night vision and non-invasive imaging. Notably, the NaBaScSi2O7 phosphor displayed a bright green colour with excellent colour properties and its potential as a stable green ceramic pigment was explored.