Synthesis, characterization of new Bi3+ containing apatites: Formation of red emitting phosphors by Eu3+ incorporation

• Published in: Journal of solid state chemistry 2017-10, Vol.254, p.138-143
• Main Authors: Pokhriyal, Meenakshi, Gupta, Akanksha, Uma, S.
• Format: Article
• Language: English
• Subjects: Apatite; Bismuth; Luminescence; Phosphosilicates
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2017.07.005

Single phase phosphosilicates, Ca7Bi3(PO4)5(SiO4)O2, Ca6Bi4(PO4)3(SiO4)3OF and Ca8Bi2(PO4)4(SiO4)2F2 have been synthesized and characterized by powder X-ray diffraction (PXRD), Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy. The charge balanced stoichiometries in the present investigation derived out of cationic and anionic variations lead to the formation of apatites with high Bi3+ content. PXRD Le Bail refinements were carried out in space group P63 (No. 173) instead of P63/m. Eu3+ substitution has been carried out to append luminescence property to the lattice. Investigation of Eu3+ luminescence revealed emission features consistent with its presence in the lower symmetry (6c) and the higher symmetry (2b) sites. The CIE coordinates of the Eu3+ doped (5mol%) apatite samples resulted in red emission. Usage of Bi3+ containing apatites (Ca7Bi3(PO4)5(SiO4)O2, Ca6Bi4(PO4)3(SiO4)3OF and Ca8Bi2(PO4)4(SiO4)2F2) as host lattices for Eu3+ incorporation resulted in red emitting phosphors irrespective of the apatite stoichiometry. [Display omitted] •Synthesized new Bi3+ containing phosphosilicate apatites.•High Bi3+ containing apatites by suitable cationic and anionic variations.•Successful Eu3+ substitution to append luminescence property to the lattice.