Synthesis and Eu3+ luminescence in new oxysilicates, ALa3Bi(SiO4)3O and ALa2Bi2(SiO4)3O [A6-point double bond; length half of m-dashCa, Sr and Ba] with apatite-related structure

New oxysilicates with the general formula ALa3Bi(SiO4)3O and ALa2Bi2(SiO4)3O [A6-point double bond; length half of m-dashCa, Sr and Ba] are synthesized and characterized. Powder X-ray diffraction of these silicates show that they are isostructural with BiCa4(VO4)3O which has an apatite-related structure. Eu3+ luminescence in the newly synthesized oxysilicates show broad emission lines due to disorder of cations. The relatively high intense magnetic dipole transition 5D0→7F1 points to a more symmetric environment. The photoluminescence results confirm that the compounds have apatite-related crystal structure.