Narrow-band red phosphors of high colour purity based on Eu3+-activated apatite-type Gd9.33(SiO4)6O2

A series of new red phosphors based on apatite-type gadolinium silicate host, Gd9.33−xEux(SiO4)6O2 (0.03 x < 1.87), have been synthesised and analysed.