Explorations of highly birefringent materials in the vanadium oxyfluoride–iodate system by fluoride ion modulation

Two new vanadium oxyfluoride–iodate birefringent materials, Sr[VO 2 F(IO 3 ) 2 ] and Sr 3 F 2 (VO 2 F 4 )(IO 3 ), have been successfully synthesized. These two compounds exhibit high birefringences with values of 0.250 and 0.406 at 550 nm, respectively.