Crystal growth of Ca sub(3SiO) sub(4)Br sub(2: New photoluminescence bromosilicate host)

Single crystals of new bromosilicate compound Ca sub(3SiO) sub(4)Br sub(2 were grown out of high-temperature Ca) sub(2)SiO sub(4/CaBr) sub(2) melts by the slow cooling process. Colorless, transparent and flaky crystals of Ca sub(3SiO) sub(4)Br sub(2 were directly isolated from the final solid coagulation. The as-obtained crystals were investigated by energy dispersive X-ray spectrometer (EDS), scanning electron microscope (SEM) and polarized light microscope (PLM). The structure of the new Ca) sub(3)SiO sub(4Br) sub(2) compound was determined by single-crystal X-ray diffraction, and it crystallized in the triclinic system, space group P-1 with unit cell parameters a=8.0051(18) Aa, b=8.720(3) Aa, c=11.749(3) Aa, [alpha]=69.07(0)[deg], [beta]=89.98(0)[deg], [gamma]=75.46(0)[deg] and V=737.88(196) Aa[super]3, Z=3. Interestingly, a significant amount of Eu[super]2+ enters the Ca sub(3SiO) sub(4)Br sub(2 phase, and the Eu[super]2+-doped Ca) sub(3)SiO sub(4Br) sub(2) phosphor shows a strong blue emission band centered at 469 nm under 365 nm UV light, which demonstrates that Ca sub(3SiO) sub(4)Br sub(2:Eu[super]2+ is a promising blue phosphor for use in white light LEDs.)