Crystal structure and photoluminescence of Tb3+-activated Ba3InB3O9

Subsolidus phase equilibrium of BaO-In2O3-B2O3 system has been investigated mainly by solid-state reaction technique and powder X-ray diffraction method. There are 15 definite three-phase regions under present experimental conditions. Two ternary compounds, Ba3InB9O18 and Ba3InB3O9 were found and confirmed in this system. Crystal structure of Ba3InB3O9 was determined from X-ray powder diffraction data using Rietveld method. It crystallizes in space group R (3) over bar with six formula units of a cell with a = 12.7713(4)angstrom, c=9.3950(2)angstrom and V = 1327.09(8)angstrom(3). Coordination surrounding of B-O in this structure, [BO3](3-) group, was confirmed by infrared absorption spectrum of Ba3InB3O9. Ba3In1-xTbxB3O9 (x = 0.1-0.5) phosphors exhibited green emission at about 543 nm with 370 nm light excited. There is neither emission from D-5(3) level nor concentration quenching observed in the case of Ba3InB3O9:Tb3+, which can be explained from the crystal structural features of the matrix Ba3InB3O9. Chemical stabilization, simple preparation, and luminescence characteristics make phosphors Ba3InB3O9:Tb3+ have potential applications in white light-emitting diodes. (C) 2011 Elsevier B.V. All rights reserved.