ISSN:2321-6212
N. Akiyama, H. Kuwahara, H. Kuroe, H. T. Hintzen and K. Itatani
Sophia University, Japan
Delft University of Technology, The Netherlands
Posters & Accepted Abstracts: Res. Rev. J Mat. Sci.
The conditions for the fabrication of transparent glass body in the Li2O-ZnO-B2O3-P2O5-CaF2 system were examined by a pressureless firing and subsequent oxygen-supplied hot isostatic pressing (O2-HIP). The starting glass was prepared by melting the mixture of LiOH, ZnO, H3BO4, H3PO4 and CaF2 at 1100�ºC in air, followed by quenching on copper plates cooled by liquid nitrogen. The glass powder compact was pressurelessly-fired at 370�ºC for 1 h in order to remove the open pores, and the subsequent O2-HIP treatment at 370 �ºC for 24 h under the pressure of 130 MPa made the clear light transmission possible, regardless of the formation of Ca2P2O7 on the surface. The glass body obtained by firing at 370��C for 1 h and the subsequent O2-HIP treatment at 370 �ºC for 24 h was hydrothermally-treated in water at 100��C for 1 h, and found that the mass loss of this body was as low as 0.25%, showing excellent water resistance. When the oxynitride phosphors, i.e., blue-emitting (La0.96Ce0.04)3Si8O4N11 and yellow-emitting (Ca0.97Eu0.03) Si2O2N2, were encapsulated into the glass, no peak shifts in the emission/excitation spectra were found, which demonstrated that no significant degradation of phosphors has occurred during the encapsulation operation. Pseudo-white light emission was observed by the equi-mass addition (total amount: 3 mass%) of (La0.96Ce0.04)3Si8O4N11 and (Ca0.97Eu0.03)Si2O2N2. Overall, the transparent glass body could be fabricated by the pressureless firing and subsequent O2-HIP treatment, and the phosphors were encapsulated into the glass without significant degradation.
Nanako Akiyama is a student of Sophia graduate school. Her research interest is the luminescence properties of oxide, oxynitride and nitride phosphors, and the encapsulation technique of the phosphors in the glass.