Function of spinel related phosphors and its application

本研究的目的是从磁铅石结构等低维结构的观点出发，探讨具有高荧光强度的VFD（真空荧光显示器）用新型荧光粉的材料设计。通常，VFD用发光荧光粉应要求保持一定的导电性，因为要防止某些空间电荷。在此背景下，我们还研究了以稀土金属为发光中心，以Ti^<4+>和Sn^<4+>为基质的新型烧绿石型氧化物的制备，并成功地制备了以Eu^<3+>和Pr^<3+>为固溶体的新型VFD荧光粉。通过调节发光中心离子的浓度，用阴极荧光技术观察到了较强的荧光发射，并确定了产物为单相烧绿石。根据XRD数据，准确地确定了其结构为层状尖晶石结构，其中BO_3和AlO_4块体更适合于147nm激发（即，气体激励）。

The purpose of this project is to examine the material design of novel phosphors for VFD (Vacuum Fluorescence Display) with high fluorescence intensity from a viewpoint of structural low-dimensionality such as magnetoplumbite structure etc. Generally, a luminous phosphor for VFD should be requested to keep some electric conductivity owing to the prevention of some space charges. In this context, we also investigated the fabrication of novel pyrochlore type oxides which consisted of rare earth metals as luminous centers and host lattice with Ti^<4+> and Sn^<4+> ions being semiconductive.As a result, we succeeded to make novel phosphors in the solid solution of Eu^<3+> and Pr^<3+> pyrochlores for VFD. The resulting compounds were identified as single phase of pyrochlore and observed the intense emission by a cathodeluminescence technique after adjusting the suitable concentration of luminous center ions.On the other hand, CaAl_2B_2O_7;Eu^<2+> phosphor was newly synthesized as PDP's (Plasma Display Panel's) use. According to the XRD data, the structure was precisely determined to a layered spinel structure with BO_3 and AlO_4 blocks which were more available for the 147nm-excitation(i.e., Xe gas excitation).