| abstract |
A mixture of starting materials, corresponding to an oxide composition within an area of the ternary diagram for (Hf,Zr)O2, A2O, P2O5 formed by connecting end member points defined by the molar compositions: 45 (Hf,Zr)O2 - 10 A2O - 45 P2O5; 45 (Hf,Zr)O2 - 45 A2O - 10 P2O5; and 10 (Hf,Zr)O2 - 45 A2O - 45 P2O5, reacts to form large single crystalline essentially hexagonal particles of a new compound (Hf1-xZrx)3-yA4y (PO4)4, and an aqueous-soluble second phase removable by washing. The large single crystalline hexagonal particles are useful as the luminescent material in x-ray intensifying screens, with band emission which overlaps at least partially the absorption edge of an x-ray film base to give good image resolution without crossover distortion. |