| 摘要 |
<p>LANTHANUM-GADOLINIUM PHOSPHATE X-RAY PHOSPHORS X-ray phosphor compositions of the formula: La1-XGdxPO4 wherein x is from about 0.01 to about 0.5, when incorporated into conventional x-ray intensifying screen, improve the resolution, of the image in the resulting film. The lanthanum gadolinium phosphate under x-ray excitation has a line emission with a peak at about 312 nanometers. A solid state process wherein the respective rare earth oxides and ammonium orthophosphate are first heated together under controlled temperature conditions and then reheated with a suitable alkali metal phosphate flux', followed by a nitric acid treatment, enables the production of materials having particle sizes suitable for x-ray screens . Use of the lanthanum-gadolinium phosphate in screens in conjunction with conventional base films effectively eliminates distortion resulting from cross-over.</p> |
