摘要 |
Self-activated ultraviolet-emitting hafnium pyrophosphate phosphors. Up to about 20 mole percent of the hafnium may be substituted with one or more of zirconium, germanium and silicon. The phosphors, which may be excited by ultraviolet radiation, x-rays and electron beams, may be used as energy converters in photodevices. The phosphors may be prepared by heating a mixture of a hafnium compound, a phosphate (no added activator ions) and optionally compounds of one or more of zirconium, germanium and silicon, which are present in proportions up to about 25 mole percent of the hafnium present, at about 1000 DEG to 1300 DEG C in air. |