Bivalent europium-activated barium aluminate phosphor and low mercury vapor discharge lamp provided with a phosphor

摘要

A luminescent screen provided with a luminescent layer (4) disposed on a support (1) and containing an alkaline earth metal aluminate activated by bivalent europium. The alkaline earth metal is barium which may be replaced up to 25 mol. % by strontium. The aluminate has a crystal structure, the X-ray powder diagram of which corresponds or substantially corresponds to the diagram given in Table I of the description, while the ratio of alkaline earth metal to aluminium in the aluminate has a value of 1:5 to 1:10. An advantageous use of such a luminescent screen is found in low-pressure mercury vapor discharge lamps.