A phosphor comprises europium, at least two alkaline-earth metals, and at
least a Group-13 metal. In one embodiment, the phosphor has a formula
selected from the group consisting of
Sr.sub.4-a-zA.sub.aEu.sub.zD.sub.12O.sub.22 and
Sr.sub.4-a-zA.sub.aEu.sub.zD.sub.14O.sub.25; wherein A is at least an
alkaline-earth metal other than strontium; D is an element selected from
the group consisting of Group-13 metals, group-3 metals, and rare-earth
metals; 00. The phosphor can
be used in light sources and displays.