| abstract |
In a luminescent material which comprises a first component for luminescing red light under influence of incident optical radiation and a second component for luminescing in the spectral range from 520 to 560 nm, the second component includes a first phase of garnet crystallization system consisted of yttrium aluminate activated by trivalent cerium and determined by the general structural formula Y3-aCeaAl5O12, wherein 0.0003<a<0.1, and a second phase of hexagonal crystallization system of general structural formula LabCe1-bAl11O18, wherein O<b<1, and the second phase is present in an amount ranging from the amounts detectable by means of X-ray diffractometry to the double amount of the first phase. In a low-pressure or high-pressure mercury vapor gas discharge lamp, comprising a hermetically sealed discharge vessel including at least two electrodes for generating a gas discharge process, an inner surface is covered by a luminescent material, comprising the two phases mentioned above, wherein the composition of the two phases is determined by the general structural formula Y3-aCeaAl5O12+xLabCe1-bAl 11O18, wherein O<x<2, 0.0003<a<0.1 and O<b<1 and the second phase is present in an amount ranging from the amounts detectable by means of X-ray diffractometry to the double amount of the first phase. |