J. Shi et al., THE FORMATION OF A ZIRCONATE PHASE WITHIN THE EMISSION MIX FOR LOW-PRESSURE HG-AR DISCHARGE LAMPS, Journal of the Illuminating Engineering Society, 24(1), 1995, pp. 100
It was discovered in the early 1950s that vaporization of barium from
the cathode in a fluorescent lamp can be reduced tremendously with the
addition of zirconium oxide to the coating mix. The lamp industry has
been using this added material (Zr or ZrO2) since then. However, the
reason for this improvement is poorly understood. In this paper, it is
shown by using x-ray diffraction that a barium-strontium zirconate ph
ase forms under conditions that mimic different lamp operating charact
eristics. The formation of this compound may be related to the observe
d improvements in lamp properties.