Abstract
Complex vapor compounds of the form MLnl4, where M is an alkali metal ion and Ln is a lanthanide or another trivalent ion, play an important role in metal halide arc lamps. Such compounds may be the dominant species in the vaporization process and increase the density of desired radiative species in discharge medium. Data are reported from a number of such systems obtained by mass spectroscopic, optical adsorption, vapor transport and lamp characteristic measurements.
