The phosphors based on phosphate host matrices have become
the subject of great interest for an extensive investigation due
to their wide applications in lighting and displays. As an example,
LaPO4:Tb3+ has been considered as an excellent commercial
green phosphor that has been widely applied in the development
of fluorescent lamps, cathode ray tubes, field emission displays and
plasma display panels. Accordingly, some research work has been
carried out to improve its properties [1,2]. LaPO4:Eu3+ has been
identified as another good phosphate phosphor which displays an
intense red emission under an ultraviolet source [3,4]. It is commercially
valuable to decrease the crystallization temperature and
replace partial expensive lanthanum oxides by relatively cheaper
alkali and alkaline earth metal salts with a negligible influence on
the photoluminescence properties.