Praseodymium is a component of didymium glass,
Praseodymium alloyed with nickel(PrNi5) has such a
Praseodymium compounds give glasses and enamels a yellow color.
Using classical separation methods, Praseodymium was always difficult to purify.
Doping Praseodymium in fluoride glass allows it to be used
Many of Praseodymium's industrial uses involve its ability to filter
Praseodymium has historically been a rare earth
whose supply has exceeded demand.
The name Praseodymium comes from the Greek prasinos(πράσινος), meaning"green", and didymos(δίδυμος),"twin.
Misch metal, used in making cigarette lighters,
contains about 5% Praseodymium metal.
Silicate crystals doped with Praseodymium ions have been used to slow
at sufficiently high loadings, Praseodymium glass is distinctly green rather than pure yellow.
Many of Praseodymium's industrial uses involve its ability to filter
yellow light from light sources.
Moser also blended Praseodymium with neodymium to produce"Heliolite" glass("Heliolit" in German),
which was more widely accepted.
Doping Praseodymium in fluoride glass allows it to be used
as a single-mode fiber optical amplifier.
Praseodymium oxide in solid solution with ceria or ceria-zirconia
has been used as an oxidation catalyst.
Praseodymium(IV) is a strong oxidant,
instantly oxidizing water to elemental oxygen(O2), or hydrochloric acid to elemental chlorine.
Praseodymium is a component of didymium glass,
which is used to make certain types of welder's and glass blower's goggles.
Silicate crystals doped with Praseodymium ions have been used to slow
a light pulse down to a few hundred meters per second.
In the 1930s it was found(Beck) that Praseodymium dioxide could be precipitated from KOH/NaOH eutectic melts,
by oxidation by electrochemistry, or by sodium chlorate.
However, as technology progresses, Praseodymium has been found possible to incorporate into neodymium-iron-boron magnets, thereby extending the supply of the much in demand neodymium.
Praseodymium alloyed with nickel(PrNi5) has such a
strong magnetocaloric effect that it has allowed scientists to approach within one thousandth of a degree of absolute zero.
However, as technology progresses, it has been found that Praseodymium can be incorporated into neodymium-iron-boron magnets, thereby extending the supply of the much in demand neodymium.
The first enduring commercial use of purified Praseodymium, which continues today,
is in the form of a yellow-orange"Praseodymium Yellow" stain for ceramics,
which is a solid solution in the zircon lattice.
However, a similar color could be achieved with colorants costing only a minute fraction of what Praseodymium cost in the late 1920s,
such that the color was not popular, few pieces were made, and examples are now extremely rare.
Much less abundant than the lanthanum and neodymium from which it was being separated(cerium having
long since been removed by redox chemistry), Praseodymium ended up being dispersed among a large number of fractions,
and the resulting yields of purified material were low.