Rare-earth Materials: yttrium oxide, indium oxide, Cerium oxide, etc.
Cerium Fluoride(CeF3) is a good scintillation crystal with high density
and short decay time.
The filling up of 4f orbitals begins with Cerium(Z = 58) and ends at lutetium(Z = 71).
Cerium tungsten electrode, which is also known as WC electrode, contains a minimum
of 97.30% tungsten and 1.80 to 2.20% Cerium.
Like thorium, this Cerium tungsten electrode is most appropriate for welding carbon
and stainless steels, nickel alloys and titanium, making it an ideal replacement for 2% thoriated electrodes.
Cerium tungsten electrode has become popular
in such applications as orbital tube and pipe manufacturing, thin sheet metal work or jobs where small and delicate parts are welded by virtue of its excellent arc starts at low amperages.
Cerium tungsten electrode is not suitable for applications under high current condition, because under that condition the oxides will rapidly migrate to the heat zone, namely the top of the
electrode welding point, which will damage the evenness of the oxides.
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.