Symbol Eu. A soft silvery metallic element belonging to the
lanthanoids; a.n.63 r.a.m 151.96; r.d 5.245 (20°C);
m.p 822 °C; b.p 1597 °C. It was
discovered by Sir William Crookes in 1889.
It occurs in small quantities
in bastanite and monazite. Two stable isotopes occur
naturally europium-151 & europium-153 both of
which are neutron absorbers.
Europium alloys have
been tried for nuclear-reactor parts but until recently
the metal has not been available in sufficient quantities.
It is used in the form of the oxide in phosphorus for