16 articles
Cerium
Cerium (symbol Ce, atomic number 58) is a silvery lanthanide metal, the most abundant rare earth element, identified in 1803 and named after the asteroid Ceres.
Erbium
Erbium is a chemical element with the symbol Er and atomic number 68, a soft silvery lanthanide metal used in fiber optic amplifiers, dermatology lasers, and pink glass.
Gadolinium
Gadolinium, element 64 with symbol Gd, is a silvery lanthanide metal with the highest thermal neutron capture of any element and key use in MRI contrast agents.
Holmium
Holmium is a silvery chemical element with symbol Ho and atomic number 67, a rare earth metal with the strongest magnetic moment of any element.
Lanthanide contraction
The lanthanide contraction is the steady decrease in atomic and ionic radii of the lanthanide elements from lanthanum to lutetium, caused by poor shielding by 4f electrons.
Lanthanum
Lanthanum is a soft, silvery-white metallic element with atomic number 57, the first of the lanthanide series, discovered by Carl Gustav Mosander in Sweden in 1839.
Lutetium
Lutetium, also called cassiopeium, is a silvery-white metal, atomic number 71 and the heaviest lanthanide, discovered in 1907 and named after Lutetia, the Latin name for Paris.
Neodymium
Neodymium is a chemical element with atomic number 60, a silvery lanthanide metal discovered in 1885 and best known as the key ingredient of the strongest permanent magnets.
Praseodymium
Praseodymium is a soft, silvery lanthanide metal with atomic number 59, best known as a substitute for neodymium in magnets and as part of didymium glass.
Rare-earth element
The rare-earth elements, or rare earths, are a group of 17 chemically similar metals: the 15 lanthanides plus scandium and yttrium, used in magnets, phosphors, and catalysts.
Rare-earth ion
A rare-earth ion (REI) is a charged lanthanide, scandium, or yttrium ion embedded in a host crystal, whose shielded 4f electrons give narrow, stable optical transitions used in quantum memories.
Samarium
Samarium (symbol Sm, atomic number 62) is a silvery rare-earth metal isolated in 1879, best known for samarium-cobalt magnets and for dating the oldest rocks on Earth.
Scandium
Scandium, symbol Sc and atomic number 21, is a silvery lightweight transition metal discovered in 1879 by Lars Fredrik Nilson, confirming Mendeleev's prediction of ekaboron.
Terbium
Terbium, element 65, is a silvery lanthanide metal isolated in 1843 by Carl Gustav Mosander and named after Ytterby, Sweden, best known for green phosphors and the Terfenol-D alloy.
Thulium
Thulium is a chemical element with symbol Tm and atomic number 69, the least abundant stable rare-earth metal, used mainly as a dopant in surgical lasers.
Yttrium
Yttrium is a chemical element with symbol Y and atomic number 39, a silvery metal grouped with the rare earths and used in phosphors, lasers, and superconductors.