Neodymium: the essentials
Neodymium is present in misch metal to the extent of about 18%. The metal has a bright silvery metallic lustre. Neodymium is one of the more reactive rare-earth metals and quickly tarnishes in air, forming an oxide that spalls off and exposes the metal to further oxidation. It is one of the rare earth metals.
This sample is from The Elements Collection, an attractive and safely packaged collection of the 92 naturally occurring elements that is available for sale.
Neodymium: historical information
In 1885 von Welsbach separated didymium, an extract of cerite, into two new elemental components, neodymia and praseodymia, by repeated fractionation of ammonium didymium nitrate. While the free metal is a component of misch metal, (a pyrophoric alloy for lighter flints), the element was not isolated in relatively pure form until 1925.
Neodymium around us Read more »
Neodymium has no biological role.
Neodymium is never found in nature as the free element. Neodymium is found in the ores monazite sand [(Ce, La, etc.)PO4] and bastn°site [(Ce, La, etc.)(CO3)F], ores containing small amounts of all the rare earth metals. It is difficult to separate from other rare earth elements.
|Location||ppb by weight||ppb by atoms||Links|
|Human||(no data) ppb by weight||(no data) atoms relative to C = 1000000|
Physical properties Read more »
Heat properties Read more »
- Melting point: 1297 [1024 °C (1875 °F)] K
- Boiling point: 3373 [3100 °C (5612 °F)] K
- Enthalpy of fusion: |203| kJ mol-1
Crystal structure Read more »
The solid state structure of neodymium is: hcp (hexagonal close-packed).
Neodymium: orbital properties Read more »
Neodymium atoms have 60 electrons and the shell structure is 184.108.40.206.8.2. The ground state electronic configuration of neutral Neodymium is [Xe].4f4.6s2 and the term symbol of Neodymium is 5I4.
- Pauling electronegativity: 1.14 (Pauling units)
- First ionisation energy: 533.1 kJ mol‑1
- Second ionisation energy: 1040 kJ mol‑1
Isolation: neodymium metal is available commercially so it is not normally necessary to make it in the laboratory, which is just as well as it is difficult to isolate as the pure metal. This is largely because of the way it is found in nature. The lanthanoids are found in nature in a number of minerals. The most important are xenotime, monazite, and bastnaesite. The first two are orthophosphate minerals LnPO4 (Ln deonotes a mixture of all the lanthanoids except promethium which is vanishingly rare) and the third is a fluoride carbonate LnCO3F. Lanthanoids with even atomic numbers are more common. The most comon lanthanoids in these minerals are, in order, cerium, lanthanum, neodymium, and praseodymium. Monazite also contains thorium and ytrrium which makes handling difficult since thorium and its decomposition products are radioactive.
For many purposes it is not particularly necessary to separate the metals, but if separation into individual metals is required, the process is complex. Initially, the metals are extracted as salts from the ores by extraction with sulphuric acid (H2SO4), hydrochloric acid (HCl), and sodium hydroxide (NaOH). Modern purification techniques for these lanthanoid salt mixtures are ingenious and involve selective complexation techniques, solvent extractions, and ion exchange chromatography.
Pure neodymium is available through the reduction of NdF3 with calcium metal.
2NdF3 + 3Ca → 2Nd + 3CaF2
This would work for the other calcium halides as well but the product CaF2 is easier to handle under the reaction conditions (heat to 50°C above the melting point of the element in an argon atmosphere). Excess calcium is removed from the reaction mixture under vacuum.
Neodymium isotopes Read more »
Neodymium isotopes are used in a variety of scientific applications. Nd-142 has been used for the production of short-lived Tm and Yb isotopes. Nd-146 has been suggested for the production of Pm-147 which can be used as a source for radioisotopic power generation. Several Nd isotopes have been used for the production of other Pm isotopes. Finally, Nd-150 has been used to study double beta decay.
|142Nd||141.907719 (4)||27.2 (5)||0|
|143Nd||142.909810 (4)||12.2 (2)||7/2||-1.065|
|144Nd||143.910083 (4)||23.8 (3)||0|
|145Nd||144.912570 (4)||8.3 (1)||7/2||-0.656|
|146Nd||145.913113 (4)||17.2 (3)||0|
|148Nd||147.916889 (4)||5.7 (1)||0|
|150Nd||149.920887 (4)||5.6 (2)||0|