Stable isotopes of gadolinium available from ISOFLEX
|Isotope||Z(p)||N(n)||Atomic Mass||Natural Abundance||Enrichment Level||Chemical Form|
Gadolinium was discovered by Jean de Marignac in 1880. It is named for gadolinite, one of the minerals in which it was found, which was in turn named for chemist Johan Gadolin.
A colorless or light yellow lustrous metal, gadolinium occurs in a hexagonal close-packed crystalline form, known as alpha-gadolinium, which transforms to a body-centered cubic allotropic form, beta-gadolinium, when it reaches 1262 ºC. It exhibits a high degree of magnetism, especially at lower temperatures. Its salts are colorless. It has a vapor pressure of 9.0 torr at 1800 ºC. It also has superconductive properties. It is combustible and burns in air to form the oxide. It reacts slowly in water, is soluble in dilute acid, and is insoluble in water. All of its compounds are trivalent. Although the metal is stable in air at ordinary temperatures, it burns in air when heated to 150-180 ºC. Gadolinium is a strong reducing agent. It reduces oxides of several metals such as iron, chromium, lead, manganese, tin and zirconium into their elements. It burns in halogen vapors above 200 ºC, forming gadolinium(III) halides.
The most important application of this metal is as control rod material for shielding in nuclear power reactors. Other uses are in thermoelectric generating devices, as a thermoionic emitter, in yttrium-iron garnets in microwave filters to detect low-intensity signals, as an activator in many phosphors, for deoxidation of molten titanium, and as a catalyst.
Properties of Gadolinium
|Standard state||Solid at 298 ºK|
|CAS Registry ID||7440-54-2|
|Group in periodic table||N/A|
|Period in periodic table||6 (Lanthanoid)|
|Block in periodic table||f-block|
|Melting point||1313 °C|
|Boiling point||3266 °C|
|Vaporization point||3266 ºC|
|Thermal conductivity||10.5 W/(m·K) at 298.2 ºK|
|Electrical resistivity||134.0 µΩ·cm at 25 ºC|
|Specific heat||0.230 J/g mol at 20 ºC|
|Heat of vaporization||305 kJ·mol-1 at 3266 ºC|
|Heat of fusion||10 kJ·mol-1|
|Density of liquid||7.4 g/cm3 at 1313 °C|
|Density of solid||7.90 g/cm3|
|Electron configuration||[Xe]4f75d16s2 (partially filled f orbital)|
|Common oxidation state||+3|