Author: Jan Scholten
10.0 Gadolinium physical
Gadolinium is a silvery white or light yellow, malleable and ductile rare earth metal with a metallic luster. It crystallizes in hexagonal, close-packed alpha form at room temperature; when heated to 1508 K, it transforms into its beta form, which has a body-centered cubic structure.
Unlike other rare earth elements, gadolinium is relatively stable in dry air; however, it tarnishes quickly in moist air and forms a loosely adhering oxide that spalls off and exposes more surface to oxidation. Gadolinium reacts slowly with water and is soluble in dilute acid.
Atomic Number: 64.
Discovery: 1880 by J.C. Galissard de Marignac at Geneva, Switzerland.
Name: the mineral gadolinit.
Toxicology: Mildly by ingestion, and is a skin and eye irritant.
It is a suspected tumorigen. It stimulates metabolism.
Ore: gadolinite, monazite and bastnasite
1. Becomes superconductive at 1 degree Kelvin.
2. GdOS + Tb is used in radar screens.
3. Gadolinium yttrium garnets, which have microwave applications.
4. Color television: phosphors for colour TV tubes.
5. Compact discs.
6. Computer memory.
7. Neutron absorber: secondary, emergency shut-down measure in some nuclear reactors, particularly of the CANDU type.
8. Metallurgy: as little as 1% of gadolinium improving the workability and resistance of iron, chromium and related alloys to high temperatures and oxidation.
9. Magnetic resonance imaging: solutions of organic gadolinium complexes are used as intravenous radiocontrast agents to enhance images in medical magnetic resonance imaging.
10. Gallium Gadolinium Garnet (Gd3Ga5O12) a material with good optical properties, and is used in fabrication of various optical components and as substrate material for magneto–optical films.
11. Masers: gadolinium ethyl sulfate, which has extremely low noise characteristics, may be used in the future.
12. Heat sensors: gadolinium’s high magnetic movement and low Curie temperature (which lies just at room temperature) suggest applications as a magnetic component for sensing hot and cold.