Cobalt, Co

Cobalt is a hard, lustrous, silver-grey metal, a chemical element with symbol Co. It is found in various ores, and is used in the preparation of magnetic, wear-resistant, and high-strength alloys. Its compounds are used in the production of inks, paints, and varnishes.

Cobalt is a silver or gray ferromagnetic metal. Pure cobalt is not found in nature, but compounds of cobalt occur naturally in many forms. Small amounts of it are found in most rocks, soil, water, plants, and animals. It is an element of atomic number 27. The Curie temperature is of 1388 K with 1.6~1.7 Bohr magnetons per atom. In nature, it is frequently associated with nickel, and both are characteristic ingredients of meteoric iron. Mammals require small amounts of cobalt which is the basis of vitamin B12. Cobalt-60, an artificially produced radioactive isotope of cobalt, is an important radioactive tracer and cancer-treatment agent. Cobalt has a relative permeability two thirds that of iron. Metallic cobalt commonly presents a mixture of two crystallographic structures hcp and fcc with a transition temperature hcp→fcc of 722 K. Cobalt has a hardness of 5.5 on the Mohs scale of mineral hardness.

Common oxidation states of cobalt include +2 and +3, although compounds with oxidation state +1 are also well developed.

Technical Data
Symbol Co Melting point/ °C 1495
Atomic number 27 Boiling point/ °C 3100
No. of naturally occurring isotopes 1 ΔHfus/kJmol-1 16.3
Atomic weight 58.9332 ΔHvap/kJmol-1 382
Electronic configuration [Ar]3d74s2 ΔHf(monoatomic gas)/kJmol-1 425 (+/-17)
Metal radius(12-coordinate)/pm 125 Electrical resistivity  
Ionic radius(6-coordinaie)/pm TV 53 (20°C)/ μohm cm 6.24
Ionic radius(6-coordinatc)/pm III 54.5(ls),61(hs) Electronegativity χ 1.8
Ionic radius) 6-coordinate)/pm II 65(ls).74.5(hs) (Is = low spin, hs = high spin)  
Density (20°C)/gcm-3 8.9    
Evaporation Techniques
Temperature (oC) @Vap. Pressure Techniques Remarks
10-8 Torr 10-6 Torr 10-4 Torr Electron Beam Crucible Coil Boat
850 990 1200 Excellent Al2O3 - Tungsten & Niobium Alloys with refractory metals.

Evaporation Materials
C7-5000-M Ingot (Please ask for sizes)
C7-5001-M pellets 6mm diameter x 3mm long
C7-5002-M pellets 6mm diameter x 6mm long
C7-5003-M pieces 1-3mm
C7-5004-M pieces 12mm and smaller
C7-5009-M pellets 3mm diameter x 3mm long

The foils are available in either rectangular or circular shape. Please enter width and length or diameter of the required foil.

Foil
C7-3003-F 0.004" (0.1mm)
C7-3007-F 0.008" (0.2mm)
Powder
C7-10000-P -50 mesh
C7-10001-P -100 mesh
C7-10004-P -325 mesh
C7-10005-P 15 microns
Rods
C7-2000-R 0.0625" (1.58mm)
C7-2001-R 0.125" (3.175mm)
C7-2002-R 0.250" (6.35mm)
C7-2003-R 0.375" (9.5mm)
Sheet
C7-4002-S 0.020" (0.5mm)
C7-4004-S 0.040" (1mm)
C7-4006-S 0.060" (1.5mm)
C7-4008-S 0.125" (3.175mm)
Wire
C7-1000-W 0.005" (0.127mm)
C7-1003-W 0.008" (0.2mm)
C7-1007-W 0.020" (0.5mm)
C7-1009-W 0.040" (1mm)
C7-1013-W 0.080" (2mm)