Cerium, Ce

Cerium is a silvery metal, belonging to the lanthanide group. It resembles iron in color and luster, but is soft, and both malleable and ductile. Cerium has the longest liquid range of any non-radioactive element: 2648 °C (795 °C to 3443 °C) or 4766 °F (1463 °F to 6229 °F). (Thorium has a longer liquid range.)

Although cerium belongs to chemical elements group called rare earth metals, it is in fact more common than lead. Cerium is available in relatively large quantities (68 ppm in Earth’s crust). It is used in some rare-earth alloys.

Among rare earth elements only europium is more reactive. It tarnishes readily in the air. Alkali solutions and dilute and concentrated acids attack the metal rapidly. Cerium oxidizes slowly in cold water and rapidly in hot water. The pure metal can ignite if scratched.

Cerium(IV) (ceric) salts are orange red or yellowish, whereas cerium(III) (cerous) salts are usually white or colorless. Both oxidation states absorb ultraviolet light strongly. Cerium(III) can be used to make glasses that are colorless, yet absorb ultraviolet light almost completely. Cerium can be readily detected in rare earth mixtures by a very sensitive qualitative test: addition of ammonia and hydrogen peroxide to an aqueous solution of lanthanides produces a characteristic dark brown color if cerium is present.

Technical Data
Symbol Ce Density (25°C)/gcm-3 Melting point /°C 6.776
Atomic number 58 Boiling point /°C 804
No. of naturally occurring isotopes 4 ΔHfus/kJmol-1 -3470
Atomic weight 140.12 ΔHvap/kJmol-1 5.2(+/-1.2)
Outer electron configuration 4f35d16s2 ΔHf(monoatomic gas)/kJmol-1 398
Ionization energy/kJmol 541 ΔHf(monoatomic gas)/kJmol-1 419
II 1047 Electrical resistivity 3370
III 1940 (25°C)/μohm cm 75
Metal radius(6-coordinate)/pm 181.8 Eo(M4+(aq)+e- →M3+(aq))/V 1.61
Ionic radius(6-coordinate)/pm IV 87 Eo(M3+(aq)+3e- →M(S))/V -2.483
Ionic radius(6-coordinatc)/pm III 102    
Evaporation Techniques
Temperature (oC) @Vap. Pressure Techniques Remarks
10-8 Torr 10-6 Torr 10-4 Torr Electron Beam Crucible Coil Boat
970 1150 1380 Good Al2O3 & Vitreous Graphite Tungsten Tungsten & Tantalum Films oxidize easily.

Evaporation Materials
C4-5001-M Ingot (Please ask for sizes)
C4-5002-M pieces 12mm and smaller
Foil
C4-3003-F 0.004" (0.1mm)
C4-3007-F 0.008" (0.2mm)
Powder
C3-10000-P -40 mesh
C3-10001-P -100 mesh
C3-10002-P -325 mesh
Rods
C4-2000-R 0.250" (6.35mm)
C4-2001-R 0.500" (12.7mm)
Sheet
C4-4003-S 0.020" (0.5mm)
C4-4005-S 0.040" (1.0mm)
C4-5006-S 0.125" (3.175mm)
C4-5007-S 0.250" (6.35mm)