Praseodymium, Pr

Praseodymium is a chemical element that has the symbol Pr and atomic number 59.

Praseodymium is a soft silvery metal in the lanthanide group. It is somewhat more resistant to corrosion in air than europium, lanthanum, cerium, or neodymium, but it does develop a green oxide coating that spalls off when exposed to air, exposing more metal to oxidation. For this reason, praseodymium should be stored under a light mineral oil or sealed in glass.

Technical Data
Symbol Pr Density (25°C)/gcm3 6.475
Atomic number 59 Melting point / °C 935
No. of naturallyoccurring isotopes 1 Boiling point / °C -3020
Atomic weight 140.9077 ΔHfus/kJmol-1 11.3(+/-2.1)
Outer electron configuration 4f36s2 ΔHvap/kJmol-1 331
Metal radius(6-coordinate)/pm 182.4 ΔHf(monoatomic gas)/kJmol-1 356
Ionic radius(6-coordinate)/pm IV 85 ΔH(hydration Ln3+)/kJmol-1 3413
Ionic radius(6-coordinate)/pm III 99 Ionization energy/kJmol-1 I 522
Eo(M4+(aq)+e- →M3+(aq))/V 2.860* Ionization energy/kJmol-1 II 1018
Eo(M3+(aq)+e- →M(s))/V -2.462 Ionization energy/kJmol-1 III 2090
Electrical resistivity(25 oC) μohm cm 68    
Evaporation Techniques
Temperature (oC) @Vap. Pressure Techniques Remarks
10-8 Torr 10-6 Torr 10-4 Torr Electron Beam Crucible Coil Boat
800 950 1150 Good - - Tantalum  

Evaporation Materials
P5-5000-M Ingot (Please ask for sizes)
P5-5001-M pieces 12mm and smaller

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

Foil
P5-3003-F 0.004" (0.1mm)
P5-3007-F 0.008" (0.2mm)
Powder
P5-10000-P -40 mesh (under oil)
P5-10001-P -325 mesh
Rods
P5-2000-R 0.250" (6.35mm)
P5-2001-R 0.500" (12.7mm)
Sheet
P5-4001-S 0.015" (0.38mm)
P5-4002-S 0.020" (0.5mm)
P5-4003-S 0.030" (0.76mm)
P5-4004-S 0.040" (1mm)