Tungsten, W

Tungsten, also called wolfram, is a chemical element that has the symbol W (German: Wolfram) and atomic number 74. A very hard, heavy, steel-gray to white transition metal, tungsten is found in several ores including wolframite and scheelite and is remarkable for its robust physical properties, especially the fact that it has the highest melting point of all the non-alloyed metals and the second highest of all the elements after carbon. The pure form is used mainly in electrical applications but its many compounds and alloys are widely used in many applications, most notably in light bulb filaments, in X-ray tubes (as both the filament and target), and in superalloys. Tungsten is the only metal from the third transition series that is known to occur in biomolecules.

Technical Data
Symbol W Density (20°C)/gcm33 19.3
Atomic number 74 Melting point /°C -3380
No. of naturally occurring isotopes 5 Boiling point /°C -5500
Atomic weight 183.85(+/-0.03) ΔHfus/kJmol-1 -35
Electronic configuration [Xe]4f145d46s1 ΔHvap/kJmol-1 824(+/-21)
Metal radius(12-coordinate)/pm 139 ΔHf(monoatomic gas)/kJmol-1 849(+/-13)
Ionic radius(6-coordinate)/pm VI 60 Ionization energy/kJmol-1 I 770
Ionic radius(6-coordinate)/pm V 62 Ionization energy/kJmol-1 II 1700
Ionic radius(6-coordinate)/pm IV 66 Ionization energy/kJmol-1 III 2300
Electrical resistivity (20°C)/μohm cm ~5 Electronegativity χ 1.7
Evaporation Techniques
Temperature (oC) @Vap. Pressure Techniques Remarks
10-8 Torr 10-6 Torr 10-4 Torr Electron Beam Crucible Coil Boat
2117 2407 2757 Good - - - Forms volatile oxides. Films hard & adherent

Evaporation Materials
T9-5000-M pellets 6mm diameter x 3mm long
T9-5001-M pellets 6mm diameter x 6mm long
T9-5002-M pellets 12mm diameter x 6mm long
T9-5003-M pieces 1-3mm
T9-5011-M pellets 3mm diameter x 3mm long
T9-5012-M pieces 3-20mm

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

T9-3003-F 0.004" (0.1mm)
T9-3007-F 0.008" (0.2mm)
T9-10003-P -325 mesh
T9-10004-P 10 microns average
T9-10006-P <1 micron average
T9-4001-S 0.015" (0.38mm)
T9-4002-S 0.020" (0.5mm)
T9-4003-S 0.030" (0.76mm)
T9-4004-S 0.040" (1mm)
T9-4006-S 0.060" (1.5mm)
T9-4008-S 0.125" (3.175mm)
T9-4009-S 0.250" (6.35mm)
T9-4010-S 0.375" (9.525mm)
T9-4011-S 0.500" (12.7mm)
T9-4012-S 0.750" (19.05mm)
T9-4013-S 1" (25.4mm)
T9-1003-W 0.004" (0.1mm) annealed
T9-1009-W 0.010" (0.254mm)
T9-1012-W 0.020" (0.5mm)
T9-1014-W 0.040" (1.0mm) as drawn
T9-1014-W1 0.040" (1.0mm) annealed, stress-relieved