Resistivity of Tungsten (original) (raw)

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Bibliographic Entry Result(w/surrounding text) StandardizedResult
The University of the State of New York Reference Tables for Physical Setting/Physics. New York: The State Education Department, 2002. Resistivities at 20 °C Material Resistivity (Ω•m) Tungsten 5.60 × 10-8 5.60 × 10-8 Ωm
Lide, D. CRC Handbook of Chemistry and Physics, 75 edition. CRC Press, 1995: 12. "electrical resistivity of tungsten _R_W in n-ohm·m are given in _R_W = 48.0 (1 + 4.8297 × 10-3 T + 1.663 × 10-6 _T_2" n/a
Berkeley, U. Encyclopedia of Crystal Structures. MatSci, 1999. "the electrical resistivity is 7.5 ohm-cm, a relatively low value for an intermetallic solid" 7.5 × 10-7 Ωm
Zerda, T.W. Stefan Boltzmann Law. Texas Christian University. 2001. [see table 1] 5.65–115.0 × 10-8 Ωm
J. W. Davis (US) and S. Fabritsiev (RF). Pure Tungsten - Electrical Resistivity. ITER Material Properties Handbook. University of California, San Diego. [see table 2] 5.5–105 × 10-8 Ωm

Tungsten is a metallic element that has the highest melting point of any metal. Tungsten, symbol W on the periodic table, is one of the transition elements on the periodic table. The atomic number is 74. Tungsten resistivity is 52.8 Ωm at 20 °C, however as temperature increases, also does resistivity.

Table. 1. Resistivity of tungsten as a function of temperature

R/R300K Temp[K] ResistivityμΩ·cm R/R300K Temp[K] ResistivityμΩ·cm R/R300K Temp[K] ResistivityμΩ·cm R/R300K Temp[K] ResistivityμΩ·cm
1.0 300 5.65 5.48 1200 30.98 10.63 2100 60.06 16.29 3000 92.04
1.43 400 8.06 6.03 1300 34.08 11.24 2200 63.48 16.95 3100 95.76
1.87 500 10.56 6.58 1400 37.19 11.84 2300 66.91 17.62 3200 99.54
2.34 600 13.23 7.14 1500 40.36 12.46 2400 70.39 18.28 3300 103.3
2.85 700 16.09 7.71 1600 43.55 13.08 2500 73.91 18.97 3400 107.2
3.36 800 19.00 8.28 1700 46.78 13.72 2600 77.49 19.66 3500 111.1
3.88 900 21.94 8.86 1800 50.05 14.34 2700 81.04 20.35 3600 115.0
4.41 1000 24.93 9.44 1900 53.35 14.99 2800 84.70
4.95 1100 27.94 10.03 2000 56.67 15.63 2900 88.33

Table 2 Pure Tungsten - Resistivity

Temperature micro-ohms-cm
(°C) Ref. 1 Ref. 2
20 5.5
27 5.6
227 10
427 15
627 21
827 27
1000 33
1027 33
1227 40
1500 48
1527 51
2000 66
2500 84
3000 105

Pure tungsten is silver-white in color and is ductile; however it is more easily obtained in its impure state as steel-gray, which is hard and brittle. Tungsten melts at about 3410 °C (6170 °F), boils at about 5660 °C (10,220 °), and has a specific gravity of 19.5. The atomic weight of tungsten is 183.85 u.

Tungsten ranks 57th in abundance among the elements in the crust of the earth. It is never found free in nature, but occurs in combination with the other metals, notably in the minerals scheelite and wolframite, which are the important tungsten ores. To separate the element from its ore, the ore is first combined with sodium tungstate is then extracted with hot water and treated with hydrochloric acid to yield tungstate acid, H2WO4. The compound is then washed and dried to produced is treated in molds in an atmosphere of hydrogen and pressed into bars, which are hammered and rolled at high temperature to compact them and make them ductile.

Tungsten is mostly used in electrical appliances that give off heat and light because it is ductile and has a high resistivity. The principal uses of tungsten are as filaments in incandescent lamps, as wires in electric furnaces, and in the production of hard, tenacious alloys of steel. It is also used in the manufacture of spark plugs, electrical contact points, and cutting tools, and in X-ray tubes.

Deanna Stewart -- 2004