Relative Permittivity - the Dielectric Constant
Common materials and their relative permittivity.
The dielectric constant - also called the relative permittivity indicates how easily a material can become polarized by imposition of an electric field on an insulator. Relative permittivity is the ratio of "the permittivity of a substance to the permittivity of space or vacuum".
Relative permittivity can be expressed as
εr = ε / ε0 (1)
where
εr = relative permittivity - or dielectric constant
ε = permittivity of substance (C2/(N m2))
ε0 = permittivity of vacuum or free space (8.854187817 10-12 C2/(N m2))
Relative permittivity - εr - and permittivity - ε - for some substances. Note that permittivity may change with temperature for most materials.
Material | Relative Permittivity - εr - Load Calculator! 10-12 |
---|---|
Acetaldehyde (41° F) | 21.8 |
Acetic Acid (68° F) | 6.2 |
Acetic Acid (36° F) | 4.1 |
Acetone (77° F) | 20.7 |
Acetone (127° F) | 17.7 |
Acetone (32° F) | 1.0159 |
Acetyl Acetone (68° F) | 23.1 |
Acetyl Bromide (68° F) | 16.5 |
Acetyl Chloride (68° F) | 15.8 |
Acetyle Acetone (68° F) | 25.0 |
Acetylene (32° F) | 1.0217 |
Air (Dry) (68° F) | 1.000536 |
Air, Liquid (-191oC) | 1.4 |
Alcohol, Industrial | 16-31 |
Alumina | 9.3-11.5 |
Aluminum Bromide (212° F) | 3.4 |
Aluminum Fluoride | 2.2 |
Amber | 2.8-2.9 |
Ammonia (-74° F) | 25 |
Ammonia (-30° F) | 22.0 |
Ammonia (40° F) | 18.9 |
Ammonia (69° F) | 16.5 |
Aniline (32° F) | 7.8 |
Aniline (68° F) | 7.3 |
Aniline (212° F) | 5.5 |
Araldite | 3.6 |
Argon (68° F) | 1.000513 |
Bakelite | 3.5-5.0 |
Benzene (68° F) | 2.3 |
Body tissue | 8 |
Butane (30° F) | 1.4 |
Carbon dioxide (68° F) | 1.000921 |
Carbon disulfide | 2.6 |
Calcium | 3.0 |
Casting compound | 2.5 |
Caster oil | 4.7 |
Ceramic, MgNb2O6 | 21 |
Ceramic, ZnNb2O6 | 25 |
Ceramic, MgTa2O6 | 28 |
Ceramic, ZnTa2O6 | 38 |
Chlorine (32° F) | 2.0 |
Chloroform (68° F) | 4.8 |
Concrete | 4.5 |
Diamond | 5.5 - 10 |
Ebonite | 2.5 - 2.9 |
Epoxy Resin (Cast ) | 3.6 |
Ethanol (25oC, 77° F) | 24.3 |
Ethyl Acetate (77° F) | 6.0 |
Ethyl Alcohol (77° F) | 24.3 |
Ethylene glycol | 37 |
Formamide (20oC) | 84 |
Furfural | 42 |
R12 Dichlorodifluoromethane (70° F) | 2.4 |
Glass | 3.7 - 10 |
Glycerin, Liquid | 47-68 |
Glycerol (77° F) | 42.5 |
Granite | 7 - 9 |
Graphite | 10 - 15 |
Guttapercha | 4 |
Hard paper, laminated | 4.5 |
Hydrazine (20oC) | 52 |
Hydrocyanic acid (21oC) | 2.3 |
Hydrofluoric acid (0oC) | 83.6 |
Hydrogen peroxide (25oC) | 60 |
Ice (-2oC) | 3.2 |
Isoprene (77° F) | 2.1 |
Insulation of high voltage cables | 4.2 |
Insulation of telephone cables | 1.5 |
Marble | 8 |
Methanol (20oC)) | 33.6 |
Mica | 2.5 - 7 |
Mineral Oil (80° F) | 2.1 |
Mylar | 3.1 |
Neoprene | 6.7 |
Nitrogen (68° F) | 1.000580 |
Nylon | 4.0 - 5.0 |
Oil paper | 4 |
Olive oil | 3 |
Paper | 2.3 |
Paper, impregnated | 5 |
Paper, waxed | 2.5 |
Paraffin oil | 2.2 |
Paraffin Wax | 2.1-2.5 |
Petroleum | 2.2 |
Phenolic resin | 8 |
Plexiglass | 3.2 |
Polyester Resin | 2.8 - 4.5 |
Polyethylene, XLPE | 2.2-2.4 |
Polyamide | 2.8 |
Polymide | 3.4 |
Polypropylene | 2.2 |
Polystyrene | 3 |
Porcelain | 5.0-7.0 |
Pressed board | 4 |
Pyrex Glass | 4.3 - 5.0 |
Quartz | 4.5 |
Rubber | 3.0 |
Salt | 3.0 - 15.0 |
Sapphire | 8.9 - 11.1 |
Shellac | 3.5 |
Silica Sand | 2.5-3.5 |
Silicon | 11.0 - 12.0 |
Silicon dioxide | 3.9 |
Silicon oil | 2.2 - 2.8 |
Slate | 4 |
Sodium chloride | 5.6 |
Soft rubber | 2.5 |
Steatite | 6 |
Sulfur | 3.5 |
Sulfuric acid (20oC) | 84 |
Polytetrafluoroethylene (PTFE) | 2 |
Teflon, PTFE | 2.1 |
Titanium dioxide | 86 - 173 |
Transformer oil, mineral | 2.2 |
Transformer oil, vegetable | 2.5 |
Turpentine | 2.2 |
Vacuum | 1 |
Vulcanized fibres | 2.5 |
Water1) | 4 - 88 |
Wood, Dry | 2 - 6 |
1) Water - permittivity is 88 at 0 oC (32 oF) and drops with rising temperature. Permittivity is 80 at 20 oC (212 oF) and 55.3 at 100 oC (212 oF).