电阻率与电导率
各种材料的电阻率和电导率

諸如金屬之類的導體具有高電導率和低電阻率。
玻璃等绝缘体具有低電導率和高電阻率。
半导体的電導率通常處於中等水平，但在不同條件下變化很大，例如材料暴露於電場或特定頻率的光，最重要是，也隨著半導體材料的温度和成分的變化。
半导体掺杂程度使電導率差異很大。某種程度上，摻雜更多會提高電導率。水、水溶液的電導率很大程度取決於其溶解盐的浓度以及在溶液中电离的其他化學物質。 水樣的電導率可用作樣品無鹽、無離子或無雜質程度的指標；水越純淨，電導率越低（電阻率越高）。 水中的電導率測量通常以比電導的形式報告。EC计通常用於測量溶液中的電導率。 粗略總結如下：
| 材料 | 电阻率， ρ (Ω·m) |
| --- | --- |
超导体: 0
金属: 10 -8
半导体: 多变的
电解质: 多变的
绝缘子: 10 16
超级绝缘体: 无穷大
此表显示了各种材料在20 °C（68 °F；293 K）的电阻率 ( ρ )、电导率和温度系数 。
| Material | Resistivity, ρ,   at 7002293150000000000♠20 °C (Ω·m) | Conductivity, σ,   at 7002293150000000000♠20 °C (S/m) | Temperature   coefficient (K−1) | Reference |
| --- | --- | --- | --- | --- |
| Silver | 6992159000000000000♠1.59×10−8 | 7007630000000000000♠6.30×107 | 6997380000000000000♠3.80×10−3 |  |
| Copper | 6992167999999999999♠1.68×10−8 | 7007596000000000000♠5.96×107 | 6997404000000000000♠4.04×10−3 |  |
| Annealed copper | 6992172000000000000♠1.72×10−8 | 7007580000000000000♠5.80×107 | 6997393000000000000♠3.93×10−3 |  |
| Gold | 6992244000000000000♠2.44×10−8 | 7007411000000000000♠4.11×107 | 6997340000000000000♠3.40×10−3 |  |
| Aluminium | 6992265000000000000♠2.65×10−8 | 7007377000000000000♠3.77×107 | 6997390000000000000♠3.90×10−3 |  |
| Brass (5% Zn) | 6992300000000000000♠3.00×10−8 | 7007334000000000000♠3.34×107 |  |  |
| Calcium | 6992335999999999999♠3.36×10−8 | 7007298000000000000♠2.98×107 | 6997409999999999999♠4.10×10−3 |  |
| Rhodium | 6992433000000000000♠4.33×10−8 | 7007231000000000000♠2.31×107 |  |  |
| Tungsten | 6992560000000000000♠5.60×10−8 | 7007179000000000000♠1.79×107 | 6997450000000000000♠4.50×10−3 |  |
| Zinc | 6992590000000000000♠5.90×10−8 | 7007169000000000000♠1.69×107 | 6997370000000000000♠3.70×10−3 |  |
| Brass (30% Zn) | 6992599000000000000♠5.99×10−8 | 7007167000000000000♠1.67×107 |  |  |
| Cobalt | 6992624000000000000♠6.24×10−8 | 7007160000000000000♠1.60×107 | 6997700000000000000♠7.00×10−3  [來源可靠？] |  |
| Nickel | 6992699000000000000♠6.99×10−8 | 7007143000000000000♠1.43×107 | 6997600000000000000♠6.00×10−3 |  |
| Ruthenium | 6992710000000000000♠7.10×10−8 | 7007141000000000000♠1.41×107 |  |  |
| Lithium | 6992928000000000000♠9.28×10−8 | 7007108000000000000♠1.08×107 | 6997600000000000000♠6.00×10−3 |  |
| Iron | 6992970000000000000♠9.70×10−8 | 7007103000000000000♠1.03×107 | 6997500000000000000♠5.00×10−3 |  |
| Platinum | 6993106000000000000♠10.6×10−8 | 7006943000000000000♠9.43×106 | 6997392000000000000♠3.92×10−3 |  |
| Tin | 6993109000000000000♠10.9×10−8 | 7006917000000000000♠9.17×106 | 6997450000000000000♠4.50×10−3 |  |
| Phosphor Bronze (0.2% P / 5% Sn) | 6993112000000000000♠11.2×10−8 | 7006894000000000000♠8.94×106 |  |  |
| Gallium | 6993140000000000000♠14.0×10−8 | 7006710000000000000♠7.10×106 | 6997400000000000000♠4.00×10−3 |  |
| Niobium | 6993140000000000000♠14.0×10−8 | 7006700000000000000♠7.00×106 |  |  |
| Carbon steel (1010) | 6993143000000000000♠14.3×10−8 | 7006699000000000000♠6.99×106 |  |  |
| Lead | 6993220000000000000♠22.0×10−8 | 7006455000000000000♠4.55×106 | 6997390000000000000♠3.90×10−3 |  |
| Galinstan | 6993289000000000000♠28.9×10−8 | 7006346000000000000♠3.46×106 |  |  |
| Titanium | 6993420000000000000♠42.0×10−8 | 7006238000000000000♠2.38×106 | 6997380000000000000♠3.80×10−3 |  |
| Grain oriented electrical steel | 6993460000000000000♠46.0×10−8 | 7006217000000000000♠2.17×106 |  |  |
| Manganin | 6993482000000000000♠48.2×10−8 | 7006206999999999999♠2.07×106 | 6994200000000000000♠0.002×10−3 |  |
| Constantan | 6993489999999999999♠49.0×10−8 | 7006204000000000000♠2.04×106 | 6994800000000000000♠0.008×10−3 |  |
| Stainless steel | 6993690000000000000♠69.0×10−8 | 7006145000000000000♠1.45×106 | 6996940000000000000♠0.94×10−3 |  |
| Mercury | 6993979999999999999♠98.0×10−8 | 7006102000000000000♠1.02×106 | 6996900000000000000♠0.90×10−3 |  |
| Bismuth | 6994129000000000000♠129×10−8 | 7005775000000000000♠7.75×105 |  |  |
| Manganese | 6994144000000000000♠144×10−8 | 7005694000000000000♠6.94×105 |  |  |
| Plutonium (0 °C) | 6994146000000000000♠146×10−8 | 7005685000000000000♠6.85×105 |  |  |
| Nichrome | 6994110000000000000♠110×10−8 | 7005670000000000000♠6.70×105  [來源請求] | 6996400000000000000♠0.40×10−3 |  |
| Carbon (graphite)  parallel to basal plane | 6994250000000000000♠250×10−8 to 6994500000000000000♠500×10−8 | 7005200000000000000♠2×105 to 7005300000000000000♠3×105  [來源請求] |  |  |
| Carbon (amorphous) | 6996500000000000000♠0.5×10−3 to 6996800000000000000♠0.8×10−3 | 7003125000000000000♠1.25×103 to 7003200000000000000♠2.00×103 | 3003500000000000000♠−0.50×10−3 |  |
| Carbon (graphite)  perpendicular to basal plane | 6997300000000000000♠3.0×10−3 | 7002330000000000000♠3.3×102 |  |  |
| GaAs | 6997100000000000000♠10−3 to 7008100000000000000♠108  [需要解释] | 6992100000000000000♠10−8 to 7003100000000000000♠103  [可疑] |  |  |
| Germanium | 6999459999999999999♠4.6×10−1 | 2.17 | 3001520000000000000♠−48.0×10−3 |  |
| Sea water | 6999210000000000000♠2.1×10−1 | 7000480000000000000♠4.8 |  |  |
| Swimming pool water | 6999330000000000000♠3.3×10−1 to 6999400000000000000♠4.0×10−1 | 6999250000000000000♠0.25 to 6999300000000000000♠0.30 |  |  |
| Drinking water | 7001200000000000000♠2×101 to 7003200000000000000♠2×103 | 6996500000000000000♠5×10−4 to 6998500000000000000♠5×10−2 |  | [來源請求] |
| Silicon | 7003230000000000000♠2.3×103 | 6996435000000000000♠4.35×10−4 | 3001250000000000000♠−75.0×10−3 |  |
| Wood (damp) | 7003100000000000000♠103 to 7004100000000000000♠104 | 6996100000000000000♠10−4 to 6997100000000000000♠10−3 |  |  |
| Deionized water | 7005180000000000000♠1.8×105 | 6995420000000000000♠4.2×10−5 |  |  |
| Ultrapure water | 7009182000000000000♠1.82×109 | 6990549000000000000♠5.49×10−10 |  |  |
| Glass | 7011100000000000000♠1011 to 7015100000000000000♠1015 | 6985100000000000000♠10−15 to 6989100000000000000♠10−11 |  |  |
| Carbon (diamond) | 7012100000000000000♠1012 | ~6987100000000000000♠10−13 |  |  |
| Hard rubber | 7013100000000000000♠1013 | 6986100000000000000♠10−14 |  |  |
| Air | 7009100000000000000♠109 to 7015100000000000000♠1015 | ~6985100000000000000♠10−15 to 6991100000000000000♠10−9 |  |  |
| Wood (oven dry) | 7014100000000000000♠1014 to 7016100000000000000♠1016 | 6984100000000000000♠10−16 to 6986100000000000000♠10−14 |  |  |
| Sulfur | 7015100000000000000♠1015 | 6984100000000000000♠10−16 |  |  |
| Fused quartz | 7017750000000000000♠7.5×1017 | 6982130000000000000♠1.3×10−18 |  |  |
| PET | 7021100000000000000♠1021 | 6979099999999999999♠10−21 |  |  |
| PTFE (teflon) | 7023100000000000000♠1023 to 7025100000000000000♠1025 | 6975100000000000000♠10−25 to 6977099999999999999♠10−23 |  |  |
有效溫度係數隨材料的溫度和純度等級而變化。 20°C 值在其他溫度下使用時，只是一個近似值。 例如，銅的溫度越高，係數就越低，且值0.00427 通常指定為7002273149999999999♠0 °C 。
银的极低电阻率（高导电率）是金属的特性。乔治·伽莫夫在他的科普书One, Two, Three...Infinity中简洁地总结了金属与电子相互作用的本质：
The metallic substances differ from all other materials by the fact that the outer shells of their atoms are bound rather loosely, and often let one of their electrons go free. Thus the interior of a metal is filled up with a large number of unattached electrons that travel aimlessly around like a crowd of displaced persons. When a metal wire is subjected to electric force applied on its opposite ends, these free electrons rush in the direction of the force, thus forming what we call an electric current.
廣泛認為木材是一種極好的絕緣體，但其電阻率敏感地取決於水分含量，潮濕的木材的絕緣性比烘乾的木材差至少7010100000000000000♠1010。足夠高的電壓（例如雷擊或某些高壓電線中的電壓）可能會導致絕緣擊穿和觸電風險，即使是明顯乾燥的木材也是如此。