Conventional superconductors are materials that display superconductivity as described by BCS theory or its extensions.
Critical temperatures of some simple metals:
| Element | Tc (Kelvin) |
|---|---|
| Aluminum (Al) | 1.20 |
| Mercury (Hg) | 4.15 |
| Molybdenum (Mo) | 0.92 |
| Niobium (Nb) | 9.26 |
| Lead (Pb) | 7.19 |
| Tantalum (Ta) | 4.48 |
| Titanium (Ti) | 0.39 |
| Vanadium (V) | 5.30 |
| Zinc (Zn) | 0.88 |
Niobium and vanadium are type-II superconductors, while most other superconducting elements are type-I materials. Almost all compound and alloy superconductors are type-II materials.
The most commonly used conventional superconductor in applications is a niobium-titanium alloy - this is a type-II superconductor with a Tc of 11 K. The highest critical temperature so far achieved in a conventional superconductor was 39 K (-234 °C in magnesium diboride.
