Superconductor classification

By their magnetic properties

• Type I superconductors: those having just one critical field, H_c, and changing abruptly from one state to the other when it is reached.
• Type II superconductors: having two critical fields, H_c1 and H_c2, being a perfect superconductor under the lower critical field and leaving completely the superconducting state to a normal conducting state above the upper critical field, being in a mixed state when between the critical fields.

• By the understanding we have about them

• Conventional superconductors: those that can be fully explained with the BCS theory or related theories.
• Unconventional superconductors: those that failed to be explained using such theories, e.g.:
• *Heavy fermion superconductors

By their critical temperature

• Low-temperature superconductors, or LTS: those whose critical temperature is below 30 K.
• High-temperature superconductors, or HTS: those whose critical temperature is above 30 K.

By material constituents and structure

• Some pure elements, such as lead or mercury.
• * Some allotropes of carbon, such as fullerenes, nanotubes, or diamond.
• Alloys, such as
• * Niobium-titanium, whose superconducting properties were discovered in 1962.
• Ceramics, which include
• * Cuprates i.e. copper oxides
• ** The YBCO family, which are several yttrium-barium-copper oxides, especially YBa₂Cu₃O₇. They are the most famous high-temperature superconductors.
• * Iron-based superconductors, including the oxypnictides
• * Magnesium diboride, whose critical temperature is 39K, being the conventional superconductor with the highest known temperature.
• * non-cuprate oxides such as BKBO
• other