https://doi.org/10.1351/goldbook.S06137
A transition at the @[email protected], \(T_{\text{c}}\), below which the @[email protected] of electrical conductors becomes zero and @[email protected] is excluded. Examples: The transitions of Nb3Sn, Nb3Al and V3Si to superconductors (\(15\ \text{K} < T_{\text{c}} < 20\ \text{K}\)) and YBa2Cu3O7-x (\(x\approx 0.2\)) at \(90\ \text{K}\).