In type-I superconductors, superconductivity is abruptly destroyed via a first order phase transition when the strength of the applied field rises above a critical value Hc. This type of superconductivity is normally exhibited by pure metals, e.g. aluminium, lead, and mercury.
Type-I superconductors are characterized by a first-order phase transition where superconductivity disappears upon exceeding a critical field strength (Hc). This phenomenon is typically observed in pure metals such as aluminum, lead, and mercury.