Comparison of Type – I and Type – II Superconductors

Based on the behavior and properties of Superconductors, these are classified into two categories-
(1) Type – I Superconductors: Low Temperature Superconductors.
(2) Type – II Superconductors: High Temperature Superconductors.

Type – I and Type – II superconductors slightly different in their behavior and properties. The comparison of type-I and type – II superconductors is shown in the table below

Type – I SuperconductorsType – II Superconductors
Low critical temperature (typically in the range of 0K to 10K)High critical temperature (typically greater than 10K)
Low Critical magnetic field (Typically in the range of 0.0000049 T to 1T)High Critical magnetic field (Typically greater than 1T)
Perfectly obey the Meissner effect: Magnetic field cannot penetrate inside the material.Partly obey the Meissner effect but not completely: Magnetic field can penetrate inside the material.
Exhibits single critical magnetic field.Exhibits two critical magnetic field
Easily lose the superconducting state by low-intensity magnetic field. Therefore, type-I superconductors are also known as soft superconductors.Does not easily lose the superconducting state by external magnetic field. Therefore, type-II superconductors are also known as hard superconductors.
The transition from a superconducting state to a normal state due to the external magnetic field is sharp and abrupt for type-I superconductors.The transition from a superconducting state to a normal state due to the external magnetic field is gradually but not shape and abrupt. At lower critical magnetic field (HC1), type-II superconductor starts losing its superconductivity. At upper critical magnetic field (HC2), type-II superconductor completely loses its superconductivity. The state between lower critical magnetic field and upper magnetic field is known as an intermediate state or mixed state.
Due to the low critical magnetic field, type-I superconductors cannot be used for manufacturing electromagnets used for producing strong magnetic field.Due to the high critical magnetic field, type-II superconductors can be used for manufacturing electromagnets used for producing strong magnetic field.
Type-I superconductors are generally pure metals.Type-II superconductors are generally alloys and complex oxides of ceramics.
BCS theory can be used to explain the superconductivity of type-I superconductors.BCS theory cannot be used to explain the superconductivity of type-II superconductors.
These are completely diamagnetic.These are not completely diamagnetic
These are also called as Soft Superconductors.These are also called as Hard Superconductors.
These are also called as Low-temperature Superconductors.These are also called as High-temperature Superconductors.
No mixed state exists in type-I Superconductors.A mixed state exists in type-II Superconductors.
Slight impurity does not affect the superconductivity of type-I superconductors.Slight impurity greatly affects the superconductivity of type-II superconductors.
Due to the low critical magnetic field, type-I superconductors have limited technical applications.Due to the high critical magnetic field, type-II superconductors have wider technical applications.
Examples: Hg, Pb, Zn,etc.Examples: NbTi, Nb3Sn, etc.

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