superconductor,type 1 and type 2

What is a superconductor?

• when the temperature of the material is decreased below the critical temperature then the material show zero resistance it means there is no loss of electricity flowing through it.

• Superconductors are materials that conduct electricity with no resistance. This means that, unlike the more familiar conductors such as copper or steel, a superconductor can carry a current indefinitely without losing any energy. 

• They also have several other very important properties, such as the fact that no magnetic field can exist within a superconductor.

type-Ⅰ and type- Ⅱ superconductor-

Type I superconductors are those superconductors which lose their superconductivity very easily or abruptly when placed in the external magnetic field.

• After Hc, the Type I superconductor will become a conductor.

• Type I superconductors are also known as soft superconductors because of this reason that is they loose their superconductivity easily.

• Type I superconductors perfectly obey the Meissner effect.

• Example of Type I superconductors: Aluminum (Hc = 0.0105 Tesla), Zinc (Hc = 0.0054)

• Type II superconductors are those superconductors which loose their superconductivity gradually but not easily or abruptly when placed in the external magnetic field.

• The state between the lower critical magnetic field (Bc1) and upper critical magnetic field (Bc2) is known as vortex state or intermediate state.

• After Bc2, the Type II superconductor will become a conductor.

• Type II superconductors are also known as hard superconductors because of this reason that is they lose their superconductivity gradually but not easily.

• Type II superconductors obey the Meissner effect but not completely.

• Example of Type II superconductors: NbN (Bc = 8 x 106 Tesla), Babi3 (Bc = 59 x 103Tesla)

• Application of Type II superconductors: Type II superconductors are used for strong field superconducting magnets.

Meissner effect

When a material makes the transition from the normal to the superconducting state, it actively excludes magnetic fields from its interior; this is called the Meissner effect.

           The expulsion of a magnetic field from the interior of a material that is in the process of becoming a superconductor, that is, losing its resistance to the flow of electrical currents when cooled below a certain temperature, called the transition temperature, usually close to absolute zero. The Meissner effect, a property of all superconductors.