Question: what are type 1 and type 2 superconductors?
Answer: A type I superconductor keeps out the whole magnetic field until a critical app- lied field Hc reached. ... A type II superconductor will only keep the whole magnetic field out until a first critical field Hc1 is reached. Then vortices start to appear. A vortex is a magnetic flux quantum that penetrates the superconductor.