I think you may mean below. Basically, low temperature superconductors (e.g. niobium titanium) are liquid helium cooled. High temperature superconductors (e.g

I think you may mean below. Basically, low temperature superconductors (e.g. niobium titanium) are liquid helium cooled. High temperature superconductors (e.g. YBCO, BSCCO) are everything else, but generally liquid nitrogen cooled.