Their occurrence is partially explained by the Frohlich model, and Matthias noticed that none of them are lanthanides or actinides and related a high transition temperature in them to an odd number of valence electrons.  
Their occurrence is partially explained by the Frohlich model, and Matthias noticed that none of them are lanthanides or actinides and related a high transition temperature in them to an odd number of valence electrons.  Tuyn's law relates their threshold temperature to the critical strength of their external magnetic field, and a type one material's transition into one of these includes an exclusion of magnetic fields known as the Meissner effect.  In one prominent theory, their existence is explained by electrons condensing near the Fermi level into boson-like Cooper pairs. FTP name this class of materials described by the BCS theory, characterized by zero electrical resistance.
Their occurrence is partially explained by the Frohlich model, and Matthias noticed that none of them are lanthanides or actinides and related a high transition temperature in them to an odd number of valence electrons.  
superconductor