Pinning improvement of A15 applied superconducting materials

Electron-phonon coupling is one of the most common interaction in superconducting materials ranging from Nb-3 Sn, MgB2, iron-based superconductors and high temperature cuprates such as YBa2Cu3O7-delta and HgBa2Ca2Cu3O8+delta. However an importance of the electron-phonon coupling constant, lambda(ep), should not be underestimated for characterisation of the electronic properties of superconducting materials, but it is important that the enhanced flux pinning mechanism can be hold responsible for the applicability of the A15 superconducting materials in emerging hydrogen cryomagnetic technology where temperature of the liquid H-2 can be as low as 14 K.