[en] History of superconductivity has seen a series of sudden surprises. 1^st surprise is the discovery of superconductivity itself, by Prof. Heike Kamerlingh Onnes in Leiden, Holland, in 1911, with his clarification in 1913. Our journey will take us finally to the very surprising discovery (2008) and subsequent study of superconductivity in magnetic materials like BaFe₂ As₂ popularly known as iron superconductors. Many materials loose electrical resistance, R, completely, and expel all magnetic flux from inside on cooling it below what is called (superconducting) critical temperature (T_c) - under certain magnetic field, H, and current density, J. That infinitely conducting state is called the superconducting state, and the phenomenon is called Superconductivity. Using H > H_c or J > J_c will also destroy the superconducting state – with H_c and J_c being called (superconducting) critical field and (superconducting) critical current density, respectively. In fact, T_c is a function of H and J. A Type II superconductor allows, above H_c1 (the Lower Critical Field) and below H_c2 (the Upper Critical Field), magnetic flux to pass through the superconductor in form of flux tubes that are in normal state within the superconducting surrounding Applying a field H > H_c2, destroys the superconducting state. In general, H_c2 of Type II superconductors far exceed H_c of Type I superconductors. Type II has higher J_c too. Practical superconducting wires and tapes are, therefore, invariably made from Type II superconductors