Crystallization behavior of MgB2 films fabricated on copper cathodes via electrochemical technique

An electrochemical technique was devised and settled to prepare MgB2 films on copper cathodes in MgCl2–Mg(BO2)2–NaCl–KCl molten salts. X-ray diffraction and scanning probe microscopy were adopted to investigate the phase composition and elements distribution of sample. R–T curve of film was monitored through standard four-probe method. Transmission electron microscope and scanning electron microscope analysis were chosen to investigate the crystallization behavior and morphology of the films at different electrolytic temperatures. The results indicated that MgB2 films were successfully fabricated on the copper cathodes, and the optimal electrolytic temperature was 601 °C. It was presumed that the non-conducting MgO impurities hindered continuous growth of MgB2 grain, which may result in dendritic growth of MgB2 grain.