Electrical transport properties of bulk MgB2 materials synthesized by   the electrolysis on fused mixtures of MgCl2, NaCl, KCl and MgB2O4
  Electrolysis was carried out on fused mixtures of MgCl2, NaCl, KCl and MgB2O4 under an Ar flow at 600C. Electrical resistivity measurements for the grown deposits show an onset of superconducting transition at 37 K in the absence of applied magnetic field. The resistivity decreases down to zero below 32 K. From an applied-field dependence of resistivity, an upper critical field and a coherence length were calculated to be 9.7 T and 5.9 nm at 0 K, respectively. 
Kenji Yoshii and Hideki Abe