High purity synthesis of YBa2Cu4O8 at low oxygen pressure

Two new simple procedures for the synthesis of the YBa2Cu4O8−δ compound are presented. The x‐ray diffraction (XRD) spectra show the presence of the 124 just after 20 h of high‐temperature treatment. The resistivity measurements show that the material produced is a superconductor. For one of the procedures the XRD analysis does not show the presence of impurities after 92 h of total treatment.