the correct proportions by atomic ratio of y 2 o 3 baco 3 and cuo were mixed and ground using a mortar and pestle the grinding operation was carried out until the entire mass exhibited a uniform dark grey color in the subsequent step this particular uniform color powder was placed in a ceramic crucible and put in a tube furnace at 950 u00b0 c for 16 hours under flowing o 2 after the furnace was shut off the powder was allowed to cool to room temperature inside the furnace under the flowing oxygen the resulting porous mass of yba 2 cu 3 o 7 x was ground once again and compacted to 1 2 inch diameter pellets and sintered at 900 degrees c for 5 and 1 2 hours under flowing oxygen once again the resultant was cooled to room temperature inside the furnace under flowing oxygen these sintered pellets of y 1 ba 2 cu 3 o 7 x exhibited a transition onset at 191 u00b0 c 82k in the next step the superconducting pellets were again ground and mixed with the required weights of al and ag 2 o to provide a mixture containing 55 of yba 2 cu 3 o 7 x by volume 40 of aluminum by volume and 5 ag 2 o by volume this mixture was again ground until it produced a uniform color then it was once again pressed into 1 2 inch diameter pellets having two millimeter thicknesses.