MICROSTRUCTURE AND PROPERTIES OF K2O DOPED SUPERCONDUCTING YBA2CU3O7-X

K doped YBa2Cu3Ox powders have been obtained by incorporating K2CO3 to previously coprecipitated amorphous hydroxide mixtures. Synthesis was performed at 900 degrees C and an orthorhombic 1 2 3 phase was the final product. Sintering of isopressed bars was carried out from 920 to 940 degrees C. K doping up to 5 at % led to the development of dense bodies with good superconducting behaviour. Oxygen pick-up during the cooling step following sintering was well accomplished despite the high density of the samples. Transition temperatures greater than or equal to 90K were measured, Doping above that percentage led to samples with lower density values. The presence of non-superconducting phases, such as CuO and a green phase, was very significant, and suppressed the superconducting transition.