Thick film resistor fabricated with YBa2Cu3O 7-x superconducting powder

Thick-film resistor paste was prepared utilizing the characteristics of low resistivity and small positive temperature coefficient of resistivity (TCR) around the room temperature of the YBa ₂Cu₃O_7-x (YBCO) superconductor. PbO or PbO₂, together with Ag₂O, were added to densify the fired film and to achieve adequate resistivity values for practical applications. By adjusting the contents of Ag₂ O and PbO or PbO₂ in the YBCO, sheet resistivities ranging from a few ohms per square to several megaohms per square were obtained. Adding PbO₂ is superior to PbO, because using PbO ₂ makes material preparation easier, allowing for a smaller negative TCR (even though TCR values are still higher than expected). The relationships between the TCR of the fabricated resistors and individual TCRs of YBa₂Cu₃O_7-x, Ag₂O, and PbO were studied