Thick film resistor fabricated with YBa/sub 2/Cu/sub 3/O/sub 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/sub 2/Cu/sub 3/O/sub 7-/x (YBCO) superconductor. PbO or PbO/sub 2/, together with Ag/sub 2/O, were added to densify the fired film and to achieve adequate resistivity values for practical applications. By adjusting the contents of Ag/sub 2/O and PbO or PbO/sub 2/ in the YBCO, sheet resistivities ranging from a few ohms per square to several megaohms per square were obtained. Adding PbO/sub 2/ is superior to PbO, because using PbO/sub 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 YBa/sub 2/Cu/sub 3/O/sub 7-/x, Ag/sub 2/O, and PbO were studied.<
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