Bi系酸化物超伝導体の高温電気抵抗と超伝導特性に及ぼす熱処理の影響

概要

論文の詳細を見る
Two peaks in the resistivity of the Bi2Sr2CaCu2Oy were detected at 300 and 650°C on heating process, but no peak was detected at 300°C on cooling process in spite of holding at 300°C for 100hr. In order to elucidate the cause of the peak at 300°C, the measurments of high temperature resistivity, Tc, thermogravimetry and X-ray diffraction were carried out for the Bi2Sr2CaCu2Oy quenched for various temperatures. Tc and normal-state resistivity as a function of a quenching temperature, Tq, had a steep minimum at Tq=300°C. The high temperature resistivity was also strongly dependent on Tq, but had a peak or a slope change at about 300°C on heating. X-ray diffraction showed that no change was found before and after quenching or high temperature resistivity measurement up to 400°C. The weight decrease was detected at 350°C during heating in air, but little change during cooling process. From these results, it may be considered that the peak in the resistivi-ty at 300°C is due to the decrease in the electrical hole concentration compensating the increase in the oxygen vacancy concentration. Further detailed research is in progress.
社団法人粉体粉末冶金協会の論文