摘要 |
PURPOSE:To vary and control a potential according to an input voltage by providing a superconducting material having a temperature range between Tc ON set (temperature at which superconduction starts) of a thin film and its Tco (temperature at which electric resistance becomes zero in principle) on an insulating substrate having non-superconductivity, and composing a pair of output electrodes through which a current flows from one to the other. CONSTITUTION:A thin superconducting film 2 made of thin superconducting films 3, 4, 5 on a substrate 1 having non-superconductivity, a pair of output electrodes 8, 9, a control electrode 10, and a thin film 11 under the electrode 10 are provided. The substrate uses yttria-stabilized zirconium, and a superconducting material having (A1-xBx)yCuOz, wherein x=0.01-0.3, y=1.3-2.2, z=2-4, and where A is selected from Y, Ga, Zr, Ge and Yb, and B is selected from Ba, Sr, Ca, Mg and Be is used thereon. Simultaneously upon formation or after the formation, it is thermally annealed at 600-900 deg.C for 5-10 hours, patterned, and an insulating film 11 is further formed by a vapor growth method. Then, the electrodes 10 and 8, 9 are formed of copper, or a copper and nickel compound. 10% and 90% between the Tc ON set and Tco are defined as Tc10 and Tc90. |