Conductive polymer/high-Tc supercondcutor brayer structures and devices

Summary form only given. The fabrication of electronic devices from conductive polymer materials has attracted much attention recently. Schottky diodes, molecular transistors, metal-insulator-semiconductor diodes, MIS field effect transistors and light emitting diodes have all been prepared utilizing such substances. With the discovery of high temperature superconductivity, new opportunities now exist for the study of molecule/superconductor interactions. The preparation of a hybrid conducting polymer/high-temperature superconductor device consisting of a polypyrrole coated YBa/sub 2/Cu/sub 3/O/sub 7/-/spl part/ microbfidge is reported. Electrochemical techniques are exploited to alter the oxidation state of the polymer and, in doing so, it is found for the first time that superconductivity can be modulated in a controllable and reproducible fashion by a polymer layer. Whereas the neutral (insulating) polypyrrole only slightly influences the electrical properties of the underlying YBa/sub 2/Cu/sub 3/O/sub 7/-/spl part/ film, the oxidized (conductive) polymer depresses Tc by more than 50K. In a similar fashion, the oxidation state of the polymer is found to reversibly modulate the magnitude of J/sub c/, the superconducting critical current. Thus, a new type of molecular switch for controlling superconductivity is demonstrated. Moreover, contact resitance measurements conducted as a function of temperature have been completed in an effort to explore polymer/superconductor charge transfer effects both above and below Tc.