Preparation and properties of high Tc superconducting YBa2Cu3O7 and ferromagnetic oxide La0.67Ba0.33MnO3 multilayers

摘要

We have prepared superconducting YBa2Cu3O7 and ferromagnetic oxide La0.67Ba0.33MnO3 hetero-epitaxial multilayer samples by pulsed laser deposition. X-ray diffraction and ion channeling results indicate that epitaxial growth of ferromagnetic La0.67Ba0.33MnO3 films has been achieved on (100) LaAlO3 substrates. In situ epitaxial La0.67Ba0.33MnO3 thin films show giant negative magnetoresistance around 150 K and a magnetoresistance ratio, -(RH-R0)/R0, of more than 90%. A superconducting transition and the magnetoresistance effect were observed in YBa2Cu3O7/La0.67Ba0.33MnO3 multilayers simultaneously. The results suggest the possibility of an interface effect, which affects the resistivity and the superconductivity of the multilayers.