Using pulsed-laser deposition and N2O reactive gas, we have successfully fabricated very high quality c-axis n-type Ndi.ssCeo.isCuO4-y (NCCO) oxide superconducting thin films epitaxially grown on different substrates. The film shows a superconducting transition temperature Tc (R = 0 O) of 22.4K and a transition width of 0.2K from ac susceptibility measurement The critical current density Jc is 8x105 A/cm2 at 4.2K in zero magnetic field. The microwave surface resistance measured at 9.6 GHz shows a value of 3 mü at 4.2K in 500 nm-thick NCCO film, the best result reported so far for NCCO thin films. The oxygen deficiency is necessary to achieve the superconductivity in NCCO and the oxygen reduction during and after film deposition is critical. The oxidation and reduction processes are studied systematically for various substrate temperature, atmosphere and annealing duration.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering