We have succeeded in preparing a new single-phase of Pb2Sr2(Ho1-xCax)n-1Cun+1O2n+4 with n = 3 (Pb-3223 phase) and also a single phase of n = 2 (Pb-3212 phase) by thin film processing. The thin films, oriented along the c-axis, have been prepared on MgO(100) substrates by rf-sputtering at room temperature and post-annealing at 650 - 750°C in nitrogen. The Pb-3223 phase has been found to be stable at a lower temperature than the Pb-3212 phase and to become stable with increasing x. The thin films of the Pb-3212 phase show superconducting transition at 60 K, whereas those of the Pb-3223 phase do not show superconductivity above 4.2 K.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering