Two EPR lines, one having an axially symmetric g tensor and the other an isotropic g tensor, are observed in mixed n = 2/n = 3 phase samples of the Bi1.5Pb0.5Sr2Can-1CunO2n+4 superconductor. No EPR spectra are, however, observed in phase pure (as determined by X-ray diffraction) n = 2 and n = 3 samples prepared under similar conditions. The EPR line intensities decrease as the temperature is lowered through Tc approximately following the decrease in resistance to zero of the samples. The spectra are attributed to point defects localized on copper-oxygen complexes at dislocations between n = 2 and n = 3 phase intergrowths, which have been identified in microcrystals of these samples by high resolution lattice imaging.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering