Samples of (BiPb)2Sr2Ca2Cu3O 10+δ (BSCCO-2223) prepared by the sol-gel route were fluorinated in ClF3, resulting in approximately 3 fluorine atoms per formula as measured by fluoride selective-electrode. The samples were characterized by x-rays diffraction (XRD) and magnetization measurements. Neither the lattice parameters nor Tc (114K) changed after the fluorination. Nuclear magnetic resonance (NMR) measurements of 19F in the temperature range of 20-400K show that for T>270K there are 2 types of F nuclei environment. At T<270K only one line is resolved. At T<Tc, the fluorine linewidth increases with decreasing temperature. This is attributed to the formation of vortices. At very low temperatures, a new structure appears. This is attributed to an enhanced NQR signal from the Cu nuclei.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering