Flux pinning behaviour of different types of Bi2212 single crystals

A study of the magnetic relaxation of a pure Bi2212 crystal, two lead-doped Bi2212 crystals and an iron doped Bi2212 crystal at various temperatures was carried out. The crystals in these measurements were fabricated by the self flux growth technique. The high quality of the samples with a high degree of preferred orientation of the crystallographic planes was observed from X-ray diffraction pattern (XRD) and electron back scattering pattern (EBSP) techniques. From XRD, the c-axis parameters of the pure single crystal, the lead doped single crystal and iron doped single crystal were found to be (30.7959 ±0.0733)Â, (30.6666 ±0.1037)Â and (30.8005 ± 0.0573)Â, respectively. The critical temperature Tc of the samples Bi2212, Bi(Pbl)2212, Bi(Pb2)2212 and Bi(Fe)2212 were found to be 88.5K, 67K, 82K and 72K, respectively.