AC susceptibility characterisation of Bi-Sr-Ca-Cu-O (2212) single crystals: annealing effects
Abstract Single crystals of Bi 2 Sr 2 CaCu 2 O x have been grown by directional solidification method in order to analyze annealing effects on critical superconducting temperature ( T c ) by AC susceptibility measurements. Structural modifications were studied by X-ray diffraction. A decrease of the transition width was observed in samples treated in oxygen or argon atmospheres at 500 °C for 10 h. Higher T c values were obtained for argon annealings. The magnitude of T c changes and its correlation with c lattice parameter is found to be sample-dependent.