REVERSIBLE MAGNETIC-PROPERTIES OF C-AXIS-ORIENTED SUPERCONDUCTING BI2SR2CA2CU3O10

Magnetization measurements on c-axis-oriented bulk superconducting Bi2Sr2Ca2Cu3O10 have been carried out with the magnetic field applied parallel to the c axis. Fitting the results to the variation model for magnetization suggested by Hao and Clem shows that the Ginzburg-Landau parameter-kappa is nearly constant for 74 less-than-or-equal-to T less-than-or-equal-to 86 K, with the value of 170 at 74 K, and slowly increases with temperature from approximately 86 to approximately 100 K. Kappa-diverges in the vicinity of T(c). This unusual temperature dependence of kappa(T) could come from extended fluctuation effects and a limitation of the Hao-Chem theory, which may fail to describe this extremely anisotropic Bi-based superconductor. By fitting the data with the value of kappa-equal to 170, the deduced values of some of the superconducting parameters are H(c)(0) = 10600 Oe, xi(0)ab = 10.5 +/- 0.6 angstrom, lambda(0)ab = 1940 +/- 13 angstrom, dH(c)2/dT congruent-to -3.68 T/K near T(c).