Field and Temperature Dependence of Susceptibility of Single Crystal Bi_(2)Sr_(2)CaCu_(2)O_(8)

Susceptibility measurements on Bi_(2)Sr_(2)CaCu_(2)O_(8) single crystals do reveal field-induced-suppression of sharp phase transition.No apparent anisotropy of the susceptibility was observed when magnetic field was applied along the three main directions a,b and c.The three dimensional isotropic fluctuation diamagnetism theory is proposed to explain our experimental finding of isotropic susceptibility.In a wide range of magnetic field,the temperature dependence of susceptibility does not show any obvious change in its character when the sample enters into expected vortex-lattice state from vortex-liquid state.