Anomalous Reversible Torque in Layered Superconducting Bi$\text{}_{2}$Sr$\text{}_{2}$CaCu$\text{}_{2}$O$\text{}_{x}$ Single Crystal

Magnetic anisotropy of layered superconducting Bi$\text{}_{2}$Sr$\text{}_{2}$CaCu$\text{}_{2}$O$\text{}_{x}$ single crystal was investigated by the torque method in the reversible regime. The torque was analyzed in the model taking into account 2D layered structure. Considered model gives the better fit to the data when the magnetic field is applied near (a, b) plane. Obtained results establish to 6×10$\text{}_{3}$ value of the superconducting effective mass anisotropy coefficient ε.