Torque magnetometry: A new probe of dimensionality in high-T_c superconductors

Abstract

A single crystal of a high-T _c superconductor experiences a torque when it is placed in a magnetic field. This phenomenon has provided a useful experimental probe for investigating the superconducting anisotropy of high-T _c materials. It is pointed out here that it also offers a probe of their superconducting dimensionality. Some new torque magnetometry data for single-crystal Tl₁Ba₂CaCu₂O_x are discussed. The data reported are consistent with the view that this material is intrinsically two dimensional in character.