For various superconducting single crystals and polycrystals (including those of high-Tc compounds), the magnetization will be measured as a two-dimensional vector as the sample is rotated in a fixed magnetic field. These measurements seperate the diamagnetic shielding component of the magnetization, leaving the penetrating vortex-flux magnetization, whose frictional rotational behavior is related to vortex pinning forces that govern the critical current in these materials. The viscous response of the penetrating vortex-flux magnetization will also be investigated. For the single cystals, the measured anisotropy on the rotational magnetic properties will provide a full characterization of the unusual modes of vortex-flux behavior (including cross-flux effects) previously found in these studies. %%% The magnetic polarization of various superconducting materials (including those of high critical temperatures) will be measured as they are rotated in a magnetic field of different strengths. The frictional magnetic forces determined by these measurements are directly related to the maximum electic current that the materials can carry without losing their superconductivity. This information is needed to asses the technical potential for applications of these materials.
