For the development of levitation bearings and transport systems based on coated conductor (CC) tapes, it is important to know not only information about the levitation force during vertical displacement, but also data on the stability of the system under lateral displacements of a superconductor relative to permanent magnets, as well as the effect of temperature on lateral stability of the system. In our work, we present new experimental results on the effect of temperature on levitation and the restoring forces of CC-tape stacks subjected to cyclic lateral displacements relative to the position of the permanent magnet (PMG) .
For the measurements we used 12 mm wide commercially available CC-tape manufactured by SuperOx. The tape was cut into 12x12mm squares and stacked in stacks of 10, 30 and 50 elements. The measurements were carried out both in the zero-field cooling mode (ZFC) and in the field cooling mode (FC). The sample was cooled using a cryocooler at a vertical distance of 80 mm from the PMG in the case of ZFC mode and at a distance of 8.5 mm in the case of FC mode. Then, in both cases, the sample was moved to the final position at a distance of 7.5 mm from the PMG. After that, cyclic lateral movements of the superconductor over the permanent magnet were performed. Measurements of the vertical and lateral components of the force of interaction between the stack of CC-tapes and PMG were made. The measurements were carried out at various superconductor temperatures in the range 33 - 77.4 K. The experimental results allow us to conclude that both the levitation force and the lateral restoring force decrease with increasing temperature. A clear hysteresis of the vertical and horizontal components of the levitation force is noticeable. The hysteresis decreases with the number of elements in the stack, and increases with increasing temperature, up to 77.4 K for both the ZFC and FC modes. Numerical simulation of levitation force and restoring force by the finite element method has been carried out in the Comsol Multiphysics simulation environment. The calculation results are in a good agreement with the experimental data.

This work was supported by a grant from Russian Science Foundation (Project 17-19-01527).

Keywords: High temperature superconductors, Coated conductors, Levitation force, Guidance force