Magnetic levitation using high-temperature superconductors: a materials perspective

The relationships between system parameters and material properties for a superconducting levitation (or suspension) system are investigated. A superconducting levitation measurement system, constructed to produce 5-T uniform magnetic field and ~1-T/cm uniform gradient in static mode, was used to measure the levitation of high-temperature superconductors. Up to 0.5 T/cm of the gradient field may also be pulsed with switching time ~0.1 s which was designed to perturb freely levitated superconductors in dynamic measurements. The displacement of the levitated sample was monitored using phase-sensitive inductive techniques which provided the magnitude of a magnetic force. The control of temperature and magnetic field, as well as the data acquisition, was done through an IEEE-488 interface and a 9-μs analog-to-digital converter (ADC) using an 80386-based personal computer. The measurements and the theoretical analysis are compared