CORRELATION OF FRICTIONAL LOSSES OF SPINNING LEVITATED MAGNETS WITH AC SUSCEPTIBILITY IN HIGH-TEMPERATURE SUPERCONDUCTORS

Measurements of both the ac magnetic susceptibility in melt processed and film Y-Ba-Cu-O and frictional losses of spinning permanent magnets levitated above Y-Ba-Cu-O are presented. A direct correlation is obse rved only when large susceptibility samples are studied indicative of the importance of grain boundary loss mechanisms. The increasing loss per revolution with increasing frequency for a spinning permanent magn et is explored. (C) 1996 American Institute of Physics.