We have directly measured the levitation force of levitated bulk supercondu
ctors. The levitation force had a hysteresis loop during increasing and dec
reasing field processes. Such a hysteretic behavior can be explained in ter
ms of hysteretic penetration of external field to the superconductor. Based
on such magnetization, we performed numerical simulations of the levitatio
n forces, which were fairly in good agreement with experimental data. (C) 2
001 Published by Elsevier Science B.V.