Development of YBCO levitators for simple applications

Levitation and suspension of a superconductor above and under a rare earth magnet is one of the promising applications of high temperature superconductors, e.g. in frictionless self-stabilized magnetic bearings. This paper describes a development of the seeded melt growth (SMC) method for Y-Ba-Cu-O (YBCO) levitators with regard to simplicity and to the limitation of the usually long preparation period. Attention was paid to a correct selection of the precursor powder as well as to the SMG process parameters and above all with respect to the resulting levitation force. Typical and highest levitation forces of about 16 N and 24 N, respectively, between the 21 mm diameter YBCO levitators and the neodymium-iron-boron permanent magnet at 77 K were obtained. In addition, a simple application of YBCO levitators, the superconducting magnetic top, is presented for demonstration.