Effects of the nano boron doping and permanent magnet on the magnetic levitation and stiffness performance of Sm1.75Ca(2.20−x)BxCu3.4Oy superconducting ceramics.

We have successfully fabricated a series of the SmCaBCuO bulk superconducting ceramics with different ratios of nanoscale Boron doping into mixture powder by the solid-state reaction method. Permanent magnets (PMs) with three different values in the same form were used for magnetic levitation force (MLF) measurements. During measurement of levitation forces between small PMs and bulk high Tc superconducting ceramic materials, significant hysteretic behavior was observed as a function of the distance between the magnet and the superconductor. We focused on the effect of doping and different permanent magnets on magnetic levitation force (MLF) measurements and magnetic stiffness calculations of materials, considering zero field-cooling (ZFC) and field-cooling (FC) conditions. It was seen that MLF decreased with the increase in boron dopant in the sample under ZFC conditions. We explained this result with weak bonds between grain boundaries, cracks and grain size reduction in the samples. Under FC conditions, with the increase of permanent magnet value and nano boron doping, the levitation force, which should be effective, left its place to the attractive force. Flux trapping centers formed by doping dominate the attractive force. The increase in doping caused a decrease in magnetic stiffness values. The increase in the permanent magnet caused an increase in the stiffness values of the material. This result agrees with the literature. The MLF and magnetic stiffness data got will be useful in the technological applications of maglev and carrier systems. [ABSTRACT FROM AUTHOR]