Effect of sample size and magnetic flux distribution on the magnetic levitation force of Nd-Fe-B and Fe-B added sm123 superconductors

The aim of this study is to enhance the magnetic levitation force of Sm123 and (Sm123)0,75(Sm211)0,25 bulk samples by adding different amounts of Nd-Fe-B and Fe-B powders respectively. MPMG (Melt-Powder-Melt-Growth) method was used in this study. The structural properties of the samples were investigated by using differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscope (SEM), Energy dispersive X-ray analysis (EDX) and polarized optical microscope. The electrical properties were investigated by using PPMS (physical properties measurement system) by means of R-T and M-T measurements while the magnetic levitation force measurements were determined by using the magnetic levitation force measurements system. It was observed that, the magnetic levitation force values of Nd-Fe-B added samples decreased with increasing amount of magnetic impurity, while the magnetic levitation force values of Fe-B added samples first increased up to a saturation value after that decreased. To determine the effect of sample geometry on the magnetic levitation force, three Sm123 samples which have different radii were produced. When the magnetic levitation force values of produced samples under ZFC regime were compared, it was observed that magnetic levitation force increases with increasing of sample size. The effect of magnet size on the magnetic levitation force was also investigated. In this study, it was shown that the magnet size affects the magnetic levitation force as appropriate in literature.