The study of superconducting and magnetic properties of bis oxalate (C22H22O6) added bulk MgB2

Abstract

The effect of bis oxalate (C22H22O6) addition on critical current density (Jc), lattice parameters, microstructure, superconducting temperature (Tc), magnetic levitation force (Fz) and lateral force (Fx) properties of bulk MgB2 has been studied for the first time in this study. Bulk MgB2 samples containing × wt% C22H22O6 (x ranging from 0, 1.5, 3, 4.5, 6 and 9 wt%) were fabricated with by in-situ solid state sintering technique at 775 °C. Fz and Fx measurements at 25 K and 30 K were made under zero-field-cooled (ZFC) and field- cooled (FC) regimes. The analysis of XRD and SEM points out a drop in lattice parameters and grain size of bis oxalate added samples and endorses C replacement in B sites in MgB2 lattice. It was observed that the bis oxalate addition has a progressive effect on magnetic levitation performance of MgB2. Whereas the maximum Fz and Fx values of undoped sample show 16.91 N and 7.10 N at 25 K, the maximum force values of the 3 wt% (BO) added sample correspond to 18.62 N and 8.49 N at 25 K. Furthermore, the (BO) addition meaningfully rises the critical current density (Jc) values of MgB2. The Jc values observed as 57 kA/cm2 and 70 kA/cm2 in self-field at 25 K for pure and 3 wt% (BO) doped MgB2 sample. The experimental results reveal that C22H22O6, as an example of carbohydrate, is an effective C-containing additive for the enhancement of the superconducting and magnetic levitation capacities of MgB2.