Abstract
The effect of bis oxalate (C22H22O6) addition on critical current density (J(c)), lattice parameters, microstructure, superconducting temperature (T-c), magnetic levitation force (F-z) and lateral force (F-x) properties of bulk MgB2 has been studied for the first time in this study. Bulk MgB2 samples containing x 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 degrees C. F-z and F-x 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 F-z and F-x 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 (J(c)) values of MgB2. The Jc values observed as 57 kA/cm(2) and 70 kA/cm(2) 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.
NSTL
Elsevier