Effects of High Pressure Using Cold Isostatic Press on the Physical Properties of Nano-SiC-Doped MgB2

Abstract

In this paper, we are presenting the effects of pressure using cold isostatic press (CIP) on the physical properties of nano-SiC-doped bulk sample Mg1.15B1.96C0.04. Effects on lattice parameters, critical current density (J c), upper critical field (B c2), irreversibility field (B irr), grain connectivity, anisotropy, and flux pinning force maximum as a function of the pressure have been thoroughly investigated. X-ray diffraction (XRD) analysis shows that a and c lattice parameters are decreased due to the CIP. The mass density of the pressed samples is increased. There is no change in the T c of the pressed samples as compared to that of the unpressed one. The J c shows enhancement in high-field region due to the application of CIP. Surprisingly, our CIP-applied samples show lower J c at low fields below 3 T. The J c of the sample pressed at 0.4 GPa shows enhancement by a factor of 4 than that of the unpressed one at 6 T and 20 K while depressing by a factor of 1.1 at 2 T, and the sample pressed at 0.6 GPa has suppressed J c throughout the entire field range measured. Such behavior is indicative of increased anisotropy as a result of CIP. This suggests that an optimum CIP value exists that improves J c in both field ranges. The anisotropy of the CIP-applied samples is increased with the exception of 0.4 GPa. There is also noticeable enhancement in the B c2 and B irr in all the pressed samples.