Burned Rice Husk: An Effective Additive for Enhancing the Electromagnetic Properties of MgB₂ Superconductor

Abstract

We investigated the effect of doping of burned rice husk which contains ultrafine SiO2 and highly reactive carbon, on the crystal lattice and superconducting properties of MgB2 superconductor prepared by an in situ powder in sealed tube method. XRD, TEM, and magnetic measurements confirm the substitution of carbon atoms at boron sites in the MgB2 lattice and the formation of intragrain nanoinclusions in MgB2. From JC (H) characteristics, doped samples show a drastic enhancement of JC compared with pure MgB2. The enhancement of in‐field JC values is due to the flux pinning on lattice defects produced by C substitution and nanoscale inclusions of impurity phases.

Rare earth (RE – Ce, Gd) modified Nd1−xRExFeAsO0.7F0.3 superconductor with enhanced magneto-transport properties

“…34 In the present case, both Ce and Gd substitution at Nd site create lattice defects which help in pinning the ux lines on the defects thereby enhancing the current density at applied elds but at higher elds NdCe1 outdo NdGd15. The doped samples show competitively better J C (H) performance in comparison to the pristine sample Nd3.…”

Transport properties of sealed MgB2/Fe/Ni multifilamentary wires heat treated in air

“…MgB 2 has the potential to compete and even to excel the performance of NbTi/Nb 3 Sn for practical applications if the upper critical field (H C2 ), the irreversibility feld (H irr ) and the in-field critical current density [J C (H)] are improved [3,4]. Carbon doping by various additives like nano carbon, carbon nano tubes, nano metal carbides, carbohydrates, SiC and burned rice husk are found to be very promising for enhancing the field performance of MgB 2 conductors [5][6][7][8][9].…”

Doping effect of nano-Ho2O3 and naphthalene in MgB2 superconductor prepared by powder-in-sealed-tube method

“…With these methods, point defects in MgB 2 superconductor were created in the nano-meter scale, which acts as flux pinning centres. [6][7][8][9][10][11] Chemical doping has been found to be one of the suitable and most effective method to improve the superconducting properties of MgB 2 . Depending on the nature of doping materials, dopants react with Mg/B to produce secondary phase or they substitute at Mg/B site or they remain in superconducting matrix without undergoing any chemical reaction.…”