Light carbon doping by oxygen-free paraffin wax to enhance the current density ofMgB2 in the entire field regime

Abstract

An oxygen-free hydrocarbon, paraffin wax, was evenly doped intoMgB2 by a new method to enhance the electromagnetic properties. A 5 wt% paraffinaddition resulted in significant enhancements of the upper critical field(Hc2), irreversible criticalfield (Hirr), and criticalcurrent density (Jc) properties in the entire field range at both 5 and 20 K. This excellent low-field and high-temperatureJc performance may be ascribed to the small carbon substitution, high critical temperature(Tc) and non-degraded grain coupling in the optimum paraffin-dopedMgB2 sample.