The effect of Pr6O11 doping on superconducting properties of MgB2

Abstract

AbstractIn this paper we report the effect of Pr6O11 doping on the structural and superconducting properties of MgB2. The bulk samples of Pr6O11‐doped MgB2 have been prepared with nominal compositions Mg1−x(Pr6O11)x/6B2 (where x = 0.0, 0.01, 0.02, 0.03, 0.04, and 0.05) via a standard solid‐state reaction route by sintering in a reducing atmosphere of Ar/H2. The superconducting transition temperature Tc of MgB2 is found to decrease from 39 to 37 K when x increases from 0 to 0.05. The XRD results show the presence of MgO and PrB6 secondary phases in the doped samples besides the main hexagonal phase of MgB2. Improvement in critical current density (Jc), irreversibility field (Hirr), and upper critical field (Hc2) of doped samples has been observed. The Jc values at 10 and 20 K of the x = 0.03 sample are higher in the entire field region (0–6 T). At 10 K and 2 T field the Jc values of undoped and 0.03 Pr6O11‐doped samples are 1.09 × 105 and 2.21 × 105 A/cm2, respectively. Variations of Hc2, Jc, Hirr, and flux‐pinning force (Fp) with doping concentrations have been studied in this paper and a correlation between these superconducting properties and structural characteristics of the samples has been found in the present work.