Influence of the carbon substitution on the critical current density and AC losses in MgB2 single crystals

Abstract

The DC magnetization and AC complex magnetic susceptibilities were measured for MgB2 single crystals, unsubstituted and carbon substituted with the composition of Mg(B_0.94C_0.06)2. The measurements were performed in AC and DC magnetic fields oriented parallel to the c-axis of the crystals. From the DC magnetization loops and the AC susceptibility measurements, critical current densities (Jc) were derived as a function of temperature and the DC and AC magnetic fields. Results show that the substitution with carbon decreases Jc at low magnetic fields, opposite to the well known effect of an increase of Jc at higher fields. AC magnetic losses were derived from the AC susceptibility data as a function of amplitude and the DC bias magnetic field. The AC losses were determined for temperatures of 0.6 and 0.7 of the transition temperature Tc, so close to the boiling points of LH2 and LNe, potential cooling media for magnesium diboride based composites. The results are analyzed and discussed in the context of the critical state model.

arXiv comment10 pages, 7 figures, 1 table

References in corpus (11)

• Systematic effects of carbon doping on the superconducting properties of Mg(B${}_{1-x}$C${}_x$)${}_2$
• Enhancement of the high-field critical current density of superconducting MgB2 by proton irradiation
• Carbon substitution in MgB2 single crystals: structural and superconducting properties
• Carbon-substituted MgB2 single crystals
• Intralayer Carbon Substitution in the MgB2 Superconductor
• Effect of carbon nanotube doping on critical current density of MgB2 superconductor
• Carbon-substitution effect on the electronic properties of MgB${}_2$ single crystals
• Mixed state properties of superconducting MgB2 single crystals
• Substitution induced pinning in MgB_2 superconductor doped with SiC nano-particles
• Al substitution in MgB2 crystals: influence on superconducting and structural properties
• Peak effect in single crystal MgB${}_2$ superconductor for $\mathbf{H}\parallel c$-axis

Cited by in corpus (1)

• High-pressure high-temperature solution growth, structural, and superconducting properties of Fe-substituted MgB2 single crystals