Critical Current Density and n-values of MgB2 Strands over a Wide Range of Temperatures and Fields

Details Critical Current Density and n-values of MgB2 Strands over a Wide Range of Temperatures and Fields Critical Current Density and n-values of MgB2 Strands over a Wide Range of Temperatures and Fields

2011-08-29

arxiv.org/abs/1108.5775v2

Physics

Condensed Matter

Superconductivity

34 pages, 7 figures

Scientific paper

Transport measurements of critical current density, Jct, in monocore powder-in-tube MgB2 strands have been carried out at temperatures, T, of from 4.2 K to 40 K, and in transverse fields, B, of up to 14 T. Processing methods used were conventional continuous-tube-forming-filling (CTFF) and internal-magnesium-diffusion (IMD). Strands with several powder compositions were measured, including binary (undoped) MgB2, 2% carbon doped MgB2, and 3% carbon doped MgB2. Magnetization loops (M-B) were also measured, and magnetic critical current density, Jcm, values extracted from them. The transport, Jct(B) and magnetic, Jcm(B), critical current densities were compared. Also studied was the influence of doping on the resistively measured irreversibility field, Birr and upper critical field Bc2. Critical current densities, Jct, and n-values were extracted from transport measurements and were found to be universally related (for all B and T) according to n \propto Jctm in which m = 0.52 \pm 0.11. Likewise n was found to be related to B according to n \propto B-p with a T-dependent p in the range of about 0.08~0.21. Further analysis of the field (B) and temperature (T) dependencies of n-value resulted in an expression that enabled n(B,T), for all B and T, to be estimated for a given strand based on the results of transport Jct(B) measurements made at one arbitrarily chosen temperature.

Affiliated with

Also associated with

No associations

Rating

Critical Current Density and n-values of MgB2 Strands over a Wide Range of Temperatures and Fields does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Critical Current Density and n-values of MgB2 Strands over a Wide Range of Temperatures and Fields, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Critical Current Density and n-values of MgB2 Strands over a Wide Range of Temperatures and Fields will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-728642