Physics – Condensed Matter – Superconductivity
Scientific paper
2006-08-31
J. Nanosci. Nanotechnol. 7, No. 6, 1804--1809 (2007)
Physics
Condensed Matter
Superconductivity
8 pages, 6 figures. To be published in J. Nanoscience and Nanotechnology
Scientific paper
10.1166/jnn.2007.720
In the present study, we report a systematic study of doping/ admixing of carbon nanotubes (CNTs) in different concentrations in MgB2. The composite material corresponding to MgB2+ x at.%CNTs (35 at.% > x > 0 at.%) have been prepared by solid-state reaction at ambient pressure. All the samples in the present investigation have been subjected to structural/ microstructural characterization employing XRD, SEM and TEM techniques. The magnetization measurements were performed by PPMS and Tc & Jct measurements have been done by the four-probe technique. The microstructural investigations reveal the formation of MgB2-CNTs composites. A CNT connecting the MgB2 grains may enhance critical current density due to its size (~ 5-20 nm diameter) compatible with coherence length of MgB2 (~ 5-6 nm) and ballistic transport current carrying capability along the tube axis. The Jct of MgB2 samples with varying CNTs concentration have been found to vary significantly e.g. Jct of the MgB2 sample with 10 at.% CNT addition is ~2.3 x 10^3 A/cm2 and its value for MgB2 sample without CNT addition is ~7.2x10^2 A/cm2 at 20K. The optimum result on Jc is obtained for 10 at.% CNTs admixed MgB2 sample at 5K, the Jc reaches ~5.2 x10^6 A/cm2 in self field, ~1.6 x 10^6 A/cm2 at 1T, ~2.9 x 10^5 A/cm2 at 2.6T and \~3.9 x 10^4 A/cm2 at 4T. The high value of intragrain Jc in 10 at.% CNTs admixed MgB2 superconductor has been attributed to the incorporation of CNTs into the crystal matrix of MgB2, which are capable of providing effective flux pinning centres. A feasible correlation between microstructural features and superconducting properties has been put forward.
Giri Rajiv
Malik* S. K.
Shekhar Chandra
Srivastava O. N.
No associations
LandOfFree
Improved Critical Current Density of MgB2 Carbon Nanotubes (CNTs) Composite 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 Improved Critical Current Density of MgB2 Carbon Nanotubes (CNTs) Composite, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Improved Critical Current Density of MgB2 Carbon Nanotubes (CNTs) Composite will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-396586