SiC and carbon nanotube distinctive effects on the superconducting properties of bulk MgB2

• DOI: 10.1063/1.2832463
• Publication Date: 2008-01-22T23:39:06Z
• Authors: G. Serrano; A. Serquis; S. X. Dou; S. Soltanian; L. Civale; B. Maiorov; T. G. Holesinger; F. Balakirev; M. Jaime
• Keywords: Critical field

This work describes in detail the simultaneous enhancement of upper critical field (Hc2) and current density (Jc) MgB2 bulk samples doped with nano-SiC particles, as well single-walled double-walled (dw) carbon nanotubes (CNTs). The magnetization properties were examined a superconducting quantum interference device magnetometer, four-probe transport measurements performed using 50T pulsed magnet to determine Hc2(T). We found that Jc is similar all at 5K but addition more effective improve flux pinning high temperature range (T⩾20K); this improvement cannot solely be attributed C incorporation lattice also presence other types defects (i.e., several kinds nanoinclusions). CNTs produce better enhance Hc2 [i.e., dwCNT-doped reached record Hc2(0)∼44T value for MgB2]. All Hc2(T) curves obtained different doping can successfully described model two-gap superconductor dirty limit.