SERQUIS Adriana Cristina
Correlated enhancement of Hc2 and Jc in carbon nanotube doped MgB2
A. SERQUIS; G. SERRANO; S. M. MORENO; L. CIVALE; B. MAIOROV; F. BALAKIREV; M. JAIME
SUPERCONDUCTOR SCIENCE AND TECHNOLOGY
IOP PUBLISHING LTD
Año: 2007 vol. 20 p. 12 - 12
The use of MgB2 in superconducting applications still awaits thedevelopment of a MgB2-based material where current-carrying performanceand critical magnetic field are optimized simultaneously. We achieved this bydoping MgB2 with double-wall carbon nanotubes (DWCNT) as a source ofcarbon in polycrystalline samples. The optimum nominal DWCNT contentfor increasing the critical current density, Jc, is in the range 2.510 at.%depending on field and temperature. Record values of the upper critical field,Hc2(4 K) = 41.9 T (with extrapolated Hc2(0) ≈ 44.4 T), are reached in abulk sample with 10 at.% DWCNT content. The measured Hc2 versus Tdependences for all samples are successfully described using a theoreticalmodel for a two-gap superconductor in the dirty limit first proposed byGurevich and co-workers.