Graphene micro-substrate-induced π gap expansion in MgB2

Authors

W. X. Li, University of WollongongFollow
Xun Xu, University of WollongongFollow
Q Chen, University of WollongongFollow
Yun Zhang, University of WollongongFollow
S H. Zhou, University of WollongongFollow
R Zeng, University of WollongongFollow
S. X. Dou, University of WollongongFollow

RIS ID

41465

Publication Details

Li, W., Xu, X., Chen, Q., Zhang, Y., Zhou, S. H., Zeng, R. & Dou, S. X. (2011). Graphene micro-substrate-induced π gap expansion in MgB2. Acta Materialia, 59 (19), 7268-7276.

Abstract

The lattice effect induced by tensile strain on the superconductivity of graphene–MgB₂ composites was studied systematically to deduce the electron–phonon coupling (EPC) and the multiple superconducting gap behavior. Compared with nano-carbon doped MgB₂, graphene–MgB₂ composites show larger lattice parameters and higher critical superconducting transition temperatures (T_c). The EPC strength of MgB₂ with ∼2 wt.% graphene addition is even higher than that of the pure reference sample, as estimated from the Sommerfeld constant. The π gap was found to be expanded by graphene addition through the analysis of heat capacity data, and it is responsible for both the enhanced EPC strength and the weak dependence of T_c on the graphene content.

Grant Number

ARC/DP0770205

Additional Grant Number

http://purl.org/au-research/grants/ARC/DP0770205