Superconducting Properties of Carbon and Zn Double-doped Mg1−x Zn x (B1−x C x )2

• DOI: 10.1007/s10948-010-0807-8
• Publication Date: 2010-07-01T03:22:16Z
• Authors: Hengwei Liu; Aimin Sun; Yanzhong Lu; Yaotong Ma; Jinyuan Ma; Guidan Wei; Long Zheng
• Keywords: Lattice constant; Transition temperature

A series of polycrystalline samples of Mg1−xZnx(B1−xCx)2 (x=0.00, 0.02, 0.04, 0.06, 0.08, and 0.10) were synthesized by a conventional solid-state reaction method under a background pressure about 10−3 Pa. Phase identification, crystal structure and superconducting transition temperature (Tc) were studied by means of X-ray diffraction (XRD) and resistivity measurements. The results indicated that the lattice parameters a and c show no clear trend in their changes with increasing doping level, and it turned out that the dopants had a marked effect on the crystal-lattice parameters and changed the crystal structure of the samples. The Tc for Mg1−xZnx(B1−xCx)2 decreased with C and Zn doping, but the rate of decrease was slower than single C-doped. We propose that the suppression of Tc by doping originates largely from the structural change.