The effect of Mg and C contents on TC in MgCN3, and structure and superconductivity of MgCNi3-x Co x were studied. It is found that the excess of Mg and C in initial material mixture is favorable to improvement inT c ...The effect of Mg and C contents on TC in MgCN3, and structure and superconductivity of MgCNi3-x Co x were studied. It is found that the excess of Mg and C in initial material mixture is favorable to improvement inT c and helps to obtain single-phase samples. For preparing MgCNi3 superconductor, the optimum composition of starting materials is MgC1.45Ni3 with excess of Mg (20 wt.%) of the stoichiometric composition. In gCNi3-x Co x system, a continuous solid solution is formed, lattice parameter decreases slightly andT c decreases obviously with increasingx. A suppression of superconductivity is observed due to the substitution of Co (Mn) for Ni. The suppression effect is smaller for the substitution of Co than that of Mn展开更多
基金the Ministry of Science and Technology of China (Grant No. NKBRSF-G 19990646).
文摘The effect of Mg and C contents on TC in MgCN3, and structure and superconductivity of MgCNi3-x Co x were studied. It is found that the excess of Mg and C in initial material mixture is favorable to improvement inT c and helps to obtain single-phase samples. For preparing MgCNi3 superconductor, the optimum composition of starting materials is MgC1.45Ni3 with excess of Mg (20 wt.%) of the stoichiometric composition. In gCNi3-x Co x system, a continuous solid solution is formed, lattice parameter decreases slightly andT c decreases obviously with increasingx. A suppression of superconductivity is observed due to the substitution of Co (Mn) for Ni. The suppression effect is smaller for the substitution of Co than that of Mn
