文摘
La1鈥?i>xMgxO1鈥?xF2xBiS2 (x = 0.1鈥?.35) were synthesized, and their superconductive properties were investigated. The superconducting transition temperature (Tc) increased below the codoping level (x 鈮?0.25). La1鈥?i>xMgxOBiS2 (x = 0鈥?.2) and La1鈥?i>xMgxO0.6F0.4BiS2 (x = 0.1鈥?.3) were further prepared to explore the effect of Mg2+. We found that the introduction of Mg2+ and F鈥?/sup> leads to local structure distortion. Larger distortion is beneficial for superconductivity in LaOBiS2, which was further confirmed by the results in La1鈥?i>xCaxO1鈥?xF2xBiS2 (x = 0.2, 0.3).