Different response of superconductivity to the transition-metal impurities in K0.8Fe2-y-xMxSe2
Jul 26,2011|By Dian Tan, Changjin Zhang, Chuanying Xi, Langsheng Ling, Lei Zhang, Wei Tong, Yi Yu,1 Guolin Feng, Hongyan Yu, Li Pi, Zhaorong Yang, Shun Tan, and Yuheng Zhang. “Different response of superconductivity to the transition-metal impurities in K0.8Fe2-y-xMxSe2. PHYSICAL REVIEW B 84, 014502 (2011)
DOI: 10.1103/PhysRevB.84.014502
In this paper, we perform Fe-site substitution experiments onK 0.8 Fe 2？y Se 2 superconductor by choosing Cr, Mn, Co, and Zn as dopants. It is found that the doping of Cr, Co, and Zn leads to a drastic depression of superconductivity, while the introduction of Mn does not decrease the superconducting transition temperature (Tc) when x≤0.067. Electron-spin-resonance measurements reveal the existence of strong magnetic fluctuation in both the parent compound and the doped samples. In the Cr-, Co-, and Zn-doped samples, the magneticpair-breaking effect severely affects the superconductivity, resulting in drastic depression of superconductivity.On the other hand, in the Mn-doped case, it does not break the cooper pairs and thus hardly affects the Tc value.
