Effect of Rare Earth on iron-based supercnducting RE0.18Ca0.82(Fe0.92Co0.08As)2 single crystal

• Main Authors: Shan-Sing Syu, 許善興
• Other Authors: Ming-Der Lan
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/55082987209728342634

碩士 === 國立中興大學 === 物理學系所 === 102 === Magnetism and superconductivity(SC) are two outstanding quantum phenomena, and the relationship between the magnetic and superconducting orders has naturally become an important subject in condensed matter physics. So we focus on iron-based superconductors. In general belief that the superconductivity is highly correlated to the FeAs layer in the iron-based superconductors. Other layer compounds only offer electronic for intermediate layer. Antiferromagnetic fluctuations are likely to play an integral role in the superconducting pairing process. The parent of the long-range antiferromagnetic ordering repression, superconductivity will often show up. So we speculate that the rare-earth-doped after the elements, caused by changes in the lattice structure may indirectly inhibit the generation of long-range magnetic order. This experiment was to investigate the effects of doping on RE0.18Ca0.82(Fe0.92Co0.08As)2. When the rare earth doped materials will change the lattice constant which is the impact of the formation of the superconducting properties one of the reasons. So we use XRD analyzer to compare its lattice constant after doping and the use of Closed Cycle Refrigerator Systems measure its electrical resistance. The other part is the use of magnetic MPMS do the analysis, we can know whether there is totally anit-magnetic. And we can change the lattice length number generated for the superconducting properties for it or not, to do a detailed comparison.