Magnetism and Superconductivity in under-doped region of T*-type La1-x/2Eu1-x/2SrxCuO4-yFy

We propose the muSR measurements on La0.91Eu0.91Sr0.18CuO4-yFy, which has CuO5 pyramid structure with five coordination of Cu ions, to investigate the ground state of the parent compound and the doping evolution of magnetism in T*-type cuprate. After the discovery of superconductivity in parent T’-type RE2CuO4 (RE = Rare earth) without cation substitution, the relationship between Cu coordination and the physical properties of lamellar cuprate oxide have been intensively studied. T*-type cuprate provides a unique opportunity to complement the lack of basic knowledge for this issue. However, no experimental study on magnetism in the under-doped region of T*-type cuprate has been reported. In this study, combined with the magnetic susceptibility measurement and our previous works, we complete the phase diagram for both as-sintere and oxygen annealed samples of T*-type cuprate.

本研究针对具有铜离子五配位特征的CuO5金字塔结构的La0.91Eu0.91Sr0.18CuO4-yFy开展缪子自旋共振（muSR）测量，以探究T*型铜氧化物的母体化合物基态及磁学性质的掺杂演化过程。在无需阳离子取代的T’型RE2CuO4（RE=稀土）母体化合物中发现超导电性后，学界针对铜离子配位环境与层状铜氧化物物理性质之间的关联展开了大量深入研究。T*型铜氧化物为弥补该领域基础认知的空白提供了独特的研究契机。然而，目前尚未有关于T*型铜氧化物欠掺杂区域磁学性质的实验研究报道。本研究结合磁化率测量与我们的前期工作，完整构建了T*型铜氧化物烧结态与氧退火处理样品的相图。