Local Structure in Pure and Substitute Thin Films of High Tc Superconductors: an EXAFS Study

用EXAFS实验研究了YBa2Cu3O7(YBCO)和(La，Sr)2CuO4超导体薄膜的局域结构。通过测量c轴上的Cu(1)-O(4)和作为O的Cu(2)-O(4)键的行为，并通过退火在同一样品中重新引入，以确定非谐性如何随T_c变化。被取代的样品将被研究，以了解局部结构和位置、JC和准粒子寿命如何取决于不同的掺杂剂。这一点将通过c轴和a轴胶片得到澄清。由于低浓度区可能是控制或限制准粒子寿命的重要因素，因此将在块体YBCO中研究更多的Fe、Cu、Ni和Zn的稀释浓度。

The local structure in thin films of YBa2Cu3O7 (YBCO) and (La Sr)2CuO4 superconductors will be investigated using a series of EXAFS experiments. The behavior of the c-axis Cu(1)-O(4) and the Cu(2)-O(4) bonds as O is removed and reintroduced in the same sample via anneals will be measured to determine how the anharmonicity changes with Tc. Substituted samples will be studied to understand how the local structure and site, Jc, and quasiparticle lifetimes depend on different dopants. This will be clarified with c-axis and a-axis films. More dilute concentrations of Fe, Cu, Ni and Zn in bulk YBCO will be investigated as the low concentration regime may be important for controlling or limiting the quasiparticle lifetime.