Local Structure of Y1-xCaxBa2Cu4O8 Determined by XAFS

The local structure of YBa2Cu4O8 doped with Ca was studied by extended X-ray absorption fine structure (EXAFS) analysis. X-ray absorption measurements at the Ca K-edge indicate that Ca2+ ions substitute for Y3+ ions and are coordinated to eight oxide ions with a Ca–O distance of about 2.37 Å. The local structures around Ba and Cu atoms are also reported.