ABSTRACTThe local structure around Ba atoms in the compound superconductor Y-Ba-Cu-O has been studied by measuring the extended x-ray absorption fine structure (EXAFS) near the Ba K edge. This technique is used to investigate the changes in the short range order structure when the system is doped with impurities.
AbstractShort-range order in the oxygen co-ordination shell of the Ca ion in a glass of composition Ca3Mg4Al2Si7O24 is investigated by analysis of the extended X-ray absorption fine structure. The estimate of disorder in the short-range oxygen co-ordination is no greater than that for crystalline samples of diopside and bytownite. An estimate of the oxygen environment of calcium in the particular glass is included.