Abstract
The tetragonal bulk superconductor CaLaBaCu3O7 is obtained from YBa2Cu3O7 by the replacement of Y by La and some of the Ba by Ca. Its detailed structure, particularly the cation site occupancy, is uncertain.
We have made EXAFS measurements on the edges of all four cations, Ba, Ca, Cu and La to determine the local environment of each and attempt to determine the site occupancies and to construct a possible structure, including local distortions.