Structural properties, magnetic and oxygen-vacancies order in Y(Ba 1-xSrx)Co2O5.5 layered cobaltites

Abstract

We present a study of the family Y(Ba1-xSrx)Co 2O5.5 (x = 0, 1/8, 1/4, 1/3, 3/8, 1/2). The complex magnetic behavior characterizing the parent (x = 0) compound and other RBaCo2O5.5 compounds can still be guessed in M(T) curves of x = 1/8 compound, but it disappears under substitution of Ba by Sr for all the studies cases (x ≥ 1/8). This is linked to the fact that the order of oxygen vacancies is lost, as found by neutron and synchrotron X-ray powder diffraction. © 2010 IOP Publishing Ltd.