View Publication | CEMHTI CNRS UPR3079 Orléans France

M.Allix, P.D.Battle, P.P.C.Frampton, M.J.Rosseinsky, R.Ruiz-Bustos, 'Composition dependence of the structural chemistry and magnetism of Ca2.5Sr0.5(Ga,Co)1+xMn2-xO8', J. Solid State Chem. 179 775 (2006) doi:10.1016/j.jssc.2005.11.037

Polycrystalline samples of bilayered brownmillerite-like Ca2.5Sr0.5GaCo0.15Mn1.85O8 and Ca2.5Sr0.5Ga1.2Mn1.8O8 have been prepared and characterised by magnetometry and neutron diffraction over a wide temperature range. The structural chemistry and magnetic properties are compared to those of Ca2.5Sr0.5GaMn2O8. Ga enrichment has a significant effect on the former but not on the latter, whereas changes in both occur when paramagnetic Co3+ cations enter the parent phase on the 4-coordinate sites. The coupling between the environment around the 4-coordinate cations and the transition to an antiferromagnetic ordered state that was observed in Ca2.5Sr0.5GaMn2O8 is not apparent in the cation-substituted compositions, although both show long-range antiferromagnetic order at low temperatures.