Influence of the B-site ordering on the magnetic properties of the new La3Co2MO9 double perovskites with M = Nb or Ta

V.C. FUERTES; M.C. BLANCO; D.G. FRANCO; J.M. DE PAOLI; R.D. SÁNCHEZ; R.E. CARBONIO

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2011 vol. 46 p. 62 - 62

p class="MsoNormal" style="text-align: justify; line-height: 200%; margin: 0cm 0cm 0pt;">Double perovskites La3Co2NbO9 and La3Co2TaO9 have been prepared by both solid state and sol-gel synthesis. The crystal structures have been studied from X-ray and neutron powder diffraction data. Rietveld refinements show that the crystal structure is monoclinic (P21/n), with different degrees of ordering of B´ and B´´ cations, with octahedra tilted according to the Glazer notation a-b-c+. Occupancy refinements show that the solid state materials are more B-site ordered than the sol-gel ones. Magnetization measurements show that these perovskites show two magnetic contributions, one with spontaneous magnetization and other with linear behaviour with the magnetic field associat