INFIQC   05475
INSTITUTO DE INVESTIGACIONES EN FISICO- QUIMICA DE CORDOBA
Unidad Ejecutora - UE
artículos
Título:
Synthesis, Structure and Magnetic Properties of La3Co2SbO9: A Double Perovskite with Competing Antiferromagnetic and Ferromagnetic Interactions
Autor/es:
DIEGO G. FRANCO; VALERIA C. FUERTES; M. CECILIA BLANCO; M. T. FERNÁNDEZ-DÍAZ; RODOLFO D. SÁNCHEZ; RAÚL E. CARBONIO
Revista:
JOURNAL OF SOLID STATE CHEMISTRY
Editorial:
ACADEMIC PRESS INC ELSEVIER SCIENCE
Referencias:
Lugar: San Diego; Año: 2012 vol. 194 p. 385 - 391
ISSN:
0022-4596
Resumen:
The synthesis, structural characterization,and magnetic properties of La3Co2SbO9 double perovskite are reported.The crystal structure has been refined by X-ray and neutron powderdiffraction data in the monoclinic space group P21/n. Co2+ and Sb5+ have the maximum order allowed for the La3Co2SbO9 stoichiometry. Rietveld refinements of powder neutron diffraction data show that at room temperature the cell parameters are a=5.6274(2) Å, b=5.6842(2) Å, c=7.9748(2) Å  and beta=89.999(3)o. Magnetization measurements indicate the presence of ferromagnetic correlations with TC=55K attributed to the exchange interactions for non-linear Co2+ ?O?Sb5+ ?O?Co2+ paths. The effective magnetic moment obtained experimentally is mu=4.38 mB (per mol Co2+), between the theoretical one for spin only (3.87 mB) and spin-orbit value (6.63 mB), indicating partially unquenched contribution. The low magnetization value at high magnetic field and low temperature (1 mB/f.u., 5T and 5K) and the difference between ZFC and FC magnetization curves (at5kOe) indicate that the ferromagnetism do not reach a long range order and that the material has an important magnetic frustration