title: Synthesis and characterization of the new two-dimensional Heisenberg antiferromagnet double perovskite BaLaCuSbO6.
abstract: The BaLaCuSbO(6) double perovskite has been successfully synthesized by solid state reaction under an air atmosphere. Its structure was refined using powder neutron diffraction in the monoclinic space group I2/m with a 4% antisite disorder on the B cations. Magnetic measurements give signs of 2D-antiferromagnetic behaviour with TN around 64 K. The Jahn-Teller distortion produced by Cu(2+) ions favours a crystallographic tetragonal distortion and consequently the in-plane super-superexchange antiferromagnetic interactions, J(90°), are favoured over the in-plane J(180°) antiferromagnetic exchange interactions. Both, J and J' magnetic interactions have been evaluated according to a Heisenberg antiferromagnetic rectangular model using an approximation to Curie's law in powers of J/T, being |J| around 10 times stronger than |J'|.
authors: INFIQC (CONICET-Universidad Nacional de Córdoba), Departamento de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre esq. Medina Allende, Ciudad Universitaria, X5000HUA Córdoba, Argentina. carbonio@fcq.unc.edu.ar.
authors: M Cecilia
authors: MC
authors: Blanco
authors: Sergio Alexis
authors: SA
authors: Paz
authors: Vivian M
authors: VM
authors: Nassif
authors: Julio J
authors: JJ
authors: Guimpel
authors: Raúl E
authors: RE
authors: Carbonio