Structural and magnetic properties of perovskite Ca3Fe2WO9

A complex perovskite with composition Ca3Fe2WO9 has been synthesised, and the temperature evolution of nuclear and magnetic structures investigated by neutron powder diffraction. It was shown that at room temperature this compound adopts a monoclinic perovskite structure belonging to space group P121/n1P121/n1 (a=5.4180(5)Å, b=5.5093(5)Å, c=7.7031(7)Å), β=90.04(2)°β=90.04(2)°). The partial B-site ordering, of the Fe+3 and W+6 cations, at (2c) and (2d  ) sites was determined. At low temperatures the magnetic diffraction peaks were registered and a possible model for the magnetic structure was proposed in accordance with the ferrimagnetic properties of the title compound. The magnetic structure is defined by a propagation vector k=(1/2,1/2,0)k=(1/2,1/2,0) and can be described as an array of ferromagnetic (20−1) layers, which couple antiferromagnetically to each other. All the Fe moments within a layer are aligned parallel (or anti-parallel) to the c-axis. The structural and magnetic features of this compound are discussed and compared with those of some other quaternary oxides A3Fe2WO9 (A=BaA=Ba, Sr, Pb).

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