Sol–gel synthesis of the magnetically frustrated oxides Sr2FeSbO6and SrLaFeSnO6

The use of the sol–gel synthesis method has been extended to include the preparation of stannates and antimonates from a citrate precursor. Samples of SrLaFeSnO6 and Sr2FeSbO6 have been prepared in a few hours. The structural and magnetic properties of the former are compared with those of a sample prepared over a period of several days by a solid-state route. The properties of Sr2FeSbO6 have been investigated by a combination of X-ray diffraction Mössbauer spectroscopy and SQUID magnetometry. The monoclinic perovskite structure has a partially (84%) ordered distribution of Fe and Sb cations over the six-coordinate sites; a transition to a magnetically frustrated phase occurs at 36 K.