posted on 2006-03-20, 00:00authored byHouria Kabbour, Laurent Cario
We have designed new compounds within the homologous series Ae2F2M1+nX3+n (Ae = Sr, Ba; M = main group
metal; n = integer) built up from the stacking of 2D building blocks of rock salt and fluorite types. By incrementally
increasing the size of the rock salt 2D building blocks, we have obtained two new n = 1 members of this homologous
series, namely, Sr2F2Sb2Se4 and Ba2F2Sb2Se4. We then succeeded in synthesizing these compounds using a
high-temperature ceramic method. The structure refinements from the powder or single-crystal X-ray diffraction
data confirmed presence of the expected alternating stacking of fluorite [Ae2F2] (Ae = Sr, Ba) and rock salt [Sb2Se4]
2D building blocks. However the Ba derivative shows a strong distortion of the [Sb2Se4] block and a concomitant
change of the Sb atom coordination likely related to the lone-pair activity.