Nouvelles familles de phases MIMII2Nb3O10 a feuillets “perovskites”

A new series of phases MICa2Nb3O10 (MI = Li, Na, K, Rb, Cs, NH4, Tl) has been prepared and characterized. Their unit cells are tetragonal. The structures consist of treble perovskite sheets interleaved with MI sheets. According to the MI nature, the relative displacement of adjacent treble perovskite sheets, parallel to (001) is O, b4 or (a + b)4