N. S. P. Bhuvanesh, M. P. Crosnier-Lopez, H. Duroy and J. L. Fourquet
Several new members (n = 2, 3, 4 members) of the family of layered perovskites Li2[AxBnO3n + 1] (A = Ca, Sr, La; B = Nb, Ta, Ti, Fe) have been synthesized for the first time. The structure analysis of Li2SrNb2O7 and Li2SrTa2O7 determined by powder X-ray diffraction (XRD), and of Li2La1.78Nb0.66Ti2.34O10 and Li2Sr2Nb3.97Fe0.03O12.97 determined by single crystal XRD data, shows that these novel phases are related to the Ruddlesden–Popper series of compounds, A′2[An – 1MnO3n + 1]. While the structures of n = 2 members are identical to the RP series, in the higher members the A sites are partially occupied. Interestingly, the compounds for A = Ca, Sr and B = Nb, Ta, Fe indicate the formation of a new family of oxides of general formula Li2A0.5nBnO3n + 1 where different members of the family can be synthesized with the same set of A and B atoms.