Ruddlesden-Popper phase

Ruddlesden-Popper (RP) phases are a type of perovskite structure that consists of two-dimensional perovskite-like slabs interleaved with cations. The general formula of an RP phase is An+1BnX3n+1, where A and B are cations, X is an anion (e.g., oxygen), and n is the number of octahedral layers in the perovskite-like stack.[1] Generally, it has a phase structure that results from the intergrowth of perovskite-type and NaCl-type (i.e., rocksalt-type) structures.

These phases are named after S.N. Ruddlesden and P. Popper, who first synthesized and described a Ruddlesden-Popper structure in 1957.[2][3]

The unit cell of Ruddlesden-Popper phases (a) Sr2RuO4 (n = 1) and (b) Sr3Ru2O7 (n = 2). The polyhedra are part of the perovskite-like layers. In these examples A = A’ = Sr2+.
  1. ^ Wells, A.F. (1984). Structural Inorganic Chemistry. Oxford: Clarendon. p. 602. ISBN 0-19-855370-6.
  2. ^ Ruddlesden, S.N.; Popper, P. (1958). "The compound Sr3Ti2O7 and its structure". Acta Crystallogr. 11: 54–55. doi:10.1107/S0365110X58000128.
  3. ^ Ruddlesden, S.N.; Popper, P. (1957). "New compounds of the K2NiF4 type". Acta Crystallogr. 10 (8): 538–539. doi:10.1107/S0365110X57001929.