Anomalous properties of A_m−1Bi₂B_mO_3m+3 layered ferroelectrics

ISSN： 0020-1685

Source： Inorganic Materials, Vol.42, Iss.11, 2006-11, pp. : 1236-1242

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Abstract

Statistical analysis is presented of the literature data on the properties of A_m−1Bi₂B_mO_3m+3 layered ferroelectrics consisting of alternating perovskite-like slabs and bismuth-oxygen layers. The results reveal new and confirm some of the known tendencies. The Bi-O layers are shown to tighten the structure of these compounds, and the effect becomes stronger with decreasing slab thickness. As the distortion of the pseudoperovskite cells in the perovskite-like slabs increases, the Curie temperature T _C passes through a maximum. Its position depends on the slab thickness (m). Thus, at strong lattice distortions, T _C decreases with increasing distortion, in conflict with the Abrahams-Kurtz-Jamieson relation. The observed anomalies are tentatively attributed to changes in the nature of ion displacements.