Aurivillius phases

Aurivillius phases are a form of perovskite represented by the general formulae is (Bi₂O₂)(A_n−1B_nO_3n+1) (where A is a large 12 co-ordinate cation, and B is a small 6 co-ordinate cation).

Basically, their structure is built by alternating layers of [Bi₂O₂]²⁺ and pseudo-perovskite blocks, with perovskite layers that are n octahedral layers in thickness.^[1] This crystal structure was first described in 1949 by B. Aurivillius.^[2] The first interest in Aurivillius phases arose from the observation of ferroelectricity even for the simplest member, Bi₂WO₆ (n=1) of this crystallographic family. The Mo-homologous Aurivillius phase Bi₂MoO₆ was recently investigated as a potential LTCC material. Their oxide ion-conducting properties of Aurivillius phases were first discovered in the 1970s by Takahashi et al., and they have been used too for this purpose ever since.^[3]

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