The control of physical properties through cation ordering in perovskites often gives rise to unexpected and desirable functionality. Of particular interest in the preparation of cation ordered materials are phases that result from the intergrowth of two different simpler structures. Notably, the structure of Y1.1Ca2.3Ba1.6Fe5O13 can be derived from the intergrowth of YBa2Fe3O8 and Ca2Fe2O5. We have developed this chemistry by synthesising the following three new series of samples;1. Cation and oxygen vacancy ordered Y1+yCa4-x-yBaxFe5O13 phases2. Cation ordered Y1+yCa4-x-yBaxFe5O15 perovskites (by topochemical oxidation of the above materials).3. Cation disordered Y0.2Ca0.8-xBaxFeO3 perovskites (disordered analogues of the above materials)We request 3 days on WISH to record diffraction patterns of 12 samples (4 from each series), each ≈1 g.