Synthesis and characterisation of the 1113 family of cuprates

A series of rare earth cuprates crystallising in the 1113 structure similar to CaBaLaCu 3 O 7 were synthesised and characterised. The compounds CaBaRCu 3 O x (R=La, Pr, Nd and Sm) formed in single phase whereas compounds with the other rare earths were not single phase and resulted in the formation of the 123 phase together with other impurity phases. The stability of the 1113 phase was found to be very sensitive to the preparative conditions and the size of the rare earth ion.