This was a little surprising given the significant reduction in cell volume across the series from La -Pr- Nd. In addition to little change in transition temperature there was also little change to the degree of tetragonality. Similarly little change was observed for the A3Hf2Li7O12 (A = La, Pr, Nd) series, although here the smaller Hf appears to have led to a small increase in the phase transition temperature to ~650 -700°C. Therefore, it appears that doping on the A site has minimal effect on the phase transition, hence suggesting a direct relation to cell volume is too simplistic, as volume considerably reduces across these series of samples.