We have recently observed unusual magnetostrictive behaviour in Bi0.5La0.5FeO3 (BLFO), a phenomenon which is not present in either solid solution end member. This proposal seeks to further our understanding of the mechanism of this behaviour by carrying out two complementary experiments on two instruments: 1) a zero field, high resolution study on HRPD of the structural evolution and distortion mechanisms in LaFeO3 (LFO) as a function of temperature to complement our BiFeO3 (BFO) and BLFO data from previous ISIS experiments; and 2) a magnetic field and temperature dependent study of BLFO on GEM/WISH to investigate anisotropic lattice strain as a function of magnetic field.