Local Distortions in Isovalent Doped LaNbO4

This study will use total neutron scatting methods to characterise the local structure of oxide ion conductions of the type La1-xVxO4. Rietveld analysis of constant wavelength neutron diffraction data reveals a surprising volume increase upon V substitution despite its smaller ionic radius, which, from XAS measurements, remains +5 across the series. Bond Valence Sum calculations using the average structure reveal considerable underbonding of the V cations. Nb L-edge XAS measurements suggest a gradual disordering of the Nb cations, accompanied by a change in coordination. This work will shed light on the complex interplay between composition, structure, and bonding in these oxides.