Lattice effects in cubic La2Mo2O9: Effect of vacuum and correlation with transport properties

This study aims to investigate correlations between lattice effects and transport properties in cubic La2Mo2O9. High temperature neutron diffraction data, recorded in air and under vacuum, are used to follow the evolution with temperature of selected structural parameters, i.e. bond lengths and angles. Results suggest a possible correlation with the experimentally observed decrease of the activation energy for oxygen migration at high temperature. The effect on the structural properties of the low oxygen partial pressure used during the measurements in vacuum is negligible and this represents a valuable information in view of possible applications of the material in solid state devices. - Graphical abstract: Anti-tetrahedral unit centred in O1 and linked through La ions to form a cage where the partially occupied O2 and O3 ions are placed