Structure-conductivity relationship of PrBaMnMoO6-δ through in-situ measurements: A neutron diffraction study

The structural and electrochemical properties of the double perovskite-type oxide, PrBaMnMoO6-δ, was investigated using neutron diffraction with in-situ conductivity measurement under a dry Argon atmosphere from 25 \ub0C to 700 \ub0C. A Rietveld refinement of the neutron diffraction data confirmed monoclinic symmetry in the P21/n space group. Rietveld refinement also confirms the unit cell parameters of a = 5.6567 (1) \uc5, b = 5.6065 (2) \uc5, c = 7.9344 (1) \uc5 and β = 84.43\ub0 with reliable atomic positions and refinement factors (R-factors). Neutron diffraction data refinement shows two minor phases (<5%), an orthorhombic AB2O5 type phase of PrMn2O5 in the Pbam (No. 32) space group with unit cell parameters, a = 7.9672 (1) \uc5, b = 8.9043 (2) \uc5 and c = 5.8540 (1) \uc5 and a scheelite phase of BaMoO4 in the tetragonal I41/a (88) space group with the unit cell parameters, a = b = 5.9522 (1) \uc5, and c = 12.3211 (2) \uc5. Morphological images revealed a porous and intertwined microstructure. In-situ conductivity measurement shows that the total conductivity of this material was 130.84 Scm−1 at 700 \ub0C