Ordered tetragonal spinel LiMnNbO4 prepared in reducing atmosphere

LiMnNbO4, the first quaternary compound in Li–Mn–Nb–O system, has been prepared by solid-state reaction in hydrogen atmosphere at 1050 °C. According to the X-ray Rietveld refinement results (R(F2)=0.0265, χ2=2.765), it is isostructural with LiZnNbO4: tetragonal, P4322, a=6.1858(1), c=8.5312(1) Å, Z=4, spinel-derived, with Li and Nb ordered on octahedral sites and with Mn in tetrahedral coordination.