Low-Temperature Structure and Magnetic Properties of the Spinel LiMn2O4: A Frustrated Antiferromagnet and Cathode Material

Powder neutron diffraction has been used to study the nature of the structural transition away from the Fd3m cubic structure upon cooling below ∼285 K in the spinel LiMn2O4. We report powder data taken between 10 K and 333 K and propose a large cell tetragonal structure in space group I41/amd for the material at 100 K. While complete segregation of the Mn3+ and Mn4+ ions is not possible in this space group, bond-valence analysis indicates that …