Synthesis and structures of lithium manganese oxide spinel, LiMn 2O 4− δ (0≤ δ≤0.27)

Abstract

Lithium manganese oxides spinels were synthesized under various synthesis conditions and their structures were determined by TOF neutron powder diffraction measurements. Oxygen vacancies exist for the samples synthesized above 800°C, and the amount of vacancies was found to be sensitive to the synthesis conditions. The nearly stoichiometric spinels were synthesized at 750°C in O 2 followed by heating at 470°C. The transition temperatures of the cubic–orthorhombic transitions and the magnetic properties varied with the compositions. The stoichiometric spinel showed no cubic–orthorhombic phase transition.