Low-spin Mn3+ ion in rhombohedral LiMnO2 predicted by first-principles calculations

By means of first-principles calculations using spin-polarized generalized gradient approximation method, the Mn3+ ion in hypothetical rhombohedral LiMnO2 (r-LiMnO2) is predicted to be in an unusual low-spin state, i.e., all of its four 3d electrons occupy the three t(2g) levels, which makes r-LiMnO2 not only a good cathode material for rechargeable lithium-ion battery, but also a possible half-metal for spintronics. Following the proposed synthesis approaches deduced from the calculations, well crystallized r-LiMn0.65Cr0.35O2 is obtained through hydrothermal reaction and the low-spin state of the Mn3+ ion is verified by magnetic measurements.