[16a-D505-1~11] 16.1 Fundamental properties, evaluation, process and devices in disordered materials

△ [16a-D505-7] Evaluation of MnO₆ Octahedral Distortion in LiMn₂O₄ by RMC Method

〇Masatsugu Yoshimoto¹, Kazuhiko Omote¹ (1.Rigaku)

Keywords:RMC method, local structure, total scattering

In the original reverse Monte Carlo (RMC) method, the periodic term S^P(Q) cannot calculate from the atomic coordination because the RMC is performed by the finite dimension of the calculation box. To estimate the local structure in a crystalline material, we proposed the RMC method which added the new algorithm to calculate the periodic term S^P(Q) from observed data S_obs(Q). We applied the proposed RMC to LiMn₂O₄ which is one of the most famous cathode materials of Li-ion battery. The valence of Mn-ion is determined from the estimated structural model by the bond valence sum (BVS) method. The angular histogram of the regular octahedron shows a peak at θ = 90°, but the angular histogram of Mn³⁺O₆ shows a peak less than θ = 90° and a wider distribution than that of Mn⁴⁺. It is suggested that the Mn³⁺O₆ octahedra is more distorted than the Mn⁴⁺O₆ octahedra. We will discuss the more detailed results in the presentation.