抄録
The orthorhombic Pmnb phase of Li2MnSiO4 has been prepared by solid state reaction of Li2CO3, Mn(CH3COO)2⋅4H2O, and highly dispersed SiO2 at 800 °C and the subsequent slow cooling in Ar gas stream. The crystal structure was refined by the Rietveld method based on the model structure without disorder in the site occupancies, although some anomaly was observed for Mn sites. The DTA curve shows peaks at around 680 and 770 °C on heating and at around 510 °C on cooling indicating a reversible structural phase transition. From the in-situ XRD patterns at high temperature, the first order phase transition from Pmnb to a distorted orthorhombic wurzite-type structure with the random arrangement of Li, Si, and Mn.
