Phase Transition of Li2O–Fe2O3 System. II. Thermal and Electric Properties of Lithium Ferrospinel LiFe5O8

The measurements of differential thermal analysis, thermal expansion and d. c. electric resistance for lithium ferrospinel were performed ; the results were discussed in relation to these for the lithium ferrite. Conclusions are as follows; (1) Anomalous changes in the thermal and the electric properties take place during the transition and the hysteresis loops are observed. (2) The transition temperature for LiFe5.86.O8, 745±1°C., is obtained from both thermal and electric measurements. The true transition temperature is determined to be 750±1°C. for the stoichiometric specimen. (3) It is verified that the transition velocity is more rapid than that of lithium ferrite. (4) The thermal properties change at the magnetic Curie point, ca. 635°C.