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摘要
The non-isothermal kinetics of alpha ->beta transformation in La2Mo2O9 was investigated using the differential thermal analysis (DTA). The DTA curves were measured from the room temperature to 1 073 K at the heating rate of 10, 15, 20, 25 and 30 K.min(-1) respectively. The Flynn-Wall-Ozawa (FWO) method was used to determine the apparent activation energies of alpha ->beta transformation at different conversion rates. Then the values of activation energy obtained were adjusted using Ozawa iterative equation. The most probable mechanism functions were suggested by means of the Criado-Ortega and Satava-Sestak methods. The analysis of the present data shows that the activation energy changes with the change of conversion rate. This result indicates that the alpha ->beta transformation in La2Mo2O9 is not a simple reaction but a complex multi-step involving several processes. The most probable mechanism functions are different in various ranges of temperature, which are -ln(1-x) for 836 similar to 840 K, [-ln(1-x)](2/3) for 842 similar to 848 K and [-ln(1-x)](3/4) for 850 similar to 853 K respectively.
