Non-isothermal kinetics study with isoconversional procedure and DAEM: Thermal decomposition of LaPO4:Ce,Tb center dot 0.5H(2)O

作者：Li, Yu; Chai, Qian; Liao, Sen^*; Chen, Zhipeng; He, Yu; Xia, Yao; Wu, Wenwei; Li, Bin

来源：Materials Chemistry and Physics, 2013, 142(2-3): 453-458.

DOI：10.1016/j.matchemphys.2013.05.030

• Inorganic compounds
• Optical materials
• Chemical synthesis
• Thermogravimetric analysis (TGA)
• Luminescence

The precursor, La0.9Ce0.05Tb0.05PO4 center dot 0.5H(2)O was synthesized via solid-state reaction at 333 K. The experimental results show that the synthesized product is orthorhombic La0.9Ce0.05Tb0.05PO4 center dot 0.5H(2)O, and monoclinic La0.9Ce0.05Tb0.05PO4 is a green emitting phosphor which can be obtained after calcining La0.9Ce0.05Tb0.05PO4 center dot 0.5H(2)O at 973 K in air. Based on the iterative isoconversional procedure, the values of activation energy E-alpha associated with the Region I and Region II of the thermal decomposition of the precursor were obtained, which demonstrates that the Region II is a kinetically complex process, and the Region I is a single-step kinetic process and can be described by a unique kinetic triplet [E-alpha, A and g(alpha)]. The most probable reaction mechanism of the Region I was estimated by the comparison between experimental plots and modeled results. The value of pre-exponential factor A of the Region I was obtained on the basis of E-alpha and the reaction mechanism. The distributed activation energy model (DAEM) was applied to study the Region II.

• 出版日期2013-11-15
• 单位广西大学