Kinetics of Synthesis Nanophosphor Eu_(0.12)Y_(1.78)Ca_(0.10)O_(3-δ)

The nanophosphor Eu_(0.12)Y_(1.78)Ca_(0.10)O_(3-δ) was synthesized by homogeneous precipitation method under ul-trasonic condition.The structures,composition and morphology of the nanophosphor Eu_(0.12)Y_(1.78)Ca_(0.10)O_(3-δ) were characterized by X-ray diffraction(XRD),energy dispersive spectrometre(EDS),inductively coupled plasma atomic emission spectrometry(ICP-AES) and transmission electron microscope(TEM).The synthesis kinetics of nano-phosphor Eu_(0.12)Y_(1.78)Ca_(0.10)O_(3-δ) was investigated using differential thermal analysis and thermo gravimetric analysis(DTA-TG) at different heating rates in argon.The results show that the Eu0.12Y1.78Ca0.10O3-δ is body-centered-cubic-structured spherical nano-polycrytalline with grain size of 20nm.The precursor of nanophosphor Eu0.12Y1.78Ca0.10O3-δ is Y(OH)3 with hexagonal phase structure.The average apparent activation energy of the three reaction stages of precursor is calculated to be 102.06,488.00 and 302.74kJ/mol by using the Doyle-Ozawa and Kissinger methods,respectively.The reaction order and frequency factor are determined by Kissinger method.The kinetics equations of each reaction stage is deduced as dα/dt=8.86×108e-12280/T(1-α)1.36,dα/dt=4.05× 1033e-58700/T(1-α)1.32,dα/dt=7.14×1019e-36410/T(1-α)1.27.