The crystallization of ZnO prepared by sol–gel technique was investigated under nonisothermal conditions by differential scanning calorimetry (DSC) and prediction isothermal method. The transformation from the amorphous to crystalline state was investigated by X-ray diffraction (XRD). The influence of the annealing temperature on the structure of the ZnO was studied by Filed Emission Scanning Electron Microscopy (FESEM) and Atomic Force Microscopy (AFM). Two exothermic changes were reported between the temperature ranges 590–710 K and 645–750 K for first and second transition, respectively. The isoconversional methods of Friedman, Ozawa and Flynn and Wall (FWO), Kissinger–Akahira–Sunose and the Vyazovkin (minimizing) were used to determine the variation of the effective activation energy with the extent of crystallization, E_α (α) and hence, with temperature E_α (T). In addition, the activation energy was calculated from predicted isothermal results. Analysis of the obtained data shows that the activation energy of crystallization is not constant but varies with the degree of conversion and, hence, with temperature. The value of the local Avrami exponent, n (α), varies within 1.88–1.97 for isothermal study and within 2.35–2.4 for nonisothermal process. By using the Johnson–Mehl–Avrami (JMA) model, a good fit was achieved between experimental and theoretical calculation of the reaction (crystallization) rate. The optical energy gap decreased with increasing annealing temperature.

通过差示扫描量热法（DSC）和预测等温法研究了在非等温条件下通过溶胶-凝胶技术制备的ZnO的结晶。通过X射线衍射（XRD）研究了从非晶态到结晶态的转变。通过场发射扫描电子显微镜（FESEM）和原子力显微镜（AFM）研究了退火温度对ZnO结构的影响。据报道，在第一次和第二次转变之间，温度范围分别在590-710 K和645-750 K之间有两个放热变化。弗里德曼（Friedman），小泽（Ozawa）和弗林（Flynn）和沃尔（FWO），基辛格（Kissinger-Akahira）-苏纳斯（Sunose）和Vyazovkin（最小化）的等转换方法用于确定有效活化能随结晶程度的变化，È _α（α），因此，随着温度È _α（Ť）。另外，由预测的等温结果计算活化能。对获得的数据的分析表明，结晶的活化能不是恒定的，而是随转化度而变化，因此随温度变化。等温研究的局部Avrami指数n（α）的值在1.88–1.97之间，非等温过程的变化在2.35–2.4之间。通过使用Johnson-Mehl-Avrami（JMA）模型，在实验和理论计算的反应（结晶）速率之间实现了很好的拟合。光能隙随着退火温度的升高而减小。