溶胶-凝胶法制备Mg_xZn_(1-x)O及其特性

Preparation of Mg_xZn_(1-x)O by Sol-gel Method and Its Characteristics

采用溶胶-凝胶法制备了不同组分(x=0.1～0.3)的MgxZn1-xO前驱体,并对它进行不同温度的热处理(550℃～1000℃).X射线衍射(XRD)结果表明,Mg0.1Zn0.9O具有和ZnO一样的衍射谱,为六方纤锌矿结构,而且随着热处理温度的升高,ZnO衍射峰的强度逐渐增强,半高宽不断减小;Mg元素掺杂浓度增大后,出现了MgO的峰位.扫描电子显微镜(SEM)显示Mg0.1Zn0.9O晶粒粒径分布较均匀;热处理温度升高,晶粒的尺寸不断变大.用室温荧光光谱(PL)分析了经过550～1000℃热处理获得的Mg0.1Zn0.9O粉末,结果发现除了550℃下处理的样品,其它都有紫外发射峰(350nm左右),而且随着热处理温度的升高紫外峰有明显的蓝移现象.

MgxZn1-xOprecursors, in which x was from 0. 1 to 0.3 , were prepared by sol-gel method , then heat-treated at different temperatures. XRD showed that Mg0.1Zn0.9O powders possess a polycrystalline hexagonal wurtzite structure as well as ZnO. With the increase of heat-treating temperature, the intensity of diffraction peak increased and FWHM reduced. When x increased, MgO related peaks were found. The SEM images of Mg0.1Zn0. 9O powders were approximately spherical with a homogeneous distribution. The size becomes larger with the increase of temperature. The PL spectra of Mg0.1Zn0.9O powders at different heat-treating temperatures showed that all samples had an UV emission （350nm） except 550℃ and the emission band shifted progressively towards higher wavelength as the heat-treating temperature increased.