ABSTRACT

Pure, and doped with Al/Mn, ZnO nanoparticles were produced by the chemical co-precipitation method. X-ray diffraction analysis confirmed the hexagonal crystalline with wurtzite structure of pure and doped samples. Williamson-Hall (W-H) analysis was used to determine the crystallite size and micro-strains. The change in the bond length and lattice parameters of the doped ZnO confirms the incorporation of Al³⁺ ions to interstitial sites and Mn²⁺ ions to substitutional sites of ZnO lattice. UV-Visible spectroscopy has been used to study the change in the absorption edge after doping. Dielectric and conducting properties have been investigated and compared. Dielectric properties of doped samples have indicated the hopping mechanism liable for the change. Dielectric loss (tanδ) shows the opposite direction with frequency due to dielectric dispersion. The ac conductivity also indicated their variation after doping and is associated with an increase in the charge carrier and defects, which ultimately decides the overall change.

摘要

通过化学共沉淀法制备纯的、掺杂有 Al/Mn 的 ZnO 纳米颗粒。X射线衍射分析证实了纯样品和掺杂样品的具有纤锌矿结构的六方晶体。Williamson-Hall (WH) 分析用于确定微晶尺寸和微应变。掺杂 ZnO 的键长和晶格参数的变化证实了 Al ³⁺ 离子与间隙位点和 Mn ^{2+ 的结合} 离子到 ZnO 晶格的置换位点。紫外-可见光谱已被用于研究掺杂后吸收边的变化。已经研究和比较了介电和导电特性。掺杂样品的介电特性表明了导致这种变化的跳跃机制。由于介电色散，介电损耗 (tanδ) 显示出与频率相反的方向。交流电导率也表明了它们在掺杂后的变化，并且与电荷载流子和缺陷的增加有关，这最终决定了整体变化。