,Epitaxial Properties of Co-Doped ZnO Thin Films Grown by Plasma Assisted Molecular Beam Epitaxy

• 作 者: CAO Qiang DENG Jiang-Xia LIU Guo-Lei CHEN Yan-Xue YAN Shi-Shen
• 机 构: School of Physics and Microelectronics, Shandong University, Jinan 250100“,”National Key Laboratory
• 出 处: 中国物理快报（英文版）
• 发表日期: 2007年10期

High quality Co-doped ZnO thin films are grown on single crystalline Al2O3(0001) and ZnO(0001) substrates by oxygen plasma assisted molecular beam epitaxy at a relatively lower substrate temperature of 450 ℃. The epitaxial conditions are examined with in-situ reflection high energy electron diffraction (RHEED) and ex-situ high resolution x-ray diffraction (HRXRD). The epitaxial thin films are single crystal at film thickness smaller than 500nm and nominal concentration of Co dopant up to 20%. It is indicated that the Co cation is incorporated into the ZnO matrix as Co2+ substituting Zn2+ ions. Atomic force microscopy shows smooth surfaces with rms roughness of 1.9nm. Room-temperature magnetization measurements reveal that the Co-doped ZnO thin films are ferromagnetic with Curie temperatures TC above room temperature.