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利用金属有机源化学气相沉积(MOCVD)技术,在蓝宝石上外延了Mn-N共掺ZnO薄膜,同时,将得到的ZnMnO:N样品分别在700,900和1100°C的温度下进行真空退火处理.X射线衍射(XRD)显示真空退火使薄膜样品的晶格质量变差,但样品都具有良好的单轴取向.ZnMnO:N样品的拉曼光谱(Raman)和光致发光谱(PL)光学表征显示真空退火使得样品中氧空位(VO)增多.对NT,Mn共掺ZnO晶体的第一性原理模拟计算揭示了N,Mn共掺ZnO的态密度存在较强的p-d相互作用,产生磁矩.一旦引入氧空位(VO)后,费米能级上移,p-d相互作用消失,磁矩减小甚至消失.实验表征分析与模拟计算结果一致:对于N,Mn共掺ZnO薄膜样品,引入氧空位(VO)后,铁磁性减弱.因此,Mn3d电子与N2p局域束缚的电子形成的磁性束缚激子(BMP)决定了磁性相互作用的产生.
Mn-N codoped ZnO thin films were epitaxially grown on sapphire by MOCVD. At the same time, the obtained ZnMnO: N samples were vacuum annealed at 700, 900 and 1100 ° C. X X-ray diffraction (XRD) showed that the vacuum annealing improved the lattice quality of the films, but the samples had good uniaxial orientation.The Raman and PL spectra of the ZnO samples showed a vacuum Annealing results in an increase in the oxygen vacancy (VO) in the sample. A first-principles simulation of NT and Mn codoped ZnO crystals reveals that the density of N and Mn co-doped ZnO has a strong pd interaction and a magnetic moment. After the introduction of oxygen vacancies (VO), the Fermi level shifts up and the pd interaction disappears and the magnetic moment decreases or even disappears.The experimental characterization results are consistent with the simulation results: for the N and Mn codoped ZnO thin films, oxygen vacancy ( VO), the magnetic confinement excitons (BMPs) formed by Mn3d electrons and N2p localized electrons determine the magnetic interaction.