Effect of Oxygen Vacancies on the Mechanoluminescence Response of Magnesium Oxide
Effect of Oxygen Vacancies on the Mechanoluminescence Response of Magnesium Oxide
复制标题
氧空位对氧化镁机械发光响应的影响
DOI：
10.1021/acs.jpcc.0c07674
复制
发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Graeve, Olivia A.
中科院分区：
文献类型：
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作者：
Novitskaya, Ekaterina;Manheim, Aaron;Herrera, Manuel;Graeve, Olivia A.
氧化物材料的机械致发光响应对于这些材料在结构健康监测应用中的使用具有影响，在结构健康监测应用中需要监测裂纹扩展。因此，我们描述了 MgO 粉末的机械发光，表明信号取决于氧空位的存在。粉末的阴极发光 (CL) 光谱显示出与 F+ 中心（氧空位）相关的 2.10 eV 发射，以及与 M+ 和 M– 中心（成对氧空位）相关的 3.70 和 4.10 eV 强 CL 发射。此外，CL 测量显示发射频率为 1.70 eV，该发射不受机械应力的影响，可归因于激发态和基 F+ 态之间的电子跃迁。通过X射线光电子能谱和电子能量损失谱证实了氧空位的存在。相对于电子照射时间的CL强度的测量证实了大量F+中心的存在，以及饱和时间效应，其中发射强度仅在照射一定时间后才达到最大值。这种饱和效应的存在与机械发光信号相关。
The mechanoluminescence response of oxide materials has implications for the use of these materials in structural health monitoring applications, where crack propagation needs to be monitored. Thus, we describe the mechanoluminescence of MgO powders, showing that the signal is dependent on the existence of oxygen vacancies. Cathodoluminescence (CL) spectra of the powders exhibited an emission at 2.10 eV associated withF+centers (oxygen vacancies), as well as intense CL emissions at 3.70 and 4.10 eV, associated withM+andM–centers (paired-oxygen vacancies). Furthermore, CL measurements revealed an emission at 1.70 eV, which was not influenced by mechanical stress and can be attributed to an electronic transition between excited and groundF+states. The presence of oxygen vacancies was confirmed by X-ray photoelectron spectroscopy and electron energy loss spectroscopy. Measurements of CL intensity with respect to electron irradiation time confirmed the presence of high amounts ofF+centers, as well as a saturation time effect in which emission intensity achieves a maximum only after a certain time of irradiation. The existence of this saturation effect was correlated to the mechanoluminescence signal.