Zhan Wei, Kosinskiy Andrey Yurievich, Vines Lasse, Johansen Klaus Magnus, Carvalho Patricia Almeida, Prytz Øystein
Department of Physics, Centre for Materials Science and Nanotechnology, University of Oslo, N-0316 Oslo, Norway.
SINTEF Materials and Chemistry, NO-0314 Oslo, Norway.
Materials (Basel). 2019 Mar 16;12(6):888. doi: 10.3390/ma12060888.
The ZnCr₂O₄/ZnO materials system has a wide range of potential applications, for example, as a photocatalytic material for waste-water treatment and gas sensing. In this study, probe-corrected high-resolution scanning transmission electron microscopy and geometric phase analysis were utilized to study the dislocation structure and strain distribution at the interface between zinc oxide (ZnO) and embedded zinc chromium oxide (ZnCr₂O₄) particles. Ball-milled and dry-pressed ZnO and chromium oxide (α-Cr₂O₃) powder formed ZnCr₂O₄ inclusions in ZnO with size ~400 nm, where the interface properties depended on the interface orientation. In particular, sharp interfaces were observed for ZnO [2113]/ZnCr₂O₄ [110] orientations, while ZnO [1210]/ZnCr₂O₄ [112] orientations revealed an interface over several atomic layers, with a high density of dislocations. Further, monochromated electron energy-loss spectroscopy was employed to map the optical band gap of ZnCr₂O₄ nanoparticles in the ZnO matrix and their interface, where the average band gap of ZnCr₂O nanoparticles was measured to be 3.84 ± 0.03 eV, in contrast to 3.22 ± 0.01 eV for the ZnO matrix.
ZnCr₂O₄/ZnO材料体系具有广泛的潜在应用，例如，作为用于废水处理和气体传感的光催化材料。在本研究中，利用探针校正的高分辨率扫描透射电子显微镜和几何相分析来研究氧化锌（ZnO）与嵌入的锌铬氧化物（ZnCr₂O₄）颗粒之间界面处的位错结构和应变分布。球磨并干压的ZnO和氧化铬（α-Cr₂O₃）粉末在ZnO中形成了尺寸约为400 nm的ZnCr₂O₄夹杂物，其界面性质取决于界面取向。特别是，对于ZnO [2113]/ZnCr₂O₄ [110]取向观察到了清晰的界面，而ZnO [1210]/ZnCr₂O₄ [112]取向则显示出跨越几个原子层的界面，位错密度很高。此外，采用单色电子能量损失谱来绘制ZnO基体中ZnCr₂O₄纳米颗粒及其界面的光学带隙，其中测得ZnCr₂O纳米颗粒的平均带隙为3.84±0.03 eV，而ZnO基体的平均带隙为3.22±0.01 eV。
