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通过结合纳米压痕和偏振拉曼散射技术对压应力影响下ZnO单晶晶格出现的变化进行了研究。位错的滑移是导致ZnO单晶中出现多处塑性变形的原因而非相变。之后采用偏振拉曼Mapping成像技术以E2(high)模为对象,监视其在整个压痕区内的强度变化分布。在压痕区中心累积的应力通过位错的滑移而释放,同时导致压痕区中心处的晶格畸变程度最为严重。伴随着晶格失配的加剧,拉曼选择定则放宽,在Z(XX)Z-配置下较弱的LO得到增强,原本非拉曼活性的B1(high)模出现。此外,在Z(XY)Z-偏振下压痕区左侧的拉曼光谱中观察到位于130cm-1处的拉曼异常振动模。此峰的出现可能与压痕区左侧由刃位错所形成的应力场吸引间隙离子导致的晶格畸变有关。
By combining the nanoindentation and polarized Raman scattering technique, the changes of the lattice of ZnO single crystal under the influence of compressive stress were studied. The slip of dislocations is the cause rather than the phase transition of the plastic deformation in the ZnO single crystal. After that, polarization Raman Mapping was used to measure the intensity distribution of E2 (high) mode in the entire indentation area. The accumulated stress in the center of the indentation zone is released by the slip of the dislocations, resulting in the most severe distortion of the lattice at the center of the indentation zone. With the increase of lattice mismatch, the Raman selection rule is relaxed. The weaker LO is enhanced under the Z (XX) Z-configuration and the original B1 (high) mode with non-Raman activity appears. In addition, a Raman anomalous vibration mode at 130 cm -1 was observed in the Raman spectrum on the left of the indentation region in Z (XY) Z-polarization. The appearance of this peak may be related to the lattice distortion induced by the interstitial ions induced by the stress field formed by the edge dislocations on the left of the indentation area.