Abstract

We obtained a Raman spectrum for a surface layer of porous carbon ceramic (porosity ≈5%) of ≈80 nm thick. The analysis of the spectrum showed that the ceramics contain crystals of silicon carbide 6H‑SiC and silicon. The destruction of ceramics by diamond microcrystals resulted in fractoluminescence (FL). Its spectrum contained two bands at 1.6 and 1.9 eV. The first is emerged at the destruction of silicon crystals, and the second is emerged at 6H-SiC crystals. We obtained the time dependence of the intensity of the fractoluminescence signals with a time resolution of 2 ns. Three types of signals were observed: one is formed when the 6H-SiC crystals are destroyed; the second is formed when silicon crystals are destroyed; the third is formed when these crystals are simultaneously destroyed. The appearance of signals is associated with the formation of cracks arising from the breakthrough of barriers formed at the intersection of slip planes of dislocations in silicon carbide and silicon crystals. The size of cracks in 6H-SiC has been estimated: the smallest is 5.5 nm, and the largest is ≈18 nm.

中文翻译：

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碳陶瓷破坏后纳米裂纹的形成与组织发光

摘要

我们获得了≈80nm厚的多孔碳陶瓷表面层（孔隙率≈5％）的拉曼光谱。光谱分析表明，陶瓷中含有碳化硅6 H -SiC和硅晶体。金刚石微晶对陶瓷的破坏导致了荧光发光（FL）。它的光谱包含1.6和1.9 eV的两个波段。第一个出现在硅晶体破坏时，第二个出现在6 H -SiC晶体中。我们获得了时间分辨率为2 ns的荧光发光信号强度的时间依赖性。观察到三种类型的信号：一种是在6 H-SiC晶体被破坏；第二种是在破坏硅晶体时形成的。当这些晶体同时被破坏时，形成第三种晶体。信号的出现与裂纹的形成有关，裂纹的形成是由于在碳化硅和硅晶体中的位错滑移面的相交处形成的势垒的突破而引起的。估计了6 H -SiC中的裂纹尺寸：最小为5.5 nm，最大为≈18nm。