The Crystallinity of ices, amorphous and crystalline, can be altered not only by heat but also by irradiation of UV-rays or charged particles. In this work, the effect of UV-irradiation on the crystallinity of CO₂ ice was investigated by using a transmission electron microscope. A crystalline CO₂ ice was produced by annealing amorphous CO₂ ice. We found that UV-ray irradiation of CO₂ crystals at approximately 10 K does not cause amorphization in contrast to the reported amorphization of crystalline water ice below 70 K. We discuss the difference based on the expected UV photochemistry of CO₂ ice.

中文翻译：

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紫外线辐射永远不会导致结晶CO ₂非晶化：透射电子显微镜研究

冰的结晶度，无定形和结晶状，不仅可以通过加热来改变，而且可以通过紫外线或带电粒子的照射来改变。在这项工作中，通过使用透射电子显微镜研究了紫外线辐射对CO ₂冰的结晶度的影响。结晶CO ₂冰通过退火无定形CO产生₂冰。我们发现，与报道的低于70 K的结晶水冰非晶化相比，在大约10 K的紫外线照射下CO ₂晶体不会引起非晶化。我们基于预期的CO ₂冰的紫外线光化学讨论了这种差异。