Phase transformations in h-MoO₃ microrods have been locally induced by laser irradiation and assessed in situ by micro-Raman and photoluminescence spectroscopy. The obtained phases and their time stability were found to depend on laser wavelength, power density and irradiation time. Red laser (633 nm) irradiation induces the stable formation of α-MoO₃. The corresponding oxidation dynamics appear to be triggered by diffusion processes. Considering the diverse physical properties of the different Mo oxides, red laser irradiation appears as a suitable method to tailor the functionalities of individual h-MoO₃ microstructures. UV (325 nm) irradiation also transforms h-MoO₃ into α-MoO₃, with the formation of Mo₄O₁₁ being observed in the initial stage of the irradiation process. However, this transformation seems to be unstable in time, finally giving rise to structural changes in the obtained α-MoO₃ phase and to the appearance of other Mo oxides. Laser irradiation also modifies the luminescence properties of the h-MoO₃ microrods, giving rise to the appearance of several emission bands related to complex defects involving oxygen vacancies.

中文翻译：

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六角形MoO ₃微型棒中激光辐照引起的相变的原位局部评估†

h-MoO _3微棒中的相变已通过激光辐照局部诱导，并通过微拉曼光谱和光致发光光谱法进行了原位评估。发现所获得的相位及其时间稳定性取决于激光波长，功率密度和照射时间。红色激光器（633纳米）照射诱导α-的MoO的稳定形成₃。相应的氧化动力学似乎是由扩散过程触发的。考虑到不同的Mo氧化物的不同物理特性，红色激光辐照似乎是调整单个h-MoO ₃微观结构功能的合适方法。UV（325 nm）的照射也变换的h-的MoO ₃为α-的MoO ₃，在辐照过程的初始阶段观察到Mo ₄ O ₁₁的形成。然而，这种转变似乎是不稳定的时候，最后引起在所获得的α-的MoO结构变化₃相和其他钼氧化物的外观。激光辐照还改变了h-MoO _3微棒的发光特性，出现了与涉及氧空位的复杂缺陷有关的几个发射带的出现。