Molybdenum oxides have various crystal structures and physical properties due to the multiple valence states of the 4d molybdenum. Among them, MoO₂ has a distorted rutile structure with chemical stability and metallic behavior. In this study we grew epitaxial (100) MoO₂ thin films on (0001) Al₂O₃ substrates. Through careful control of the Ar-partial pressure and growth temperature, we determined the optimal growth condition. From our structural assessments, MoO₂ epitaxial thin films with high crystallinity can only be achieved in very narrow growth conditions such as 500 °C and 7 mTorr. The thin film prepared under optimal condition showed good metallic behavior, which was confirmed by electronic transport and optical reflectance measurements. A detailed electronic structure was also investigated by spectroscopic ellipsometry.

中文翻译：

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金红石型MoO ₂薄膜的 外延生长和金属化

由于4d钼的多价态，氧化钼具有各种晶体结构和物理性质。其中，MoO ₂具有扭曲的金红石结构，具有化学稳定性和金属行为。在这项研究中，我们在（0001）Al ₂ O ₃衬底上生长了外延（100）MoO ₂薄膜。通过仔细控制Ar分压和生长温度，我们确定了最佳生长条件。根据我们的结构评估，MoO ₂只有在非常狭窄的生长条件下（例如500°C和7 mTorr）才能获得具有高结晶度的外延薄膜。在最佳条件下制备的薄膜表现出良好的金属性能，这通过电子传输和光反射率测量得到证实。还通过椭圆偏振光谱法研究了详细的电子结构。