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本文利用X-射线光电子能谱仪、X-射线衍射仪和电子显微镜对不同化学计量比的MoS_2表面氧化行为进行了研究。结果表明,完整的MoS_2(002)表面在350℃时的热稳定性能良好,即使在450℃下于短时间内也未发生明显的氧化,这与它有序的原子排列结构有关;然而一旦破碎就表现出与单晶表面不同的化学稳定性,甚至在室温就发生表面氧化;MoS_2(002)经60°倾角入射的Ar~+刻蚀微细化可使表面积增大,容易与空气中的氧反应生成稳定的钼的氧化物;天然MoS_2单晶的S、Mo原子比约为1.8∶1.0,经反复摩擦后S、Mo原子比发生了变化,生成非化学计量比的MoSx(x<1.8),Mo~(4+)向较低化学价态转变,致使MoSx的Mo原子有更多的悬空链,这是导致表面氧化失效的化学因素。
In this paper, X-ray photoelectron spectroscopy, X-ray diffraction and electron microscopy were used to study the surface oxidation behavior of MoS 2 with different stoichiometry. The results show that the thermal stability of intact MoS_2 (002) surface is good at 350 ℃, and there is no obvious oxidation even at 450 ℃ in a short period of time, which is related to its ordered atomic structure. However, It shows different chemical stability with the single crystal surface, even at room temperature on the surface oxidation; MoS_2 (002) incident angle of 60 ° Ar ~ + etching micronization can increase the surface area, easy and oxygen in the air The reaction results in a stable molybdenum oxide. The atomic ratio of S and Mo of natural MoS 2 single crystal is about 1.8: 1.0. After repeated friction, the atomic ratio of S and Mo changes to produce non-stoichiometric MoSx (x <1.8) , Mo ~ (4 +) to the lower chemical valence state, resulting MoSx Mo atoms have more dangling chains, which is the chemical factors that lead to the surface oxidation failure.