Ion induced modification of size-selected MoO3 and WO3 clusters deposited on HOPG
Ion induced modification of size-selected MoO3 and WO3 clusters deposited on HOPG
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DOI：
10.1116/1.4711134
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发表时间：
2012-05
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影响因子：
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通讯作者：
Xiang Li;K. Wepasnick;Xin Tang;Yi Wang;K. Bowen;D. Fairbrother;G. Gantefoer
中科院分区：
文献类型：
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作者：
Xiang Li;K. Wepasnick;Xin Tang;Yi Wang;K. Bowen;D. Fairbrother;G. Gantefoer
利用x射线光电子能谱和原子力显微镜研究了4个keV Ar+离子对n = 30±1的高度有序热解石墨上（MoO3）n和（WO3）n簇沉积的影响。在沉积过程中，两种金属氧化物团簇在低覆盖率时优先聚集在台阶边缘，而在高覆盖率时，较大的团簇聚集在梯田上成核。在4kev Ar+离子轰击的影响下，两个团簇最初都经历了氧的损失和相应的过渡金属的减少，然后剩余的金属从表面溅射出来。然而，MoO3仅部分还原为MoO2，而WO3则完全还原为金属钨。由于这些离子诱导化学的变化，MoO3和WO3在长时间暴露于Ar+后表面形态的变化显著不同。当（MoO3）为30±1时，由于MoO2片段的去除，簇的大小减小。相比之下，（WO3）30±1时，形成较小的s…
The effect of 4 keV Ar+ ions on size-selected (MoO3)n and (WO3)n clusters, where n = 30 ± 1, deposited on highly ordered pyrolytic graphite was studied by x-ray photoelectron spectroscopy and atomic force microscopy. During deposition, both metal oxide clusters collected preferentially at step edges at low coverages, with larger cluster aggregates nucleating on the terraces at higher coverages. Under the influence of 4 keV Ar+ ion bombardment, both clusters initially experienced oxygen loss and corresponding reduction of the transition metal before the remaining species were sputtered from the surface. However, MoO3 was only partially reduced to MoO2, while WO3 was fully reduced to metallic tungsten. As a consequence of these variations in ion induced chemistry, changes in the surface morphology of MoO3 and WO3 following prolonged Ar+ exposure differed significantly. For (MoO3)30±1, the size of the clusters decreased, due to removal of MoO2 fragments. In contrast, for (WO3)30±1, the formation of smaller s...