傅祖怡林文欽Fu, Tsu-YiLin, Wen-Chin許宏彰Hsu, Hung-Chang2019-09-052017-08-222019-09-052016http://etds.lib.ntnu.edu.tw/cgi-bin/gs32/gsweb.cgi?o=dstdcdr&s=id=%22G080041001S%22.&%22.id.&amp;http://rportal.lib.ntnu.edu.tw:80/handle/20.500.12235/102530無中文摘要Part I Silicene growth Using scanning tunneling microscopy (STM), we studied the formation of Si monolayer grown on (√3×√3)R30° Ag-Ge(111) and Ag-Si(111) reconstructed surface, respectively. Thereafter, we also increase Ag thickness, where is formed 6~12 ML Ag(111) layer, to grow silicene. On √3Ag-Si(111), deposited Si exchange with Ag atom to form the new √3Ag-Si(111) islands without forming new Si monolayer. On √3Ag-Ge(111), the Ag-Si exchange behavior is suppressed by stable bonding of Ag and below Ge(111) substrate. We measure the isolated Si monolayer with mixing √3×√3 and 2×2 superstructures on the top layer. From the demonstrated ball model, the Si monolayer found in this study is very possible to consist of honeycomb structure. On Ag(111)/Si(111) surface, we have measured classical silicene superstructures, such as 4×4, √13×√13-I, 2√3×2√3. Unlike growing on the single crystal Ag(111), where the discontinuous silicene sheet formed between various superstructures, the continuous silicene sheet formed between various superstructures on 6~10 ML Ag(111)/Si(111) by Ag domain rotation and shift because of low Ag(111) unstable on Si(111) substrate. Part II Iron growth In this part, we investigate Fe growth on various substrate, which are Fe/Si(111), Fe/√3Ag/Si(111), Fe/Ge(111), Fe/√3Ag/Ge(111), Fe/MoS2, and Pd/(Fe/Pd/C60)x/Au/Al2O3 system. In Fe/Si(111), we measured the thermal evolution of Fe-silicide from γ- FeSi2 to β- FeSi2, and -FeSi2 at the highest temperature by STM. In particular, the growth of β-FeSi2(011)//Si(111) is different with previous Fe-silicide studies. Besides, the isolated √3Ag-Si buffer layer causes the formation of -FeSi without appearing on Si(111) substrate at the same temperature. In Fe/Ge(111), the deposited Fe formed Fe-Ge clusters at RT. When Fe ratio is increased by increasing temperature, Fe-Ge clusters evolve into (2×2) islands, which alloy ratio between Fe1.5Ge to Fe2Ge. In addition, 3D islands forming at 640 K is considered as FeGe monoclinic structure. Besides, the number of √19 ring cluster defect increase to break the order c(2x8) reconstruction by increasing the temperature and disappeared at 640 K. With Ag buffer layer, only nanoparticle growth occurred and 3D islands were formed early at 570 K. In Fe/MoS2, we measured the surface morphology, magnetism and chemical states of Fe/MoS2 by STM, MOKE, and XPS, respectively. Fe deposition on the MoS2 substrate resulted in a nanoparticle array with the particle size ranged a few nanometer (). For low-coverage Fe deposition< 6 ML, nanoparticles were well-separated and long-range magnetic anisotropy was absent at room temperature. When the Fe coverage increased, in-plane magnetic anisotropy was observed and the magnetic coercivity increased monotonically. The depth-profiling XPS measurement of Pd/2 ML Fe/MoS2 also confirmed the dominance of the pure Fe state at the interface. The increase in Fe coverage changed the morphology from a nanoparticle array to a continuous coverage, leading to the onset of the ferromagnetic ordering and the transition from a continuous surface oxidation to a bilayer structure. At last, we report on the hybridization-induced large X-ray magnetic circular dichroism (XMCD) of carbon in Pd-Fe-C60 composite thin films. The samples were prepared by repeating sequential deposition of C60, Fe and Pd for five times on Au/Al2O3(0001) substrate in an ultrahigh vacuum (UHV) chamber. The Pd-Fe-C60 composite thin films were investigated by MOKE, XMCD, and Raman spectroscopy. The composite thin films revealed in-plane anisotropy. After annealing the sample at 527 K, the Kerr signal became weak and the magnetic coercivity was decreased. Then, considerable XMCD signal was observed at the carbon K-edge, but relatively small XMCD signal appeared at Fe L2,3-edge. In contrast to the XMCD spectrum of mixing transition metal and C60 system in previous study, we observed that the carbon will induce strong XMCD signal. These observations indicate the hybridization-induced magnetic moment in carbon and possible reduction of magnetization in Fe.矽烯鐵半導體二維材料鐵磁性siliceneironsemiconductor2D materialferromagnetic