| Research Abstract |
Angular resolved reflection high energy electron diffraction (AR-RHEED), which works in an extreme vacuum of 10^<-8>, has been designed and developed to study three dimensional structure of solid surfaces. The function and reliability of this AR-RHEED has been examined by using molybdenum disulfide (MoS_2) single crystal (0001), and clear streak patterns were obtained at every incident angles. Molecular beam epitaxially (MBE) grown C_<60> films on MoS_2 were prepared and analyzed by AR-RHEED.Superlattice structure of MBE grown C_<60>. with the van der Waals epitaxy, has been obtained. AR-RHEED showed that the MBE grown C_<60> had very smooth surface geometry from the onset of nucleation. The lattice constant of C_<60> is 1 nm, and thus AR-RHEED has an enough resolution to identify sub-nanometers. Surface structure of computer hard disks was tested for practical applications. Halo rings both from PFPE lubricant and from amorphous carbon were recognized. Due to the thickness of carbon films (l0nm), it was unable to detect magnetic storage media (sputtered CO-Cr-Ta-Pt). This implies that the present AR-RHEED is sensitive to surface. The detection of desorption mass spectroscopy of gases was attempted. However, to quantitatively identify F, C, 0 etc., re-design of pole piece of Q-mass was needed. Use of e-beam of the AR-RHEED as an energy loss spectroscopy required EELS spectrometer.
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