排序方式: 共有13条查询结果,搜索用时 31 毫秒
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Heinrich BW Limot L Rastei MV Iacovita C Bucher JP Djimbi DM Massobrio C Boero M 《Physical review letters》2011,107(21):216801
Low-temperature scanning tunneling microscopy and spectroscopy combined with first-principles simulations reveal a nondissociative physisorption of ferrocene molecules on a Cu(111) surface, giving rise to ordered molecular layers. At the interface, a 2D-like electronic band is found, which shows an identical dispersion as the Cu(111) Shockley surface-state band. Subsequent deposition of Cu atoms forms charged organometallic compounds that localize interface-state electrons. 相似文献
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EP Sheretov VS Gurov MV Dubkov OV Korneeva 《Rapid communications in mass spectrometry : RCM》1999,13(16):1699-1702
In this article we compare the classical monopole mass filter of von Zahn and the monopole mass filter with a hyperbolic V-shaped electrode. The experimental results and those of computer simulation for both mass spectrometers are presented. We show that the replacement of a conventional 90 degrees V-shaped electrode by an electrode with a hyperbolic profile substantially improves the peak shape of any given mass, and increases the mass resolution by a factor of 3-4 and the abundance sensitivity by a factor of 100. The potential of high analytical performance combined with electroforming techniques for electrode manufacture indicate future practical uses of such instruments. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
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Low-temperature scanning tunneling microscopy and spectroscopy are employed to investigate electron tunneling from a C60-terminated tip into a Cu(111) surface. Tunneling between a C60 orbital and the Shockley surface states of copper is shown to produce negative differential conductance (NDC) contrary to conventional expectations. NDC can be tuned through barrier thickness or C60 orientation up to complete extinction. The orientation dependence of NDC is a result of a symmetry matching between the molecular tip and the surface states. 相似文献
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B. W. Heinrich C. Iacovita M. V. Rastei L. Limot P. A. Ignatiev V. S. Stepanyuk J. P. Bucher 《The European Physical Journal B - Condensed Matter and Complex Systems》2010,75(1):49-56
During recent years the surface electronic states of cobalt nanoislands grown on Cu(111) and Au(111) have been extensively
studied and still yield fascinating results. Among magnetic surfaces, cobalt islands are particularly appealing because of
their spin-polarized electronic states near the Fermi energy, involving localized d states of minority character, as well
as free-like s–p states of majority character. We show here that these states are a sensitive probe to minute changes of structural
details such as strain and stacking, and therefore constitute an ideal playground to study the interplay between structural
and spin-related properties. Due to their size, cobalt islands on Cu(111) offer the additional opportunity to host single-magnetic
adsorbates suitable for spin-polarized scanning tunneling microscopy and spectroscopy (SP-STM and SP-STS). We establish here
that, in an energy interval just below the Fermi level, the spin-polarization of a transition-metal atom is governed by surface-induced
states opposite in sign compared to the island, while the spin-polarization of Co-Phthalocyanine molecules is governed by
molecular states. This opens up interesting perspectives for controlling and engineering spin-polarized phenomena at the nanoscale. 相似文献
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DC magnetization, neutron depolarization and neutron diffraction (with both polarized and unpolarized neutrons) measurements
have been reported for the Co1.1−x
Zn
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Ge0.1Fe1.2O1 spinels with x=0.5, 0.6 and 0.7. Neutron depolarization and neutron diffraction measurements confirm the presence of a long range ferrimagnetic
ordering of the local canted spins in these ferrite samples. The observed features of low field magnetization have been explained
under the framework of thermally activated domain wall movement of ferrimagnetic arrangement of local canted spins. An important
role of magnetic anisotropy (due to the presence of Co2+ ions) in establishing the magnetic ordering and domain kinetics in these ferrites has been observed. 相似文献
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MV Muftakhov YV Vasil'ev VA Mazunov 《Rapid communications in mass spectrometry : RCM》1999,13(12):1104-1108
Appearance energies of [M-H](-) ions from carbonyl compounds R-CO-R' (R,R' = H, CH(3), NH(2), OH) have been measured by means of negative ion mass spectrometry in resonant electron capture mode. Values of electron affinity of the corresponding radicals, CH(2)&dbond;C(X)O, NH&dbond;C(X)O and O&dbond;C(X)O, have been determined. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
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Rastei MV Heinrich B Limot L Ignatiev PA Stepanyuk VS Bruno P Bucher JP 《Physical review letters》2007,99(24):246102
Low-temperature scanning tunneling spectroscopy over Co nanoislands on Cu(111) showed that the surface states of the islands vary with their size. Occupied states exhibit a sizable downward energy shift as the island size decreases. The position of the occupied states also significantly changes across the islands. Atomic-scale simulations and ab initio calculations demonstrate that the driving force for the observed shift is related to size-dependent mesoscopic relaxations in the nanoislands. 相似文献