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The growth of perylene on Ag (1 1 0) has been studied by ultraviolet photoemission spectroscopy measurements and low-energy electron diffraction. Four emission features of the organic material are located at 3.5, 4.8, 6.4 and 8.5 eV, respectively, below the Fermi level. An ordered structure of c(6×2) can be observed when the organic film is about a monolayer (3 A thickness). The angle-resolved ultraviolet photoemission spectroscopy measurements show that the molecular plane of perylene near the interface is parallel to the substrate. The desorption of the organic material occurs with warming the substrate; the perylene molecules are stable on the Ag (1 1 0) surface and no decomposition is observed below 140°C.

The stages of N , N- dialkyl-3,4,9,10-perylene tetracarboxylic diimide derivatives growth on Ru (0 0 0 1) surface has been studied with the ultraviolet photoemission spectroscopy measurements, three emission features of the organic material are located at 2.9, 4.8 and 6.7 eV, respectively below the Fermi level. The angle-resolved ultraviolet photoemission spectroscopy results suggest that the organic molecule is parallel to the substrate surface. Desorption of the organic material in multilayer occurs with warming the substrate. The decomposition of the adsorbed organic substance on Ru (0 0 0 1) surface is at roughly 125°C, the low decomposition temperature observed is attributed to the Ru substrate.

Growth of ordered perylene thin films on the Ag(110) surface has been investigated with scanning tunneling microscope. By saturating the surface with a monolayer of perylene molecules, two kinds of ordered structures are simultaneously formed with flat-lying perylene molecules on the Ag(110) surface, in which one is commensurate relative to the Ag substrate with a periodicity of (−2322) while the other is commensurate with a periodicity of (−2724). There is one molecule within the former unit cell with a surface coverage of 0.1 molecule per Ag atom, while there are two molecules within the latter unit cell, which gives a slightly lower surface coverage of 0.091 molecule per Ag atom. Ab initio calculations have been carried out to identify the adsorption geometry and bonding sites.

The structure of perylene adsorbed on Ru(0001) surface has been studied by ultraviolet photoemission spectroscopy (UPS) and low-energy electron diffraction. An ordered p(4x4) structure is observed from a monolayer (about 4 A thickness) of the perylene on Ru(0001) surface. UPS measurements show the molecular features, from the perylene multiplayer, between 2 and 10 eV below the Fermi level. Angle-resolved ultraviolet photoemission spectroscopy measurements suggest that the perylene molecular plane is parallel to the substrate. Temperature dependent UPS measurements show that the perylene multilayer is stable on Ru(0001) surface up to 125 degrees C. The desorption of the multilayer and the decomposition of the monolayer are observed above 125 degrees C.

We prepare a well-defined C84 monolayer on the surface of Ag (111) and study the geometric structure by scanning tunneling microscopy (STM). The C84 molecules form a nearly close-packed incommensurate R30° lattice. The lattice is long-distance ordered with numerous local disorders. The monolayer exhibits complex bright/dim contrast; the largest height difference between the molecules can be greater than 0.4 nm. Annealing the monolayer at 380 °C can desorb part of the molecules, but more than sixty percent molecules stay on the Ag (111) surface even after the sample has been annealed at 650 °C. Our analyses reveal that the 7-atom pits form beneath many molecules. Some other molecules sit at the 1-atom pits. Ag adatoms (those removed substrate atoms, accompanying the pit formation) play a very important role in this system. The adatoms can either stabilize or destabilize the monolayer, depending on the distribution manner of the adatoms at the interface. The distribution manner is determined by the co-play of the following factors: the dimension of the interstitial regions of the C84 overlayer, the number of the adatoms, and the long-distance migration of part adatoms.

The geometric and electronic structures at the interface between iron phthalocyanine (FePc) and Si(110) surface are studied by ultraviolet photoelectron spectroscopy and density functional theory (DFT) calculation. After FePc is deposited on Si(110), the emission features are located at 2.56, 4.90, 7.90, 10.88 eV below the Fermi level for monolayer and 2.73, 4.90, 7.74, 10.52 eV below the Fermi level for multilayer. At the coverage of 1 ML, FePc molecules are adsorbed on the bridge site in a flat-lying geometry with a 2.17 A separation between the molecule and the substrate. The molecular plane is bent due to the interaction between the adsorbate and the substrate.

We performed X-ray photoemission spectroscopy (XPS) investigation on the interface behavior at the Mn/PbTe(111) interface. The measurement shows the drastic changes at atomic level and the Mn/PbTe(111) interface formation. Upon Mn deposition, a new peak component associated with metallic Pb appears in the Pb core-level at low binding energies, and a new peak component related to MnTe compound appears in the Te core-level at high binding energies. These new features become more and more obvious in XPS spectra with increasing Mn thickness, and at the Mn thickness higher than 7 ML (beyond the escape depths of Pb and Te), the substrate features disappear. Upon further deposition of Mn, the intensity of the metallic Pb core level keeps constant, while the intensity of Te 3d core level of MnTe compound decreases with increasing Mn thickness, and finally the Te 3d core level disappears at Mn thickness of about 102 ML. Based on these results, we can conclude that, upon Mn depostion, both Te and Pb segregate to the surface region, the segregated Pb as metallic Pb floats on the top of Mn overlayer, and the segregated Te is bound in the Mn overlayer as MnTe.

The electronic states of tetracene adsorbed on Ru (1010) surface as well as their adsorption sites and directions has been studied by using ultraviolet photoelectron spectroscopy (UPS), angle-resolved ultraviolet photoelectron spectroscopy (ARUPS) and scanning tunneling microscopy (STM). The UPS measurements show that the six peaks from the tetracene are 2.1, 3.5, 4.8, 6.0, 7.1 and 9.2 eV below the Fermi level. The ARUPS measurements suggest that the plane of tetracene molecule is parallel to the Ru(1010) surface. The STM image shows that the tetracene molecule is adsorbed on Ru (1010) surface with its longer axis lying in the direction of either ［0001］ or ［1210］. The adsorption structure was confirmed with an ab initio calculation based on density functional theory (DFT). The short-bridge site and the hollow site are the most favorable sites when the molecule has its longer axis oriewted along ［0001］ and ［1210］, respectively.

The growth of perylene and tetracene on Ag (110) has been studied by the ultraviolet photoemission spectroscopy (UPS) and low-energy electron diffraction (LEED). The LEED results illustrate that an ordered C(6×2) structure can be observed when the thickness of perylene is about one monolayer (thickness of 03n m), and an ordered C (4×2) structure for tetracene with a thickness of one monolayer. From the measurements of UPS, four emission features of perylene are located at 35, 48, 64 and 85eV below the Fermi level respectively, and f our characteristic peaks, for tetracene, are located at 34, 49, 59 and 9 4 eV below the Fermi level. The angle_resolved ultraviolet photoemission spectro scopy measurements show that both perylene and tetracene near the interface are parallel to the substrate, the tetracene molecule is along ［110］ direction.

The potential and the electric field at the end of the individual nanowire under an electric field were calculated with the image charge model. With the nanowire as a field emitter, the enhancement factor was given by the expression: β０＝h/ρ+35. Taking into account the influence of the anode_cathode distance, the enhancement factor at the end of the nanowire could be adjusted based on the equation: β=h/ρ+35+A(h/d)3, where h and ρ are the length and the radius of the nanowire respectively; d is the anode_cathode distance and A is a constant. From the above results, it is concluded that the aspect ratio is the most important factor for the nanowire emitter and the anode_cathode distance also slightly influence the enhancement factor of the nanowire in field emission, and the enhancement factor increases with the decrease of the anode_cathode distance.

Scanning tunneling microscopy (STM) and x_ray photoemission spectroscopy (XPS) studies of germanium growth on Ru(0001) were carried out. STM measurements showed a typical Stranski_Krastanov growth mode of Ge on Ru(0001), i.e. first atomic wetting layer is formed in the submololayer range, and the formation of islands on top of a flat first layer occurs for subsequent layers. XPS measurements showed a weak interaction between Ge and the substrate of Ru(0001). The Ru 3d5/2 and Ru 3d3/2 corelevels of Ru(0001) are located at 2798 and 2840 eV in binding energy respectively. Upon Ge growth, up to a thickniss of about 20 atomic layers, the Ru 3d corelevels shift downward in binding energy by an amount of about 02 eV，while the Ge 3d corelevel shift upward in binding energy from the Ge low coverage limit of 289 eV to 290 eV，with a relative change of 01 eV.

Ultraviolet photoelectron spectroscopic(UPS) measurements of the tri (β-naphthyl) phosphine (TNP) film deposited on the Ag(110) surface were made. The TNP derived valence features are located at 38，63，93and 110 eV below Fermi level, and the top of the highest occupied molecular orbital(HOMO) of TNP is located at 25 eV in binding energy. The work function of Ag(110) is about 43 eV, and upon deposition of TNP, the work function decreases to the saturated value of 38 eV. Based on the UPS measurements, the energy level alignment at the interface of TNP/Ag(110) is given, and the results indicate a weak interaction between TNP and the Ag substrate.

利用UPS与ARUPS对有机半导体材料5-(N-正丁基-3，4，9，10-苝四甲酸亚酰胺-N’-苯基)-10，15，20-三苯基卟啉在Ru(0001)上的界面特性进行了研究．研究结果表明，在Ru(0001)表面上，与有机半导体材料价带电子轨道有关的谱峰分别位于费米能级以下4．5，6．8和9．2eV处，其最高占据态(价带顶位置)位于费米能级以下1．5eV处．在村底温度低于200℃时，该有机半导体材料能够在Ru(0001)上稳定吸附，在Ru(0001)上的脱附开始于在200℃．ARUPS结果显示，构成该材料分子的卟啉和苝两个稠环不在同一个平面内，即该材料分子中的两个稠环平面成一定的夹角至小右一个稠环平而与衬底表面不平行。

Yb-intercalated C60 thin film was prepared in a ultra-high-vacuum system. The binding energies of C 1s, Yb 4f and Yb 4d during the compound formation were studied by x-ray photoemission technique. The stoichiometry of the phase-pure sample was determined by the peak intensities of Yb 4f and C 1s. The result turned to be very near to that for Yb2.75C60 that was first determined for bulk-phase sample by x-ray diffraction measurement. The positions and intensities of the Yb 4f and Yb 4d peaks revealed the charge state of Yb2+ in Yb2.75C60. The C 1s core level for the phase-pure sample shifted towards lower binding energy by ≈0.5 eV relative to C60, which exhibited that some Yb 6s electrons transferred from Yb to the lowest unoccupied molecular orbital band of C60. The shift and the FWHM of C 1s x-ray photoemission spectroscopic peak can be used as sample characterization in future researches on Yb/C60 compounds.

The reaction between MgF2 and tris (8-hydroxy-quinoline)aluminum (Alq 3)has b een studied using high-resolution electron-energy-loss spectroscopy (HREELS).The reaction between MgF2 and Alq3 occurs in the cases of MgF 2 deposited on A lq3 and Alq3 on MgF2.The shift of the loss peak corresponding to the out-o f-plane ring bend is observed to be similar to that for Mg deposited on Alq 3.T he HREELS spectra indicate that Mg is produced from MgF2 deposited on Alq3,a nd interacts with Al,O and N in Alq3.Analysis of the HREELS results s uggests that Mg is not in the Alq3 molecule plane.

The ethylene(C2H4)adsorbed on Ru(0001)surface has been studied by using thermal desorption spectroscopy(TDS).The results show that ethylene(C2H4)absorbs in molecular state on Ru(0001)surface stably below 200 K.The dehydrogenation of ethylene occurs at 200 K.The main product of the dehydrogenation of the absorbed ethylene(C2H4)is acetylene(C2H2).There are two adsorption states of ethylene on the clean Ru(0001)surface.Their desorption temperature is 275 K and 360 K respectively.The desorption temperature of acetylene is 350 K.The desorption temperature of both acetylene and ethylene rises with increasing Cs coverage.

The ethylene (C2H4)and acetylene (C2H2)co-adsorbed with K on Ru(1010)surface has been studied by using ultraviolet spectroscopy(UPS).The results show that ethylene (C2H4) is absorbed in molecular state on Ru(1010)surface stably below 200 K.The dehydrogenated of ethylene occurs at 200 K.The main product of the dehydrogenation of the absorbed ethylene (C2H4)is the acetylene (C2H2).After the dehydrogenation of the absorbed ethylene(C2H4),the binding energies of σCC and σCH bonds have an increase of 0.2 eV and 0.5 eV respectively.The acetylene is absorbed in molecular state on Ru(1010)surface stably at room temperature.On a K pre-covered surface,the σCC peak disappears at room temperature.The element K promotes the dissociation of acetylene on Ru(1010)surface.

The ethylene (C2H4) adsorbed on Ru(1010) surface has been studied by X-ray photoelectron spectroscopy (XPS),thermal desorption spectroscop y (TDS) and ultraviolet photoelectron spectroscopy (UPS).The results show that e thylene absorbs in molecular state on Ru(1010) surface stably below 200K.The deh ydrogenation of ethylene occurs at 200K.The main product of the dehydrogenation of the absorbed ethylene is the acetylene (C2H2). After th e dehydrogenation of the absorbed ethylene,the C1s shifts 0.3eV to low binding e nergy level,and the binding energies of σCC and σCH bond have an increase of 0.5eV and 1.1eV respectively.

The C60 single crystals up to mm-size were grown. X-ray diffraction result shows that C60 single crystal is of fcc structure, with lattice parameter of 1.413 nm. An abrupt change of conductivity (at 251K) related to the phase transition shows that C60 single crystal is of high purity and homogeneity. A drop of activation energy around 274K was observed. This activation energy drop may be an indication of another phase transition.

The M?ssbauer spectra of the ferrite system, Li(0.5(1-x))ZnxFe(2.5-0.5x)O4, were studied at 77 K, 195 K and room temperature in an external magnetic field parallel to the gamma-ray direction. With increasing x and decreasing temperature, the second and the fifth lines of the six magnetic splittings were observed to become clearer, which proves convincingly the existence of canting of the moment of Fe3+ populated in the (B)-sublattice of the LiZn-ferrites. The agreement between magnetizations calculated on the basis of M?ssbauer parameters and measured by the magnetic experiment is satis-factory.