Дисертації з теми "Platinum (111)"
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Furman, Scott Anthony. "Surface chemistry of iodine on platinum (111)." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ36639.pdf.
Повний текст джерелаSun, Grace Siswanto. "Simulations of platinum growth on Pt(111) using density functional theory and kinetic monte carlo simulations /." Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/9672.
Повний текст джерелаShiller, Paul Joseph. "Reactions of methanol and carbon monoxide on ad-atom modified platinum(111) and molybdenum(110) surfaces: Molecular orbital study." Case Western Reserve University School of Graduate Studies / OhioLINK, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=case1055946339.
Повний текст джерелаZheng, Chaozhi. "Coverage, step and quantum effects on surface diffusion of H on Pt(111) surfaces /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?PHYS%202004%20ZHENG.
Повний текст джерелаLoh, Andrea. "Study of the adsorption and reaction of 1-epoxy-3-butene on platinum(111)." Connect to online resource, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1447652.
Повний текст джерелаYim, Chi Ming. "LEEM investigations of adsorption and diffusion of CO on the Pt(111) surface /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?PHYS%202007%20YIM.
Повний текст джерелаIhm, Hyeran. "Thermal activation and intermediates of six-membered cyclic hydrocarbons and alkyl nitrites on Pt(111) and Cu(100) /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.
Повний текст джерелаRidley, Paul. "Underpotential deposition of lead on gold and platinum (111) electrode surfaces investigated by scanning tunnelling microscopy." Thesis, University of Liverpool, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343615.
Повний текст джерелаGómez, Marín Ana María. "Role of Surface Species at Pt(111) in Electrochemical Oxygen Reduction." Doctoral thesis, Universidad de Alicante, 2014. http://hdl.handle.net/10045/42320.
Повний текст джерелаDen, Boef Martinus. "Assessment of the national DSM potential in mine underground services / M. den Boef." Thesis, North-West University, 2003. http://hdl.handle.net/10394/111.
Повний текст джерелаThesis (Ph.D. (Mechanical Engineering))--North-West University, Potchefstroom Campus, 2004.
Mane, Mane. "Adsorption des hydrocarbures insaturés (éthylène et propylène) sur la surface Pt(111) nue et en présence de coadsorbats (alcalins, oxygène, alcalins oxydés) : étude par AES, TDS, UPS, XPS et NEXAFS." Nancy 1, 1993. http://www.theses.fr/1993NAN10062.
Повний текст джерелаEL, ACHI RAMAL. "Oxydation electrocatalytique du methanol en milieu acide sur des surfaces de platine a marches pt(s)n(111)(111)=pt(s)(n-1)(111)(110)." Paris 6, 1993. http://www.theses.fr/1993PA066083.
Повний текст джерелаBrunat, William-Luc. "Cristallographie de surface par diffraction de photoélectrons de haute énergie cinétique (XPD) : CoSi2(111), Pt(110) et Pt50Ni50(110)." Lyon 1, 1992. http://www.theses.fr/1992LYO10188.
Повний текст джерелаAumer, Andreas. "Summenfrequenzerzeugungsspektroskopie an Metallen,Oxiden und oxidgeträgerten Metallpartikeln." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2010. http://dx.doi.org/10.18452/16158.
Повний текст джерелаThis thesis focuses on 4 different model systems of surface science. The experimental techniques used for the measurements include sum frequency generation (SFG), thermal desorption spectroscopy (TDS), low energy electron diffraction (LEED), Auger electron spectroscopy (AES), infrared adsorption spectrosocopy (IRAS) and scanning tunneling microscopy (STM). By using SFG, measurements could be performed up to a pressure of 50 mbar. The systems under investigation were: CO on Pt(111), water on Ag(001) and on MgO/Ag(001), CO on Au/MgO/Ag(001), and CO on Au-Pd/MgO/Ag(001). The system of CO on Pt(111) exhibits a two peak-pattern under certain pressure and temperature conditions which has not been studied so far. Various experiments helped to elucidate the origin of this distinct behaviour. The measurements of water on Ag(001) and MgO/Ag(001) show that on MgO, water first adsorbs as a monolayer with a following multilayer, whereas on Ag(001) it adsorbs as a multilayer from the beginning. The monolayer can be studied below the multilayer and some resonances can be identified. For the case of Au/MgO/Ag(001), STM shows that the growth mode of Au depends on the thickness of the supporting MgO film, which can not be seen with spectroscopic methods. For mixed Au-Pd particles on MgO/Ag(001) a clear difference in the adsorption behaviour between pure metal particles and mixed particles can be seen, which is explained by an interaction between these metals. Annealing the mixed particles to 600 K leads to a segregation of the metals, where the Au atoms diffuse to the shell and the Pd atoms make up the core. The results of all these measurements are discussed in the light of recent publications.
Sachs, Christian. "Untersuchung von Reaktionsmechanismen auf Oberflächen mittels Rastertunnelmikroskopie: zur Wasserstoffoxidation auf den Oberflächen Platin(111) und Rhodium(111)." [S.l.] : [s.n.], 2001. http://www.diss.fu-berlin.de/2001/253/index.html.
Повний текст джерелаNiedermayer, Thomas Philipp. "Nichtthermische und thermische Desorption von Helium auf Pt(111)." [S.l. : s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=965396592.
Повний текст джерелаBattirola, Liliane Cristina. "Modificação de membranas de Nafion® 117 com nanopartículas de \'PT\' e \'PT\'-\'RU\' para aplicação em células a combustível." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/88/88131/tde-21072011-103643/.
Повний текст джерелаBeyond the necessity of the development of new electrocatalysts for fuel cell application, there is also the necessity of diminishing of the crossover that compromises the oxidation efficiency of the fuel. So, in this work was carried out the doping of the Nafion® 117 membranes with \'PT\' and \'PT\'/\'RU\' nanoparticles in two different platinum concentrations by using the absorption-reduction method. The Atomic Absorption results and the color of the samples proved that the absorption of the metallic precursor solutions by the membrane happened. FTIR-ATR and XRD data showed the formation of nanoparticles. It was observed that in unitary fuel cells (PEMFC, DMFC and DEFC) tests the PEMFC and DEFC showed an improvement in the efficiency. Although a significant increase in the power density, up to 50 % by using doped membranes, it was not possible to eliminate the crossover. However, in the case of the DEFC, a high percentage of oxidized products with two carbon atoms was found in the cathode exit. The main formed products were acetaldehyde and acetic acid, being the acetic acid the majority product. Traces of formic was also detected demonstrating that, in lesser scale, the break of the C-C bond is feasible. Moreover, the results showed that the durability of the doped Nafion® membranes is higher than the membrane without metallic particles, since bigger current densities were reached in the former case. Finally, the membrane doping and the temperature rise led the DEFC to the best performance.
Paulino, Marcia Elizangela. "\"Estudo da reação de eletro-oxidação de metanol sobre eletrodos monocristalinos de platina modificados com eletrodepósitos de cobre e estanho\"." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/75/75131/tde-12042007-094545/.
Повний текст джерелаMethanol oxidation reaction was studied with copper and tin modified single-crystal electrodes. This study was carried out using UPD and OPD techniques using the EDRMP configurations the results showed that the coverage degree of copper and tin on platinum single-crystal as less than one monolayer (_ 10% monolayer) and possible with the formation of islands in bi and tridimenision. The deposition of copper was not good to the methanol oxidation reaction, possible due to a higher solvatation by anions at the Cu sites, conducting to a blocking effect on the Pt neighboring atoms. The tin deposition have shown a higher activity for methanol oxidation reaction. This ascribed to the hydroxides formation at tin sites, which increase the kinetics of CO oxidation following the bifunctional mechanism.
Robinson, Andrew William. "Adsorption on platinum (110) : reflection-absorption infra-red studies." Thesis, University of Bath, 1988. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379555.
Повний текст джерелаGrant, Ann W. "Surface studies of model catalysts using metal atoms and particles on ZnO(0001)-Zn and -O and TiO₂(110) /." Thesis, Connect to this title online; UW restricted, 2001. http://hdl.handle.net/1773/8499.
Повний текст джерелаVölkening, Stephan. "Untersuchungen von Reaktionsmechanismen auf Oberflächen mittels Rastertunnelmikroskopie die atomar aufgelösten Oxidationsreaktionen von Kohlenmonoxid und Wasserstoff auf Platin(111) /." [S.l. : s.n.], 1999. http://www.diss.fu-berlin.de/1999/10/index.html.
Повний текст джерелаBeccat, Pierre. "Structure et composition superficielles de l'alliage Pt80Fe20(111) en liaison avec ses propriétés catalytiques." Grenoble 1, 1990. http://www.theses.fr/1990GRE10043.
Повний текст джерелаMoré, Sam Dylan. "Untersuchungen von Adsorbaten auf Einkristalloberflächen mittels Beugung niederenergetischer Elektronen Koadsorption von K und CO auf Pt(111) ; Li, Na, K auf Pt111) ; N auf Cu(110) sowie Untersuchungen von der reinen Ga(001)-Oberfläche /." [S.l. : s.n.], 1998. http://www.diss.fu-berlin.de/1998/14/index.html.
Повний текст джерелаBlais, Sonia. "Étude du comportement électrochimique de couches inorganiques ultra-fines sur l'électrode de platine (111)." Sherbrooke : Université de Sherbrooke, 2000.
Знайти повний текст джерелаBerner, Ulrich. "Struktur und Reaktivität ultradünner Ceroxidschichten auf Pt(111)-Einkristalloberflächen Untersuchungen mit Rastertunnelmikroskopie, Photoemission und IR-Reflexions-Absorptions-Spektroskopie /." [S.l.] : [s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=964801884.
Повний текст джерелаOstermann, Dieter. "STM-, XPS-, LEED- und ISS-Untersuchungen an reinen und Pd-bedeckten ultradünnen Titanoxidschichten auf Pt(111)." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=97774292X.
Повний текст джерелаRöder, Holger. "Microscopic processes in heteroepitaxial growth : nucleation, growth and alloying of silver on the (111) surface of platinium /." [S.l.] : [s.n.], 1994. http://library.epfl.ch/theses/?nr=1288.
Повний текст джерелаPeronio, Angelo. "A closer look at heterogeneous catalysis: reaction intermediates at the single-molecule level." Doctoral thesis, Università degli studi di Trieste, 2013. http://hdl.handle.net/10077/8577.
Повний текст джерелаThe present work pertains to the surface science approach to heterogeneous catalysis. In particular model systems for CO2 hydrogenation to methanol, and NO selective catalytic reduction, are investigated by means of a combined approach, where the molecular-level insight provided by a low-temperature scanning tunneling microscope is complemented by density functional theory (DFT) calculations of their electronic structure. To this end, the Inelastic Electron Tunneling Spectroscopy (STM-IETS) technique was introduced for the first time in our laboratory, a recent development which allows to measure the vibrational spectrum of individual molecules adsorbed on a surface. Regarding CO2, we provide single molecule imaging and characterization of CO2/Ni(110), chemisorbed with high charge transfer from the substrate, in an activated state that plays a crucial role in the hydrogenation process. We obtain a detailed characterization of the adsorption geometries and an estimate of the energies corresponding to the different adsorbed states. A consistent picture of CO2 chemisorption on Ni(110) is provided on the basis of the newly available information, yielding a deeper insight into the previously existing spectroscopic and theoretical data. In the Selective Catalytic Reduction (SCR) process, nitrogen oxide is selectively transformed to N2 by reductants such as ammonia. The specificity of this reaction was tentatively attributed to the formation of NH3-NO coadsorption complexes, as indicated by several surface science techniques. Here we characterize the NH3-NO complex at the atomic scale on the (111) surface of platinum, investigating the intermolecular interactions that tune the selectivity. The structures that arise upon coadsorption of NH3 and NO are analyzed in terms of adsorption sites, geometry, energetics and charge rearrangement. An ordered 2 × 2 adlayer forms, where the two molecules are arranged in a configuration that maximizes mutual interactions. In this structure, NH3 adsorbs on top and NO on fcc-hollow sites, leading to a cohesional stabilization of the extended layer by 0.29 eV/unit cell. The calculated vibrational energies of the individually-adsorbed species and of the coadsorption structure fit the experimental values found in literature within less than 6%. The characterizations and optimizations that had to be tackled in order to successfully perform STM-IETS measurement are eventually presented, focusing in particular on an original method which allows to increase the achieved resolution. Namely, the modulation broadening associated to phase-sensitive detection is reduced by employing a tailored modulation function, different from the commonly-used sinusoid. This method is not limited to STM-IETS, but can be easily applied whenever a lock-in amplifier is used to measure a second derivative.
XXV Ciclo
1984
THIELE, JORG. "Structure et proprietes magnetiques de couches minces de cobalt sur la face (111) du platine." Paris 11, 1995. http://www.theses.fr/1995PA112292.
Повний текст джерелаDonev, Jason Matthew Kaiser. "Non-contact atomic force microscopy studies of amorphous solid water deposited on Au(111) /." Thesis, Connect to this title online; UW restricted, 2003. http://hdl.handle.net/1773/9779.
Повний текст джерелаPollmann, Michael. "Musterbildung bei der CO-Oxidation auf Pt(110) unter gezielter Beeinflussung." [S.l.] : [s.n.], 2002. http://www.diss.fu-berlin.de/2002/71/index.html.
Повний текст джерелаFolkuenig, Engelbert de Souza. "Investigação teórica da quimisssorção do ânion metanossulfonato em eletrodos de platina (111) e (100) via método semi-empírico." UNIVERSIDADE ESTADUAL DE PONTA GROSSA, 2010. http://tede2.uepg.br/jspui/handle/prefix/2085.
Повний текст джерелаSeveral electrochemical processes, such as electrocatalysis of organic substrates, make use of mediators. One of the mediators is the most commonly used anion methanesulfonate, CH3SO3, which has several advantages for such use, and chemical stability considered one of them. However, experimental studies indicate the possibility of this compound suffer the adsorption and decomposition on platinum electrodes. To get an understanding at the molecular level these processes, computer simulations were performed with the aid of the semi-empirical PM6. The cluster approach was used in the modeling of platinum surfaces with crystallographic orientations (111) and (100). The symmetries of most stable adsorption calculated for the anion in these areas correspond to the experimental data: C3V symmetry in (111) surface and C1 in (100) surface. To simulate the potential applied to the electrode, external electric fields with a positive sign and perpendicular to the surface of the clusters were applied. Changes in the lengths and angles of bonds adsorbed anion, as well as its values of dipole moment were observed. The infrared spectra of the systems anion-clusters were calculated and the values for the Stark tunning rate (Δstark) of mode δs CH3 were compared with the experimental value. Both for the free anion and for systems where the anion is adsorbed, it was found that the values of Δstark assumed negative values (indicating that the frequency of the vibrational mode δs CH3 diminished with increasing external eletric field), opposite to the experimental positive value (frequency mode δs CH3 increases with the increase in potential). Only with the addition of water molecules in the systems studied, in order to simulate the aqueous solvent is that the values of Δstark started to assume a positive value. The comparison showed the importance of the presence of water molecules in the simulation of an electrochemical system and prompted a detailed analysis of the frontier orbitals involved in this process. It was found that the dipole-dipole coupling between water molecules and the adsorbed anion is responsible for the Stark effect, while the electrostatic interactions between various molecules adsorbed anion affect the intensity of the absorption band mode δs CH3 in the spectra calculated. In (100) surfaces, the joint action of external field and water molecules, lead the anion molecule to adopt the adsorption geometries more inclined to systems without water molecules, indicating that this may be an important factor in explaining the greater reactivity of the anion on the surface.
Vários processos eletroquímicos, como por exemplo a eletrocatálise de substratos orgânicos, fazem uso de mediadores. Um dos mediadores mais utilizados é o ânion metanossulfonato, CH3SO3¯, que apresenta várias vantagens para tal uso, sendo a estabilidade química considerada uma delas. No entanto, estudos experimentais apontam para a possibilidade desse ânion sofrer processos de adsorção e decomposição em eletrodos de platina. Para se obter uma compreensão em nível molecular desses processos, simulações computacionais foram efetuadas com auxílio do método semi-empírico PM6. A aproximação de cluster foi utilizada na modelagem de superfícies de platina com orientações cristalográficas (111) e (100). As simetrias de adsorção mais estáveis calculadas para o ânion nessas superfícies correspondem aos dados experimentais: simetria C3v em superfície (111) e C1 em superfície (100). Para simular o potencial aplicado ao eletrodo, campos elétricos externos de sinal positivo e perpendiculares à superfície dos clusters foram aplicados. Alterações nos comprimentos e ângulos de ligações do ânion adsorvido, bem como em seus valores de momento dipolar foram observados. Os espectros de infravermelho dos sistemas ânion-clusters foram calculados e os valores para a taxa de variação Stark (Δstark) do modo δs CH3 foram comparados com o valor experimental. Tanto para o ânion livre quanto para os sistemas onde o ânion se encontra adsorvido, verificou-se que os valores de Δstark assumiam valores negativos (indicando que a frequência vibracional do modo δs CH3 diminuía com o aumento da intensidade do campo externo), ao contrário do valor experimental, positivo (frequência do modo δs CH3 aumenta com o aumento do potencial). Apenas com a adição de moléculas de água aos sistemas estudados, de modo a simular o solvente aquoso, é que os valores de Δstark passaram a assumir um valor positivo. Essa comparação revelou a importância da presença de moléculas de água na simulação de um sistema eletroquímico e motivou uma análise pormenorizada dos orbitais de fronteira envolvidos nesse processo. Verificou-se que a interação dipolo-dipolo entre as moléculas de água e o ânion adsorvido é o responsável pelo efeito Stark, enquanto as interações eletrostáticas entre várias moléculas do ânion adsorvidas afetam a intensidade da banda de absorção do modo δs CH3 nos espectros calculados. Nas superfícies (100), a ação conjunta do campo externo e das moléculas de água, levam a molécula do ânion a adotar geometrias de adsorção mais inclinadas em relação aos sistemas sem as moléculas de água, indicando que este pode ser um fator importante para explicar a maior reatividade do ânion sobre esse tipo de superfície.
Radovic, Zorana. "Étude du comportement électrochimique du monoxyde de carbone chimisorbé sur les électrodes platine(hkl) et étude de la déposition sous-nernstienne de l'argent et du cuivre sur l'électrode platine(111)." Sherbrooke : Université de Sherbrooke, 2001.
Знайти повний текст джерелаWolff, Janpeter. "Lokale Kontrolle der Musterbildung bei der CO-Oxidation auf einer Pt(110)-Oberfläche." [S.l. : s.n.], 2002. http://www.diss.fu-berlin.de/2003/13/index.html.
Повний текст джерелаZAMAKCHARI, MOHAMED AZZEDDINE. "Etude des surfaces monocristallines de platine ptn(111)x(100) en vue de l'oxydation electrocatalytique du methanol en milieu acide." Paris 6, 1993. http://www.theses.fr/1993PA066280.
Повний текст джерелаBocquet, Marie-Laure. "Interpretation d'images obtenues par microscopie à effet tunnel (STM) de petites molécules isolées, adsorbées sur une surface 111 de platine." Lyon, École normale supérieure (sciences), 1996. http://www.theses.fr/1996ENSL0021.
Повний текст джерелаRADOSAVKIC, DENIS. "Etude de la structure atomique et electronique de surfaces (111) mixtes platine-palladium et effet de la chimisorption du monoxyde de carbone." Paris 11, 1998. http://www.theses.fr/1998PA112040.
Повний текст джерелаCroci, Mirko. "Chimisorption et diffusion de surface du monoxyde de carbone et chimisorption du monoxyde d'azote sur le platine (111) : étude par jet d'hélium thermique /." [S.l.] : [s.n.], 1992. http://library.epfl.ch/theses/?display=detail&nr=1100.
Повний текст джерелаFleming, Thomas P. "Medium energy ion scattering investigation of the structures formed by deposition of sub-monolayer platinum group metals on the copper(110) surface." Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/9329.
Повний текст джерелаFernandes, Gomes Janaina. "Etude de l'adsorption et électro-oxydation de l'éthanol sur électrodes de platine par spectroscopie de génération de la fréquence somme." Paris 11, 2007. http://www.theses.fr/2007PA112222.
Повний текст джерелаThe possible application of ethanol as a fuel for direct alcohol fuel cells continues to motivate research on the mechanisms of electro-oxidation of ethanol. In this work, the ethanol-platinum interface in acidic medium is investigated using infrared-visible SFG spectroscopy in order to document the intermediates present during the electro-oxidation of ethanol. New evidences of adsorbed intermediates of ethanol oxidation on platinum, never before observed with conventional IR spectroscopy, are reported. Our results show that a secondary ethanol derivative, previously suggested, but never before unambiguously documented, and mono and bidentate acetate, eta2-acetaldehyde, acetyl and a molecular acetic acid derivative are active intermediates of ethanol oxidation in acidic medium. In addition, we report new evidences for the presence of an ethoxy intermediate. The results obtained here also confirm the presence of previously observed ethanol oxidation intermediates: adsorbed CO and a tertiary ethanol derivative. Moreover, we explored the effects of the atomic surface structure of the electrode, alcohol concentration and electrode potential on the mechanism of the adsorption and electro-oxidation of ethanol on platinum. These effects are analyzed through the vibrational spectra of interfacial adsorbed intermediates. Comparison with the adsorption of other simple reactants (methanol, acetaldehyde and acetic acid) in acid medium indicate that even at low potential the platinum surface is highly reactive, producing similar intermediates for all reactants
Barolo, Andrea. "Studio di catalizzatori a base di film sottili di ossidi metallici di transizione su substrato metallico monocristallino." Doctoral thesis, Università degli studi di Padova, 2011. http://hdl.handle.net/11577/3427523.
Повний текст джерелаQuesto lavoro discute in proposito di film sottili di ossidi di metalli di transizione su substrato metallico cristallino in riferimento alla loro morfologia e reattività verso i gas. In particolare i sistemi analizzati sono CoO su Pd(100), SnO su Pt(110) and NiO su Pd(100).
Behafarid, Farzad. "Structure, stability, vibrational, thermodynamic, and catalytic properties of metal nanostructures: size, shape, support, and adsorbate effects." Doctoral diss., University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5121.
Повний текст джерелаPh.D.
Doctorate
Physics
Sciences
Physics
Po-Chun, Kuo, and 郭博駿. "Platinum Formation on Si(111)-7x7 Surface." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/4z2e4r.
Повний текст джерела國立中興大學
物理學系所
103
The Formation of metal silicide has attracted much attention because of its low resistivity and ohmic contact in semiconductor devices. As semiconductor device get smaller, the size effect becomes more and more important. The effect of size variation in nanoscale has also led to various physical in materials. In this work, the effect of deposited time on the structure and electronic property of platinum atoms deposited on silicon (111) surface are investigated by thermal evaporation .UHV-STM was used to check the surface morphology, the results show that the platinum atoms is self-assembled as a atomic chain with irregular arrangement the results show that on the surface. In the following, the sample was annealed at high temperature, low evaporation amount of the sample rearrange to the irregular atomic long-chain structure with [1 ̅1 ̅2] direction, and which the high amount of sample deposition will form a large island structure covers the surface. We infer that the difference between the two results, is caused by different deposited amount, the attraction between the platinum atoms and the substrate surface are affected. Finally, by use STS measurements, measuring the dI / dV curve, and to explore the relationship between the energy gap and the surface structure. The original 7 × 7 reconstructed surface energy gap of 1.17eV, disorder region is 0.97eV, and long chain structure significantly improves band gap becomes 1.68eV, and a large island structure is reduced to 1.04eV.
Tu, Hsun-Ta, and 杜訓達. "Dynamical Investigation of Platinum Atoms on Si(111)-7x7 surface." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/35123511389318567329.
Повний текст джерела國立中興大學
物理學系所
97
The adsorption and the dynamics of platinum atoms on the Si(111)-7x7 surface were studied by using a ultra high vacuum scanning tunneling microscope .It covered high coverage and low coverage experiments . In low coverage experiment ,it covered room temperature and high temperature experiments . We conferred the adsorption site of single platinum atom and inferred the hopping path of single platinum atom by using profile to analyze in room temperature experiment. We took down the time of single platinum stay in half unit cells to get the activation energy and pre-ponential factor for the platinum atoms crossing the cell boundary by Arrhenius plot. The activation energy are Ea(F→U)= 0.77±0.09eV and Ea(U→F)= 0.62±0.04eV,respectively. The pre-ponential factor are Ro(F→U)=109.85±2.73Hz and Ro(U→F)=108.77±0.54Hz,respectively. When the temperature increase to 350K,platinum atoms and silicon surface found to form a new adsorption site. When the temperature up to 360K,single platinum atom hopping could not be found any more and only the new adoption site. In high coverage experiment, we found the island structure of platinum atoms and silicon atoms. The structure were Pt silicide island(6.28x6.28).
Yang, Chou-Min, and 楊朝閔. "Direct Observation of Single Platinum Atomson Si(111)-7x7 Surface." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/46947098141122771541.
Повний текст джерела中興大學
物理學系所
95
The dynamics and the adsorption of single platinum atoms on Si(111) - 7x7 were studied by a variable temperature ultrahigh vacuum scanning tunneling microscope. The thesis divides parts: room temperature(RT) study and high Temperature(HT) study. (1)RT experiment: we observed the dynamics and the adsorption of single platinum atoms at room temperature and use profile to analyze the interaction between single platinum atoms, corner adatoms, rest atoms and center atoms. We proposed the hopping paths for platinum atoms hopping within a half unit cell, compared with silver atoms.[7] (2)HT experiment: Activation energy and pre-exponential factor for platinum atoms crossing the cell boundary were estimated by Arrhenius plot. They are 1.08±0.12eV,1015.26±1.87Hz for platinum atoms jumping out of faulted half unit cells(FHUCs); and,0.61±0.08eV,108.79±1.18Hz for platinum atoms jumping out of unfaulted half unit cells(UFHUCs) respectively. Because Ea(F->uF) is bigger than Ea(UF->F) ,the time platinum atoms staying in FHUCs should be longer than in UFHUCs. When the temperature increase to 332K, platinum atoms and silicon found to form a new stable adsorption pieces. They looked like clusters. The formation of new stable site could be Pt2Si or PtSi[2]. At temperature up to 340K, only new adsorption pieces were found on surfaces.
Hoheisel, Martin. "Oxygen and CO on the Pt3Sn(111) and Pt3Sn(110) surfaces." Doctoral thesis, 2002. https://repositorium.ub.uni-osnabrueck.de/handle/urn:nbn:de:gbv:700-2002111520.
Повний текст джерела"Hyperchanneling of low energy ions on the platinum(111) and gold(110) surfaces and ion scattering spectrometry of ferroelectric lithium tantalate." 2002. http://library.cuhk.edu.hk/record=b6073461.
Повний текст джерелаThesis (Ph.D.)--Chinese University of Hong Kong, 2002.
Includes bibliographical references.
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Mode of access: World Wide Web.
Abstracts in English and Chinese.
Kim, Yong-ju. "The growth of epitaxial iron oxides on platinum (111) as studied by x-ray photoelectron diffraction, scanning tunneling microscopy, and low energy electron diffraction." Thesis, 1995. http://hdl.handle.net/10125/9524.
Повний текст джерелаCummins, Kyle. "Interfacial Properties of Ultrathin- Film Metal Electrodes: Studies by Combined Electron Spectroscopy and Electrochemistry." Thesis, 2012. http://hdl.handle.net/1969.1/ETD-TAMU-2012-05-11199.
Повний текст джерелаAulická, Marie. "Modelové katalyzátory na bázi oxidu ceru." Doctoral thesis, 2016. http://www.nusl.cz/ntk/nusl-352075.
Повний текст джерела