Modifying the STM tip for the ' ultimate ' imaging of the Si(111)-7×7 surface and metal-supported molecules.
Chimia (Aarau)
; 66(1-2): 31-7, 2012.
Article
em En
| MEDLINE
| ID: mdl-22546188
ABSTRACT
We report on high-resolution STM measurements with modified probe tips. First, both the rest atoms and adatoms of a Si(111)-7×7 surface are observed simultaneously. The visibility of rest atoms is dependent upon the sample bias voltage (less than -0.7 V) and is enhanced by sharpening the tip, which is rationalized by first-principles calculations. Second, a tip with a perylene molecule adsorbed at its apex is used to discriminate the molecular states and the metal states of the underlying Ag(110) surface, which is attributable to a mismatch between the energy levels of the functionalized tip and the adsorbates on silver. Lastly, high-resolution images of iron phthalocyanine (FePc) and zinc phthalocyanine (ZnPc) molecules on Au(111) are obtained by using an O(2)-terminated tip, and the images reveal rich intramolecular features arising from molecular orbitals that are not observed when using clean metallic tips.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Compostos Organometálicos
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Oxigênio
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Silício
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Prata
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Compostos Ferrosos
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Indóis
Idioma:
En
Revista:
Chimia (Aarau)
Ano de publicação:
2012
Tipo de documento:
Article