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Title: Growth of nanocrystalline MoO3 on Au(111) studied by in-situ STM

Abstract

The growth of nanocrystalline MoO{sub 3} islands on Au(111) using physical vapor deposition of Mo has been studied by scanning tunneling microscopy (STM) and low energy electron diffraction (LEED). The growth conditions affect the shape and distribution of the MoO{sub 3} nanostructures, providing a means of preparing materials with different percentages of edge sites that may have different chemical and physical properties than atoms in the interior of the nanostructures. MoO{sub 3} islands were prepared by physical vapor deposition of Mo and subsequent oxidation by NO{sub 2}exposure at temperatures between 450 K and 600 K. They exhibit a crystalline structure with a c(4x2) periodicity relative to unreconstructed Au(111). While the atomic-scale structure is identical to that of MoO{sub 3} islands prepared by chemical vapor deposition, we demonstrate that the distribution of MoO{sub 3} islands on the Au(111) surface reflects the distribution of Mo clusters prior to oxidation although the growth of MoO{sub 3} involves long-range mass transport via volatile MoO{sub 3} precursor species. The island morphology is kinetically controlled at 450 K, whereas an equilibrium shape is approached at higher preparation temperatures or after prolonged annealing at the elevated temperature. Mo deposition at or above 525 K leads to themore » formation of a Mo-Au surface alloy as indicated by the observation of embedded MoO{sub 3} islands after oxidation by NO{sub 2}. Au vacancy islands, formed when Mo and Au dealloy to produce vacancies, are observed for these growth conditions.« less

Authors:
; ; ;
Publication Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
15020077
Report Number(s):
UCRL-JRNL-203881
TRN: US200519%%161
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Journal Article
Journal Name:
Journal of Chemical Physics B
Additional Journal Information:
Journal Volume: 107; Journal Issue: 42
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALLOYS; ANNEALING; ATOMS; CHEMICAL VAPOR DEPOSITION; DEPOSITION; DISTRIBUTION; ELECTRON DIFFRACTION; MORPHOLOGY; NANOSTRUCTURES; OXIDATION; PERIODICITY; PHYSICAL PROPERTIES; PHYSICAL VAPOR DEPOSITION; PRECURSOR; SCANNING TUNNELING MICROSCOPY

Citation Formats

Biener, M M, Biener, J, Schalek, R, and Friend, C M. Growth of nanocrystalline MoO3 on Au(111) studied by in-situ STM. United States: N. p., 2004. Web.
Biener, M M, Biener, J, Schalek, R, & Friend, C M. Growth of nanocrystalline MoO3 on Au(111) studied by in-situ STM. United States.
Biener, M M, Biener, J, Schalek, R, and Friend, C M. 2004. "Growth of nanocrystalline MoO3 on Au(111) studied by in-situ STM". United States. https://www.osti.gov/servlets/purl/15020077.
@article{osti_15020077,
title = {Growth of nanocrystalline MoO3 on Au(111) studied by in-situ STM},
author = {Biener, M M and Biener, J and Schalek, R and Friend, C M},
abstractNote = {The growth of nanocrystalline MoO{sub 3} islands on Au(111) using physical vapor deposition of Mo has been studied by scanning tunneling microscopy (STM) and low energy electron diffraction (LEED). The growth conditions affect the shape and distribution of the MoO{sub 3} nanostructures, providing a means of preparing materials with different percentages of edge sites that may have different chemical and physical properties than atoms in the interior of the nanostructures. MoO{sub 3} islands were prepared by physical vapor deposition of Mo and subsequent oxidation by NO{sub 2}exposure at temperatures between 450 K and 600 K. They exhibit a crystalline structure with a c(4x2) periodicity relative to unreconstructed Au(111). While the atomic-scale structure is identical to that of MoO{sub 3} islands prepared by chemical vapor deposition, we demonstrate that the distribution of MoO{sub 3} islands on the Au(111) surface reflects the distribution of Mo clusters prior to oxidation although the growth of MoO{sub 3} involves long-range mass transport via volatile MoO{sub 3} precursor species. The island morphology is kinetically controlled at 450 K, whereas an equilibrium shape is approached at higher preparation temperatures or after prolonged annealing at the elevated temperature. Mo deposition at or above 525 K leads to the formation of a Mo-Au surface alloy as indicated by the observation of embedded MoO{sub 3} islands after oxidation by NO{sub 2}. Au vacancy islands, formed when Mo and Au dealloy to produce vacancies, are observed for these growth conditions.},
doi = {},
url = {https://www.osti.gov/biblio/15020077}, journal = {Journal of Chemical Physics B},
number = 42,
volume = 107,
place = {United States},
year = {Thu Apr 22 00:00:00 EDT 2004},
month = {Thu Apr 22 00:00:00 EDT 2004}
}