The oxidation of Mo(100) studied by XPS and surface Raman spectroscopy: the onset of MoO2 formation and the formation of surface polymolybdate

George H. Smudde; Peter C. Stair

doi:10.1016/0039-6028(94)90253-4

The oxidation of Mo(100) studied by XPS and surface Raman spectroscopy: the onset of MoO₂ formation and the formation of surface polymolybdate

George H. Smudde, Peter C. Stair^*

^*Corresponding author for this work

Chemistry

Research output: Contribution to journal › Article › peer-review

29 Scopus citations

Abstract

Oxidation of the Mo(100) single crystal surface at 700-900 K with molecular oxygen has been studied in ultrahigh vacuum using X-ray photoelectron spectroscopy (XPS) and surface Raman spectroscopy. Whereas the onset of oxide formation was previously found to occur at oxygen coverages just over one monolayer, the nucleation of crystalline MoO₂ requires a threshold oxide thickness between 6 and 8 Å, just over one unit cell thick, as indicated by the pronounced appearance of MoO₂ features in the surface Raman spectrum. After extensive oxidation at low oxygen pressures the formation of Mo⁶⁺ was observed by XPS. Contrary to previous conclusions the Mo⁶⁺ does not appear to be due to the formation of MoO₃ but is associated with surface polymolybdate species on the oxidized surface.

Original language	English (US)
Pages (from-to)	65-72
Number of pages	8
Journal	Surface Science
Volume	317
Issue number	1-2
DOIs	https://doi.org/10.1016/0039-6028(94)90253-4
State	Published - Sep 20 1994

ASJC Scopus subject areas

Condensed Matter Physics
Surfaces and Interfaces
Surfaces, Coatings and Films
Materials Chemistry

Access to Document

10.1016/0039-6028(94)90253-4

Cite this

@article{19748af0f4aa40049e35863aec1eb5d4,

title = "The oxidation of Mo(100) studied by XPS and surface Raman spectroscopy: the onset of MoO2 formation and the formation of surface polymolybdate",

abstract = "Oxidation of the Mo(100) single crystal surface at 700-900 K with molecular oxygen has been studied in ultrahigh vacuum using X-ray photoelectron spectroscopy (XPS) and surface Raman spectroscopy. Whereas the onset of oxide formation was previously found to occur at oxygen coverages just over one monolayer, the nucleation of crystalline MoO2 requires a threshold oxide thickness between 6 and 8 {\AA}, just over one unit cell thick, as indicated by the pronounced appearance of MoO2 features in the surface Raman spectrum. After extensive oxidation at low oxygen pressures the formation of Mo6+ was observed by XPS. Contrary to previous conclusions the Mo6+ does not appear to be due to the formation of MoO3 but is associated with surface polymolybdate species on the oxidized surface.",

author = "Smudde, {George H.} and Stair, {Peter C.}",

note = "Funding Information: This material is based upon work primarily supported by the National Science Foundation under Grants No. CHE-8821781 and CHE-9305937.",

year = "1994",

month = sep,

day = "20",

doi = "10.1016/0039-6028(94)90253-4",

language = "English (US)",

volume = "317",

pages = "65--72",

journal = "Surface Science",

issn = "0039-6028",

publisher = "Elsevier",

number = "1-2",

}

TY - JOUR

T1 - The oxidation of Mo(100) studied by XPS and surface Raman spectroscopy

T2 - the onset of MoO2 formation and the formation of surface polymolybdate

AU - Smudde, George H.

AU - Stair, Peter C.

N1 - Funding Information: This material is based upon work primarily supported by the National Science Foundation under Grants No. CHE-8821781 and CHE-9305937.

PY - 1994/9/20

Y1 - 1994/9/20

N2 - Oxidation of the Mo(100) single crystal surface at 700-900 K with molecular oxygen has been studied in ultrahigh vacuum using X-ray photoelectron spectroscopy (XPS) and surface Raman spectroscopy. Whereas the onset of oxide formation was previously found to occur at oxygen coverages just over one monolayer, the nucleation of crystalline MoO2 requires a threshold oxide thickness between 6 and 8 Å, just over one unit cell thick, as indicated by the pronounced appearance of MoO2 features in the surface Raman spectrum. After extensive oxidation at low oxygen pressures the formation of Mo6+ was observed by XPS. Contrary to previous conclusions the Mo6+ does not appear to be due to the formation of MoO3 but is associated with surface polymolybdate species on the oxidized surface.

AB - Oxidation of the Mo(100) single crystal surface at 700-900 K with molecular oxygen has been studied in ultrahigh vacuum using X-ray photoelectron spectroscopy (XPS) and surface Raman spectroscopy. Whereas the onset of oxide formation was previously found to occur at oxygen coverages just over one monolayer, the nucleation of crystalline MoO2 requires a threshold oxide thickness between 6 and 8 Å, just over one unit cell thick, as indicated by the pronounced appearance of MoO2 features in the surface Raman spectrum. After extensive oxidation at low oxygen pressures the formation of Mo6+ was observed by XPS. Contrary to previous conclusions the Mo6+ does not appear to be due to the formation of MoO3 but is associated with surface polymolybdate species on the oxidized surface.

UR - http://www.scopus.com/inward/record.url?scp=0028496363&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028496363&partnerID=8YFLogxK

U2 - 10.1016/0039-6028(94)90253-4

DO - 10.1016/0039-6028(94)90253-4

M3 - Article

AN - SCOPUS:0028496363

SN - 0039-6028

VL - 317

SP - 65

EP - 72

JO - Surface Science

JF - Surface Science

IS - 1-2

ER -

The oxidation of Mo(100) studied by XPS and surface Raman spectroscopy: the onset of MoO₂ formation and the formation of surface polymolybdate

Abstract

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this