Oxygen • Non-Metals

Primary XPS region: O1s
Overlapping regions: Na KLL, Sb3d, Pd3p, V2p
Binding energies of common chemical states:

Chemical stateBinding energy O1s
Metal oxides529–530 eV
Metal carbonates531.5–532 eV
Al2O3 (alumina)531.1 eV
SiO2532.9 eV
Organic C=O531.5–532 eV
Organic C-O~533 eV
O-Fx~535 eV

Charge referenced to adventitious C1s peak at 284.8eV.

 

Experimental information
  • The O1s region may be overlapped by peaks from antimony, palladium, or vanadium.
    • In the case of antimony, collect the full Sb3d / O1s region (525-550eV), making sure both Sb3d5/2 and Sb3d3/2 components are acquired.
    • In the case of palladium, collect the full Pd3p / O1s region (525–580eV), making sure both Pd3p3/2 and Pd3p1/2 components are acquired.
  • During sputter depth profiling, it is preferable to collect data from the O1s region first in each data collection cycle.

 

Interpretation of XPS spectra
  • Interpretation of O1s spectra is not straightforward.
    • Apart from metal oxides, the O1s binding energy of many compounds and species falls within a very narrow range.
    • O1s peaks tend to be broad, with multiple overlapping components.
      • Components due to water and/or organic contamination overlap directly with SiO2, for example.
      • Organic contamination also makes it difficult to discern carbonates in the O1s region.
      • It is typically not possible to uniquely peak fit these overlapping components.
      • The user normally has to impose peak fitting constraints, e.g. all overlapping components have the same (or similar) full width half-maximum.
O1s Spectrum Received Copper Carbonate Dihydroxide
  • The peak fitting challenges mentioned above make it difficult to accurately quantify the oxygen chemical states.
    • In the copper (II) carbonate dihydroxide example shown above, the quantification of the carbonate versus hydroxide changes significantly according to peak fitting procedure.
  • Metal oxides appear at a significantly different binding energy compared to most other oxygen species.
    • They also tend to have narrower O1s peaks compared to other species, e.g. carbonates.
    • It is often possible to directly observe the relative full width half-maximum of each component in the O1s spectrum.
Oxygen • Non-Metals
O1s Spectrum Received Lanthanum Strontium Cobaltite
  • Sodium Auger peak (Na KLL) sometimes observed ~535eV.
    • Peak is much broader than O1s XPS components.
O1s Region NaHCO3
  • If a particularly large chemical shift is observed, it could be due to O-Fx bonding.
  • A big loss feature is often observed to higher binding energy of the main O1s peak.
O1s Spectrum Loss Features Ar Sputtered Al2O3
General comments
  • Oxygen will always be present on samples exposed to the atmosphere, either due to adventitious contamination, oxidation, or water.
  • Can use O1s peak position and plasmon to measure band gaps for certain materials [1].

 

References
  • [1] H. Nohira et al., Journal of Non-Crystalline Solids 303 (2002) 83–87.

 

About this element

Element Crystal Mono

Symbol: O
Date of discovery: 1774
Name origin: Greek oxus and gennan
Appearance: colorless
Discoverer: Joseph Priestley/Carl Scheele
Obtained from: liquid air

Melting point: 54 K
Boiling point: 90 K
Density[kg/m3]: 1.429
Molar volume: 17.36 × 10-6 m3/mol
Protons/Electrons: 8
Neutrons: 8
Shell structure: 2,6
Electron configuration: [He]2s22p4
Oxidation state: -2,-1
Crystal structure: monoclinic

Oxygen, the "elixir of life", was discovered by Joseph Priestly and Carl Wilhem Scheele independently of each other in the 1770’s. Oxygen is critical for life on Earth, produced by plants during photosynthesis and necessary for aerobic respiration in animals. Accounting for one-fifth of the earth’s atmosphere, oxygen combines with most elements and is a component of thousands of organic compounds. Oxygen is colorless, odorless, and tasteless in its gaseous form, and condenses to pale blue liquid and solid forms. Oxygen is a highly reactive element that promotes rapid combustion and is often used in industrial applications.

 


Products

Nexsa G2 XPS

  • Micro-focus X-ray sources
  • Unique multi-technique options
  • Dual-mode ion source for monoatomic & cluster ion depth profiling
Style Sheet for Instrument Cards Original

K-Alpha XPS

  • High resolution XPS
  • Fast, efficient, automated workflow
  • Ion source for depth profiling

ESCALAB Xi+ XPS

  • High spectral resolution
  • Multi-technique surface analysis
  • Extensive sample preparation and expansion options

Contact us

Style Sheet for Global Design System
Style Sheet for Komodo Tabs
Style Sheet to change H3 to p with em-h3-header class
Style Sheet to change H2 style to p with em-h2-header class
Style Sheet for Products Table Specifications
Style Sheet for Global Design System
Style Sheet for Komodo Tabs
Style Sheet to change H3 to p with em-h3-header class
Style Sheet to change H2 style to p with em-h2-header class
Style Sheet for Products Table Specifications
Fix for left nav
Style Sheet for Support and Service footer
Style Sheet for Fonts
Style Sheet for Cards

Electron microscopy services for
the materials science

To ensure optimal system performance, we provide you access to a world-class network of field service experts, technical support, and certified spare parts.