Aluminium • Other Metal

Primary XPS region: Al2p
Overlapping regions: Pt4f, Cu3p
Binding energies of common chemical states:

Chemical stateBinding energy Al2p
Al metal72.6 eV
Aluminosilicate74.4 eV
Al oxide74.6 eV
Al oxide on Al foil75.6 eV

Oxide/foil referenced to Al2p metal peak.
Silicate and alumina referenced to adventitious C1s peak at 284.8eV.

 

Experimental Information

  • In the presence of high platinum or copper concentrations, acquire Al2s as well as (or instead of) Al2p peak.

 

Interpretation of XPS Spectra

  • Aluminium oxide is an insulating material and the oxide peak position may vary with the thickness of the film.
    • The relative intensities of the oxide and metallic peaks will also change with oxide thickness.
      • This effect allows XPS to measure the thickness of Al oxide films.
  • Al2p peak has closely-spaced spin-orbit components (Δmetal=0.44eV).
    • Splitting only observed for Al metal and under typical experimental conditions, manifests as asymmetry in peak rather than outright splitting.
    • Splitting may be ignored for Al2p peaks from aluminium compounds, such as Al oxide.
  • Metallic Al2p peak is ideally fit with asymmetric peak shapes.
    • Compounds, such as Al oxide, have symmetric Al2p peaks.

 

Element-Aluminum-Xpsspectra
element_aluminium
  • Aluminium metal exhibits energy loss features with a significant intensity.
    • These features can overlap/obscure XPS peaks to higher binding energy, e.g., Si2p and Si2s peaks.

 

aluminium-xpsspectra-450x300

General comments
  • Aluminium is a highly reactive metal, so always have a surface oxide present.
    • The thickness of the oxide film may vary depending upon any previous cleaning treatment.
  • Aluminium oxide may be hydrated with the presence of hydroxide species.
    • These may react with atmospheric CO2 to form surface carbonates.
  • After Ar+ sputtering, the reactive surface may adsorb oxygen and reform oxides.

 

About This Element
element-crystal-fcc-resized-120x80

Symbol: Al
Date of discovery: 1825
Name origin: Latin alumen
Appearance: silver
Discoverer: Hans Christian Ørsted
Obtained from: bauxite

Melting point: 933.52 K
Boiling point: 2740.15 K
Density[kg/m3]: 2700
Molar volume: 10.00 × 10-6 m3/mol
Protons/Electrons: 13
Neutrons: 14
Shell structure: 2,8,3
Electron configuration: [Ne]3s23p1
Oxidation state: 3
Crystal structure: cubic face centered

While ancient civilizations used aluminium salts for dyeing mordants and astringents, it wasn’t until 1825 that H. Ørsted isolated aluminium. The biggest breakthrough came in 1886, when C. Hall developed an inexpensive electrolytic process for extracting aluminium from the ore bauxite. This process is still commonly used today. Aluminium is valued for its light weight, strength, durability, and resistance to oxidation, and has propelled the use of aluminium alloys for aircraft and rockets. Evidence exists that high levels of aluminium may be toxic, although aluminium is generally considered less toxic than most heavy metals. Although the durability of aluminium is well-known, certain chemicals, such as mercury, can cause corrosion in aluminium. This is the reason why mercury thermometers are not allowed on aircrafts.

 


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.