Sodium • Alkali Metal

Primary XPS region: Na1s
Overlapping regions: Ti LMM
Binding energies of common chemical states:

Chemical stateBinding energy Na1s
Sodium compounds1,071–1,071.5 eV

 

Experimental information

  • In the presence of a high concentration of titanium, acquire Na2s or Na KLL peak as well as (or instead of) the Na1s peak.

 

Interpretation of XPS spectra

  • There are only a small range of chemical shifts ~0.5eV and determination of chemical state may require use of corresponding regions to infer chemical state.
  • Na1s peak is accompanied by strong Auger peak at ~497eV.
    • If sodium is buried (under carbon, for example), Na Auger peak may be observed even if Na1s is not (due to difference in electron kinetic energy).
    • Similarly, Na2s (high kinetic energy) may be observed even if Na1s is not.
  • Potential sodium Auger overlap with O1s (typically ~536eV).

 

O1s Region NaHCO3

     

  • The Na1s peak is strongly overlapped by Ti LMM Auger peaks.
    • This overlap is particularly important when analyzing apatite formation on the bioactive alloy, Ti-6Al-4V, for example.
    • To quantify the Na1s peak in these situations, it is necessary to peak fit the overlapping XPS and Auger peaks.

 

Sodium • Alkali Metal
Ti LMM Na1s Region TiO2 NaHCO3 Sample

 

General comments

  • Na is a highly reactive metal and usually only sodium compounds will be observed in XPS spectra.
  • The presence of sodium, especially with the presence of chlorine and an intense hydrocarbon C1s peak, can indicate contamination from manual handling, without the use of gloves.
  • Glass materials may exhibit increased amount of sodium at the surface due to diffusion processes.
    • Exposure of glass to higher energy electrons (few hundred eV or higher) may cause diffusion of Na into bulk or across the surface out of the irradiated area.

 

 

Element Crystal bcc

About this element

Symbol: Na
Date of discovery: 1807
Name origin: English soda
Appearance: silvery
Discoverer: Sir Humphry Davy
Obtained from: table salts

Melting point: 370.87 K
Boiling point: 1156 K
Density[kg/m3]: 968
Molar volume: 23.78 × 10-6 m3/mol
Protons/Electrons: 11
Neutrons: 12
Shell structure: 2,8,1
Electron configuration: [Ne]3s1
Oxidation state: 1
Crystal structure: cubic body centered

This soft, waxy, silvery, reactive metal was isolated in 1807 by Sir Humphry Davy, though it had been recognized in compounds long before. A compound of sodium was used as a headache remedy in Medieval Europe. The most common compound of sodium is sodium chloride, or table salt. Another compound is used in soap in combination with fatty acids. Sodium is the most abundant of all alkali metals and the fourth most abundant element overall, making up 2.6% of the Earth’s crust. It is also relatively abundant in stars. Sodium, being highly reactive, burns with a yellow flame, oxidizes in air, and will spontaneously ignite in water. Sodium ions are necessary in the depolarization of cells, vital to the neural system of most animals, including humans.

 


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.