Zirconium

Zirconium • Transition Metal

Primary XPS region: Zr3d
Overlapping regions: B1s
Binding energies of common chemical states:

Chemical state	Binding energy Zr3d_5/2
Zr metal	178.9 eV
Zr sub-oxides	179-180.5 eV
ZrO	182.3 eV
Zr(IV) silicate₂	182.7 eV

Experimental information

N/A

Interpretation of XPS spectra

Zr3d region has well-resolved spin-orbit components (Δ_metal=2.4eV).
- Spin-orbit splitting changes with chemical state.
Zr3d peaks for Zr metal have an asymmetric peak shape.
- The same is true for conducting zirconium compounds, such as ZrB₂.

General comments

Zr is a reactive metal and usually found as oxide, ZrO₂.
The oxide is reduced to sub-oxides by argon ion bombardment.
Commonly seen as minor components in Hf-containing compounds.

About this element

Symbol: Zr
Date of discovery: 1789
Name origin: Arabic zarkûn
Appearance: silvery white
Discoverer: Martin Heinrich Klaproth
Obtained from: zircon

Melting point: 1852 K
Boiling point: 4490 K
Density[kg/m³]: 6.52
Molar volume: 14.02 × 10^-6 m³/mol
Protons/Electrons: 40
Neutrons: 51
Shell structure: 2,8,18,10,2
Electron configuration: [Kr]4d25s2
Oxidation state: 4
Crystal structure: hexagonal

At elevated temperatures, this silvery white metal can ignite spontaneously in air. It is found in S-type stars and has been identified in our own sun, as well. Zirconium is used in flash bulbs for photography, explosive primers, and lamp filaments. It is also used as the main ingredient of cubic zirconium stones. Similar in appearance to diamonds, cubic zirconium stones are sold as an affordable alternative to the more precious diamond. Although zirconium does not play a biological role, human tissue does assimilate the element, making it suitable for some artificial joints and limbs.