Properties of Erbium (Er)

Erbium is a chemical element with the symbol (Er) and atomic number 68. It is part of the lanthanide series, a group of rare-earth elements. Erbium is a silvery-white, soft metal that is relatively stable in air but reacts slowly with water and readily forms compounds with nonmetals.

The following table provides a comprehensive list of erbium (Er) properties in both SI and US customary/Imperial units at normal temperature and pressure (NTP).

Click on the icon to switch between Metric and Imperial units.

Table of Erbium Properties
Physical Properties
Metric
Crystal StructureHexagonal close-packed (hcp)
Atomic Number68
Molar Mass167.259 g/mol
Density9066 kg/m3
Mechanical PropertiesMetric
Young’s Modulus (E)69.9 GPa
Shear Modulus (G)28.3 GPa
Bulk Modulus (K)44.4 GPa
Poisson’s Ratio (ν)0.237
Thermal PropertiesMetric
Melting Point1529 °C
Boiling Point2868 °C
Thermal Conductivity (27°C)14.5 W/m·K
Specific Heat Capacity (Cp) (25°C)168 J/kg·K
Coefficient of Thermal Expansion (αL) (25°C)1.22×10-5 1/°C
Electrical PropertiesMetric
Electrical Resistivity8.6×10-5 Ω·cm

Unless stated otherwise, all values are taken at room temperature (approximately 20°C or 68°F) and 1 atm pressure. (1 atm = 101,325 Pa)

References: 1) Cardarelli, François. Materials Handbook: A Concise Desktop Reference. Switzerland: Springer International Publishing, 2018. 2) CRC Handbook of Chemistry and Physics, 97th Edition. United Kingdom: CRC Press, 2016-2017. 3) A.M. Howatson, P.G. Lun, J.D. Todd, P.D. Engineering Tables and Data. United Kingdom: University of Oxford, Department of Engineering Science, 2009.