Magnesium Fluoride vs. Soda-lime Glass

Magnesium fluoride belongs to the non-glass optical ceramics classification, while soda-lime glass belongs to the glass and glass-ceramics. There are 13 material properties with values for both materials. Properties with values for just one material (8, in this case) are not shown.

For each property being compared, the top bar is magnesium fluoride and the bottom bar is soda-lime glass.

Magnesium Fluoride (MgF₂) Optical Material Soda-Lime (Float) Glass

Metric UnitsUS Customary Units

Mechanical Properties

Elastic (Young's, Tensile) Modulus, GPa		130
Elastic (Young's, Tensile) Modulus, GPa		70 to 71

Poisson's Ratio		0.27
Poisson's Ratio		0.23

Shear Modulus, GPa		76
Shear Modulus, GPa		29

Thermal Properties

Specific Heat Capacity, J/kg-K		980
Specific Heat Capacity, J/kg-K		720 to 800

Thermal Conductivity, W/m-K		28
Thermal Conductivity, W/m-K		1.0 to 1.1

Thermal Expansion, µm/m-K		11
Thermal Expansion, µm/m-K		8.8 to 9.0

Electrical Properties

Dielectric Constant (Relative Permittivity) At 1 MHz		5.2
Dielectric Constant (Relative Permittivity) At 1 MHz		7.3 to 7.4

Otherwise Unclassified Properties

Density, g/cm³		3.2
Density, g/cm³		2.4

Light Transmission Range, µm		0.12 to 7.0
Light Transmission Range, µm		0.35 to 2.5

Refractive Index		1.4
Refractive Index		1.5

Common Calculations

Stiffness to Weight: Axial, points		22
Stiffness to Weight: Axial, points		16

Stiffness to Weight: Bending, points		52
Stiffness to Weight: Bending, points		56

Thermal Diffusivity, mm²/s		8.8
Thermal Diffusivity, mm²/s		0.51 to 0.6