Magnesium Fluoride MgF<sub>2</sub> Crystal,  MSE Supplies

Magnesium Fluoride MgF2 Crystal

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Magnesium fluoride, MgF2, crystals have been widely used as windows, lenses, and prisms for wavelength from 110 nm to 7.5 um. MgF2 crystal is the most suitable material for ArF excimer lasers used in pulsed laser deposition techniques. For its excellent ulta-violet transmittance at 193nm, MgF2 crystal is effective as an optical polarizing element.  MgF2 crystal substrates are also used for thin film growth. 

MSE Supplies offers the following choices:

  • Customized crystal growth and machining
  • High quality MgF2 blank crystal materials in discs, plates, rods, customized for customers
  • High quality MgF2 VUV windows for ArF Excimer Laser
  • Customized MgF2 optics for IR and VUV applications
  • MgF2 viewport windows for Infrared thermography from 8 um to 14 um.


  • maximum diameter: 170 mm, can custom to 10 x 10 mm, 20 x 20 mm, 30 x30 mm, 40x40m
  • Clear aperture: 85%
  • Surface flatness: λ/4 at 633 nm
  • Typical Surface quality: 60/40

Optical Properties

Transmission Range

110 nm to 7.5 um


>90% at 193 nm to 6 um

Refractive Index

No=1.37608; Ne=1.38771 (at 0.7um)

Reflection Loss

5.2% at 0.6 um (both surfaces)

Residual Radiation Peak

20 nm

Absorption Coefficient

0.04 cm-1 at 2.7 um


2.3 x 10-6 /parallel c-axis

1.7 x 10-6 /perpendicular c-axis

Physical Properties


3.18 g/cm3

Melting Point


Thermal Conductivity

0.3 Wm-1K-1 at 300K

Thermal Expansion

13.7 x 10-6 /K @ parallel c-axis

8.9 x 10-6 /K @ perpendicular c-axis

Knoop Hardness

415 with 100g indenter (kg/mm2)

Specific Heat Capacity

1003 J/(kg.K)

Dielectric Constant

1.87 at 1MHz parallel c-axis

1.45 at 1MHz perpendicular c-axis

Youngs Modulus (E)

138.5 GPa

Shear Modulus (G)

54.66 GPa

Bulk Modulus (K)

101.32 GPa

Elastic Coefficient

C11=164; C12=53; C44=33.7

C13=63; C66=96

Apparent Elastic Limit

49.6 MPa (7200 psi)

Poisson Ratio


Chemical Properties


0.0002 g/ 100g water at 20°C

Molecular Weight

62.32 g/mol


Tetragonal Crystal

Cleavage Plane