MgF2
also Irtran-1
MgF2 is a hard, birefringent magnesium fluoride crystal, supplied as UV-grade single crystal, hot-pressed polycrystal (Irtran-1) and evaporation pellets, that transmits 0.12–8 µm.
Reference datasheet — MgF2 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the SC-UV condition
MgF2 tempers and conditions
MgF2 is supplied in 3 conditions, soft to hard. SC-UV is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Coating/evaporation grade | Use the 99.9–99.99 % granules or crystal pieces as feedstock for e-beam or resistive evaporation of low-index AR coatings; only purity, water/oxygen content and film stress matter, not bulk mechanicals. | 40 | 0 | 400 HV | 16 W/m·K | |
Hot-pressed polycrystalline | Pick the hot-pressed polycrystal for large-aperture, high-strength IR windows and domes; scatter and absorption above 3–5 µm exceed single crystal and the UV range is unusable. | 560 HV | 15 W/m·K | |||
SC-UVDefault VUV/UV-grade single crystal | Choose the Bridgman/Stockbarger-grown crystal for deep-UV windows, excimer-laser optics, polarising prisms and space VUV instruments; cut oriented to the optic axis to control birefringence. | 21 W/m·K |
What is MgF2?
MgF2 is a hard, birefringent magnesium fluoride crystal, supplied as UV-grade single crystal, hot-pressed polycrystal (Irtran-1) and evaporation pellets, that transmits 0.12–8 µm. It is the standard low-index material for antireflection coatings and deep-UV windows, with density 3.18 g/cm³, 138.5 GPa elastic modulus and 21 W/m·K thermal conductivity. Service temperature reaches 800 °C, but the crystal is birefringent, cleaves on (110) and can be shaped only with diamond tooling (machinability 25). CaF2 is the usual isotropic substitute when birefringence cannot be tolerated. MgF2 has a density of 3.18 g/cm³ (0.115 lb/in³), heavier than 58% of glass grades. It melts at 1,255°C (2,291 °F). The elastic modulus is 138.5 GPa (20.1 Msi).
What is MgF2 used for?
- AR coatings
- UV windows
- waveplates
- excimer laser optics
Advantages
- Stiff — 138.5 GPa (20.1 Msi), better than 90% of glass grades
- Conducts heat well — 21 W/m·K (12.1 BTU/hr·ft·°F), better than 86% of glass grades
- High service temperature — 800°C (1,472 °F), better than 81% of glass grades
- Tough — resists crack growth — 0.9 MPa·√m (0.819 ksi·√in), better than 79% of glass grades
MgF2 properties
Typical room-temperature values for MgF2-SC-UV; bars are the position among glass grades.
Physical5
MgF2 has a density of 3.18 g/cm³ (0.115 lb/in³), heavier than 58% of glass grades. It melts at 1,255°C (2,291 °F).
Mechanical10
The elastic modulus is 138.5 GPa (20.1 Msi).
Thermal5
MgF2 is rated for continuous service to 800°C (1,472 °F). It conducts heat at 21 W/m·K (12.1 BTU/hr·ft·°F), better than 86% of glass grades. Thermal expansion is 11.3 µm/m·K (6.28 µin/in·°F).
Electrical3
MgF2 has an electrical resistivity of 1×10¹² Ω·m.
Chemical & Environmental2
Corrosion resistance is very good (70/100), worse than 58% of glass grades.
Manufacturability2
MgF2's machinability is poor (25/100, better than 63% of glass grades).
Common Calculations2
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the glass family
Yield strength against density for every glass grade FabDigit runs. MgF2 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with MgF2
Is MgF2 easy to machine?
Grind, saw and cut with diamond tooling only, using light feeds; watch the (110) cleavage plane and keep the birefringent axis orientation under control. Avoid long immersion in water-based coolant.
Can MgF2 be welded?
Not weldable; seal into metal seats with low-stress compliant clamping, epoxy, or low-temperature solder.
Can MgF2 be formed, bent or molded?
Single crystals are grown by the Bridgman crucible-lowering method under a fluorinating atmosphere; polycrystalline parts are vacuum hot-pressed at 900–1000 °C. No cold plastic working is possible.
MgF2 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Mgstoichiometric MgF2 | 38.5 – 39.5 | 39 |
| Ooxygen/oxide impurity, key for VUV transmission | ≤ 0.05 | 0.01 |
| Fetransition-metal impurity limit for UV grade | ≤ 0 | 3×10⁻⁴ |
| F | ≥ 60.5 (balance) |
What surface finishes work on MgF2?
Conventional lapping and polishing reach sub-nanometre RMS roughness. Finished optics are normally coated with MgF2 or multilayer dielectric AR stacks; clean with anhydrous solvents and avoid strong acids and hot, humid conditions.
Equivalent designations
Standards and trade names that resolve to MgF2 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- Trade names
- Irtran-1
How much does MgF2 cost?
MgF2 is a high-cost glass ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
MgF2 — frequently asked
What is MgF2 used for?
MgF2 is typically used for AR coatings, UV windows, waveplates and excimer laser optics. In short: standard low-index AR material; deep-UV to mid-IR transmission; birefringent, needs axis control.
Is MgF2 easy to machine?
Not especially — machinability is rated poor (25/100, better than 63% of glass grades). Grind, saw and cut with diamond tooling only, using light feeds; watch the (110) cleavage plane and keep the birefringent axis orientation under control. Avoid long immersion in water-based coolant.
Can MgF2 be welded?
Not weldable; seal into metal seats with low-stress compliant clamping, epoxy, or low-temperature solder.
What surface finishes work on MgF2?
Conventional lapping and polishing reach sub-nanometre RMS roughness. Finished optics are normally coated with MgF2 or multilayer dielectric AR stacks; clean with anhydrous solvents and avoid strong acids and hot, humid conditions.
Can MgF2 be formed, bent or molded?
Single crystals are grown by the Bridgman crucible-lowering method under a fluorinating atmosphere; polycrystalline parts are vacuum hot-pressed at 900–1000 °C. No cold plastic working is possible.
What is the maximum service temperature of MgF2?
MgF2 is rated for continuous use to about 800°C (1,472 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does MgF2 cost?
MgF2 is a high-cost glass ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- Magnesium Fluoride (MgF2) Optical Material Data — Crystran Ltd (2023)
- MgF2 Single Crystal Datasheet — Korth Kristalle GmbH (2022)
- Handbook of Optical Constants of Solids (MgF2, Dodge dispersion) — Academic Press (1985)
- CRC Handbook of Chemistry and Physics — CRC Press (2020)
- Infrared window materials: Irtran-1 hot-pressed MgF2 properties — ASM/optical materials compilations (2010)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.