Magnesium Fluoride
MgF2

Crystal properties

Crystal Type

Rutile type structure

Transmission Range

0.11 ... 7.5 µm

Reststrahlen

20.0 µm

Density

3.177 g/cm3

Melting Point

1255 °C

Molecular Weight

62.3018

Thermal Conductivity

25.0 W/(m K) @ 20 K

0.3 W/(m K) @ 300 K

Thermal Expansion

|| C: 13.7×10–6 /

^C: 8.48×10–6 / K

Hardness (Knoop)

415.6

 

Young’s Modulus

158.55 GPa

 

Shear Modulus

54.66 GPa

 

Bulk Modulus

101.32 GPa

 

Rupture Modulu

49.0 MPa

 

Elastic Coefficient

C11 = 140.2 
C12 = 89.5

C33 = 204.7 GPa

Dielectric Constant

|| C: 4.87

^C: 5.45

Solubility in Water

< 0.0002 g / 100 g @ 0...60 °C

 

Cleavage Planes:

(110)

Standard Diameter

140 mm

Application

Scintillation material
correction part in lens systems

Remarks

radiation resistant, susceptible to thermal shock 
laser damage threshold: 27.5 GW/cm2, @ 3.8 mm, 
75 ns pulse length

List of Optical Crystals

Materials

Refractive Index

Transmission
Range (mm)

Density
(g/cm³)

Thermal Expansion  
Coefficient (10
-6/K) 

 

BK7 glass

1.5164 (588 nm)

0.330 – 2.1

2.51

7.5 

 

SF11 glass

1.78472 (588 nm)

0.370 – 2.5

4.74

6.8 

 

F2 glass

1.62004 (588 nm)

0.420 – 2.0

3.61

8.2 

 

Fused Silica

1.4858 (308 nm)

0.185 – 2.5

2.20

0.55 

 

CaF2

1.399 (5.0 mm)

 0.170 – 7.8

3.18

 18.85 

 

BaF2

1.460 (3.0 um)

 0.15 – 12.0

4.88

 18.4 

 

Sapphire

1.755 (1.0mm)

0.180 – 4.5

3.98

8.4 

 

Silicon

3.4179 (10mm)

 1.200 – 7.0

2.33

 4.15 

 

Ge

4.003 (10 mm)

 1.900 – 16

5.33

 6.1 

 

ZnSe

2.40  (10 mm)

0.630 – 18

5.27

7.8 

 

ZnS

2.2 (10mm)

0.380 –14

4.09

6.5 

 

LiF

1.39 (500 nm)

 0.150 – 5.2

2.64

37 

 

KBr

1.526 (10 mm)

 0.280 – 22

2.75

43 

 

 MgF2

no=1.3836
ne=1.3957
(405 nm)

0.130 – 7.0

7.37

a: 13.7         b: 8.48 

 

YVO4

no= 1.9500
ne=2.1554
(1.3 mm)

0.400 – 5.0

4.22

a: 4.46       b: 11.37 

 

Calcite

no=1.6557
ne= 1.4852
(633 nm)

0.210 – 2.3

2.75

a: 24.39        b: 5.68 

 

Quartz

no=1.5427
ne=1.5518
(633 nm)

0.200 – 2.3

2.65

7.07 

 

α-BBO

no=1.6749
ne= 1.5555
(532 nm)

0.190 – 3.5

3.85

a: 4.0           c: 36 

 

LiNbO3

no=2.2863
ne= 2.2027
(633 nm)

0.370 – 4.5

4.64

a: 16.7          c: 2.0