Optical and spectral properties
Transmission range in µm (minimum 10%)
0,12‐9,6
Transmission range in µm (minimum 50%)
0,12‐8,5
Refractive index @633nm
1,375 (no)

1,389 (neo)

Reflection losses in % at 1 surface
2,52 @633nm
Reflection losses, % for two surfaces
11,2 @120nm
dN/dT in 1/K
2,3 · 10-6 (parallel)

1,7 · 10-6 (perpendicular)

@400nm

Physical properties
Density in g/cm3
3,177
Melting point in °C
1255
Specific heat capacity in J/(kg · K)
1004
Thermal conductivity in W/(m · K)
21 (parallel)

33,6 (senkrecht)

@300K

Thermal expansion in 1/K
13,7 · 10-6 (parallel)

8,9 · 10-6 (perpendicular)

Dielectric constant
4,87 (parallel)

5.45 (perpendicular)

Solubility in water in g/100g
2 · 10-4 @0-60°C
Mohs hardness
6
Knoop hardness in kg/mm²
415
Material type
single crystalline, synthetic
Crystal type
tetragonal
Crystal structure
tP6
Lattice constant in Å
a = 4,0623

c = 3,053

Elastic coefficient in GPa
C11 = 138

C12 = 88

C13 = 62

C33 = 201

C44 = 56,5

C66 = 98,6

Young's Modulus (E) in Gpa
138,55
Shear Modulus (G) in GPa
54,66
Bulk Modulus (K) in GPa
101,32
Rupture Modulus in MPa
60
Apparent elastic limit in MPa
49,6
Poisson's ratio
0,276
Spectral properties
sample thickness: 2 mm
Optical Properties
Transmission range in µm @10% min. 0.12 - 9.6
Transmission range in µm @50% min. 0.12 - 8.5
Refractive index @ 633nm 1.375 (no)
1.389 (neo)
Reflection losses in % at 1 surface 2.52 @ 633nm
Reflection losses in % at 2 surfaces 11.2 @ 120nm
dn/dT in 1/K 2.3 · 10-6 (parallel c-axis)
1.7 · 10-6 (perpendicular c-axis)
Physical Properties
Density in g/cm³ 3.177
Melting point in °C 1255
Specific heat capacity in J/(kg · K) 1004
Thermal Conductivity in W/(m · K) 21 (parallel) @300K
33.6 (perpendicular) @300K
Thermal Expansion in 1/K 13.7 · 10-6 (parallel)
8.9 · 10-6 (perpendicular)
Dielectric constant 4.87 (parallel)
5.45 (perpendicular)
Solubility in water in g/100g 2 · 10-4 @ 0-60°C
Mohs hardness 6
Knoop hardness in kg/mm² 415
Material type Single crystal, synthetic
Crystal type tetragonal
Crystal structure tP6
Lattice constant in Å a = 4.0623
c = 3.053
Elastic coeficients in GPa C11 = 138
C12 = 88
C13 = 62
C33 = 301
C44 = 56.5
C66 = 95.5
Young's Modulus (E) in GPa 138.55
Shear Modulus (G) in GPa 54.66
Bulk Modulus (K) in GPa 101.32
Rupture Modulus in MPa 60
Apparent elastic limit in MPa 49.6
Poisson ratio 0.276
Spectral Properties