Potassium bromide
Material
KBr
Potassium bromide (KBr) is characterized by high transparency in the wavelength range between 0.25 µm and 26 µm. It can be used at temperatures above 300 °C and shows no optical absorption in the areas of high transmission. Potassium chloride is hygroscopic and highly soluble in water. For these reasons, it must be stored in a dry environment or protected against moisture by a special protective coating. Its chemical, optical and mechanical properties make potassium bromide a useful material for components of IR spectroscopy and beam splitters for CO2 lasers.
Properties
Optische Eigenschaften | |
---|---|
Transmissionsbereich in µm (Minimum 10%) | 0,2‐25 |
Transmissionsbereich in µm (Minimum 50%) | 0,23‐25 |
Brechungsindex @633nm | 1,557 (1,537 @10µm) |
Reflexionsverluste in % an 1 Oberfläche | 4,34 @10µm
|
Reflexionsverluste in % an 2 Oberflächen | 8,3 @10µm
|
dN/dT in 1/K | -40,83 · 10-6
|
Physikalische Eigenschaften | |
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Dichte in g/cm3 | 2,753
|
Schmelzpunkt in °C | 730 |
Spezifische Wärmekapazität in J/(kg · K) | 435
|
Thermische Leitfähigkeit in W/(m · K) | 4,8
|
Thermische Ausdehnung in 1/K | 43 · 10-6
|
Dielektische Konstante | 4,9
|
Wasserlöslichkeit in g/100g | 67,8 @25°C |
Mohs-Härte | 1,5 |
Knoop-Härte in kg/mm² | 7 (<100>)
|
Materialtyp | Einkristall, synthetisch
|
Kristalltyp | kubisch, flächenzentriert |
Kristallstruktur | Fm3m
|
Gitterkonstante in Å | a = 6,598
|
Elastizitätskonstanten in GPa | C11 = 34,5 C12 = 5,4 C44 = 5,08 |
Elastizitätsmodul (E) in GPa | 26,8 |
Schubmodul (G) in GPa | 5,08 |
Kompressionsmodul (K) in GPa | 15,03 |
Biegefestigkeit in MPa | 3,3
|
Dehnungsgrenze in MPa | 3,3
|
Poissonzahl | 0,3 |
Spektrale Eigenschaften |
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Probendicke: 2 mm |
Optical Properties | |
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Transmission range in µm @10% min. | 0.2 - 25 |
Transmission range in µm @50% min. | 0.23 - 25 |
Refractive index @ 633nm | 1.55655 (1.537 @10µm) |
Reflection losses in % at 1 surface | 4.34 @ 10µm |
Reflection losses in % at 2 surfaces | 8.3 @ 10.6µm |
dn/dT in 1/K | -40.83 · 10-6 |
Physical Properties | |
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Density in g/cm³ | 2.7533 |
Melting point in °C | 730 |
Specific heat capacity in J/(kg · K) | 435 |
Thermal Conductivity in W/(m · K) | 4.8 |
Thermal Expansion in 1/K | 43 · 10-6 |
Dielectric constant | 4.9 |
Solubility in water in g/100g | 67.8 @ 25°C |
Mohs hardness | 1.5 |
Knoop hardness in kg/mm² | 7 (<100>) |
Material type | Single crystal, synthetic |
Crystal type | cubic face-centered |
Crystal structure | Fm3m |
Lattice constant in Å | a = 6.598 |
Elastic coeficients in GPa | C11 = 34.5 C12 = 5.4 C44 = 5.08 |
Young's Modulus (E) in GPa | 26.8 |
Shear Modulus (G) in GPa | 5.08 |
Bulk Modulus (K) in GPa | 15.03 |
Rupture Modulus in MPa | 3.3 |
Apparent elastic limit in MPa | 3.3 |
Poisson ratio | 0.3 |
Spectral Properties | |
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