Silver Chloride

Silver Chloride is commonly used for infrared optics in wide spectrum band from 0.4 µm to 30 µm. Silver Chloride is grown into small ingots by the sealed-ampoule Stock Barger techniques. It is usually available as a white crystalline solid. However, due to its light sensitivity it can turn a deep grey blue upon prolonged exposure to light. This is due to its decomposition to silver metal and chlorine.

Silver Chloride is very soft and shows (under pressure) cold liquidity. It is relatively insoluble in water, but can be dissolved in aqueous solutions of ammonia, potassium cyanide and sodium thiocyanate. It is corrosive in combination with metals, therefore binders has to consist of silver or teflon.

Silver Chloride (AgCl) is commonly used for infrared transmission windows, in gas and liquid sample cells used with infrared and FTIR spectrophotometers in place of Potassium Bromide (KBr) with aqueous samples that would attack KBr optics.
Optical Properties
Transmission range in µm @10% min. 0.41 - 24.5
Transmission range in µm @50% min. 0.42 - 24.5
Refractive index @ 633nm 2.05678
(1.98 @10µm)
Reflection losses in % at 1 surface 10.82 @ 10µm
Reflection losses in % at 2 surfaces 19.5 @ 10µm
dn/dT in 1/K -61 · 10-6
Physical Properties
Density in g/cm³ 5.589
Melting point in °C 457
Specific heat capacity in J/(kg · K) 355
Thermal Conductivity in W/(m · K) 1.2
Thermal Expansion in 1/K 31 · 10-6
Dielectric constant 12.3
Solubility in water in g/100g 1.9 · 10-4 @ 25°C
Mohs hardness 1.5 - 2
Knoop hardness in kg/mm² 9.5
Material type Single crystal, synthetic
Crystal type cubic
Crystal structure Fm3m
Lattice constant in Å a = 5.547
Elastic coeficients in GPa C11 = 59.6
C12 = 36.1
C44 = 6.22
Young's Modulus (E) in GPa 22.9
Shear Modulus (G) in GPa 7.099
Bulk Modulus (K) in GPa 44.04
Rupture Modulus in MPa 26
Apparent elastic limit in MPa 26.2
Poisson ratio 0.41
Spectral Properties