CsBr SC-IR
Grade · default condition
SC-IR = bridgman-grown optical single crystal, IR window grade
Choose the Bridgman-grown single crystal for 0.2–40 µm far-infrared windows, prisms and beamsplitter substrates, and keep it in a dry environment during service.
Values for the SC-IR condition
Other CsBr tempers and conditions
CsBr is listed in 3 conditions; see the grade overview at CsBr.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Europium-doped storage-phosphor / scintillator grade | Pick the europium-doped grade for columnar needle-structure photostimulable storage screens in X-ray imaging plates; it is not intended for infrared transmitting windows. | — | 6 | 1.5 | 19 HV | 0.9 W/m·K |
SC-IRDefaultThis page Bridgman-grown optical single crystal, IR window grade | Choose the Bridgman-grown single crystal for 0.2–40 µm far-infrared windows, prisms and beamsplitter substrates, and keep it in a dry environment during service. | — | 6 | 2 | 20 HV | 0.94 W/m·K |
Hot-pressed / forged polycrystalline CsBr blank | Use the hot-pressed or forged polycrystalline blank when higher mechanical strength and larger apertures are needed and slight scattering can be tolerated. | — | 12 | 1 | 25 HV | 0.88 W/m·K |
What is CsBr SC-IR?
CsBr SC-IR is CsBr in the SC-IR grade — choose the Bridgman-grown single crystal for 0.2–40 µm far-infrared windows, prisms and beamsplitter substrates, and keep it in a dry environment during service. CsBr SC-IR has a tensile strength of 6 MPa (0.87 ksi), weaker than 94% of glass grades. Elongation at break is 2% and the elastic modulus is 15.8 GPa (2.29 Msi). CsBr SC-IR has a density of 4.44 g/cm³ (0.16 lb/in³), heavier than 75% of glass grades. It melts at 636°C (1,177 °F).
Advantages
- Easy to machine — 55/100, better than 93% of glass grades
- Ductile — tolerates forming and impact — 2%, better than 84% of glass grades
Limitations
- Low fracture toughness — 0.1 MPa·√m (0.091 ksi·√in), worse than 100% of glass grades
- Low stiffness — 15.8 GPa (2.29 Msi), worse than 98% of glass grades
- Needs corrosion protection — 8/100, worse than 94% of glass grades
- Hard to polish — 55/100, worse than 85% of glass grades
- Poor heat conductor — 0.94 W/m·K (0.543 BTU/hr·ft·°F), worse than 81% of glass grades
CsBr SC-IR properties
Typical room-temperature values for CsBr SC-IR; 15 are specific to this condition. Other listed values are CsBr reference data and may not represent this condition. Bars are the position among glass grades.
Physical5
CsBr SC-IR has a density of 4.44 g/cm³ (0.16 lb/in³), heavier than 75% of glass grades. It melts at 636°C (1,177 °F).
Mechanical13
CsBr SC-IR has a tensile strength of 6 MPa (0.87 ksi), weaker than 94% of glass grades. Elongation at break is 2% and the elastic modulus is 15.8 GPa (2.29 Msi).
Thermal5
CsBr SC-IR is rated for continuous service to 300°C (572 °F). It conducts heat at 0.94 W/m·K (0.543 BTU/hr·ft·°F), worse than 81% of glass grades. Thermal expansion is 47.9 µm/m·K (26.6 µin/in·°F).
Electrical3
CsBr SC-IR has an electrical resistivity of 1×10¹⁰ Ω·m.
Chemical & Environmental2
Corrosion resistance is not recommended (8/100), worse than 94% of glass grades.
Manufacturability2
CsBr SC-IR's machinability is good (55/100, better than 93% of glass grades).
Common Calculations4
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with CsBr SC-IR
Is CsBr easy to machine?
Turn at low speed with sharp single-crystal diamond tools or cut dry with a wire saw; the crystal cleaves on {100}. Do not use water-based coolant, and dehumidify the machining enclosure.
Can CsBr be welded?
Not weldable; hold optics with mechanical retaining rings, dry-sealed O-rings or low-temperature optical cement.
Can CsBr be formed, bent or molded?
Blanks come from Bridgman–Stockbarger or Czochralski melt growth, or from hot-pressed/hot-forged polycrystalline billets. The material cannot be cold formed.
What surface finishes work on CsBr?
Polish with dry polishing powder carried in anhydrous ethanol or kerosene. Finished parts can be coated with KRS-5, Ge or polymer moisture barriers and must be stored in a desiccator at all times.
CsBr 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 |
|---|---|---|
| Csstoichiometric CsBr | 62.2 – 62.7 | 62.45 |
| Euonly in CsBr:Eu storage-phosphor variant | 0 – 0.5 | 0.1 |
| Br | ≥ 37.3 (balance) | — |
CsBr SC-IR — frequently asked
What is CsBr SC-IR used for?
CsBr SC-IR is typically used for far-IR spectroscopy windows, IR prisms and FTIR components. In short: transmits to 40 µm; very soft, hygroscopic halide; doped storage-phosphor grade.
What is the tensile strength of CsBr SC-IR?
CsBr SC-IR has a typical tensile strength of 6 MPa (0.87 ksi) — weaker than 94% of glass grades. Strength varies by condition: see the 3 listed tempers.
Is CsBr SC-IR easy to machine?
Reasonably — machinability is rated good (55/100, better than 93% of glass grades). Turn at low speed with sharp single-crystal diamond tools or cut dry with a wire saw; the crystal cleaves on {100}. Do not use water-based coolant, and dehumidify the machining enclosure.
Can CsBr SC-IR be welded?
Not weldable; hold optics with mechanical retaining rings, dry-sealed O-rings or low-temperature optical cement.
What surface finishes work on CsBr SC-IR?
Polish with dry polishing powder carried in anhydrous ethanol or kerosene. Finished parts can be coated with KRS-5, Ge or polymer moisture barriers and must be stored in a desiccator at all times.
Can CsBr SC-IR be formed, bent or molded?
Blanks come from Bridgman–Stockbarger or Czochralski melt growth, or from hot-pressed/hot-forged polycrystalline billets. The material cannot be cold formed.
What is the maximum service temperature of CsBr SC-IR?
CsBr SC-IR is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- Handbook of Optical Materials — CRC Press (Weber) (2003)
- CRC Handbook of Chemistry and Physics — CRC Press (2020)
- CsBr IR window / crystal datasheet — Korth Kristalle GmbH (2022)
- Refractive index and dispersion of alkali halides — J. Phys. Chem. Ref. Data (1976)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.