Applications | Fourier Transform Infra-Red (FTIR) Spectroscopy
Fourier transform infra-red (FTIR) spectroscopy is often used to characterize the structure and temperature-dependent performance of materials including liquids, solids, gases, and thin films. In the simplest FTIR spectrometer arrangement, a sample is located in the beampath before the detector. Two spectra are obtained for each measurement, (a reference spectrum with no sample in the beampath and a second spectrum with sample installed). The ratio of these two spectra produce the measurement used by the researcher.
Introduction of a cryostat for sample cooling adds a degree of complication to the procedure. The reference spectrum must now be taken with the cryostat installed in the beampath (to incorporate the cryostat optics into the reference measurement). In most cases, the cryostat is then removed from the spectrometer for sample installation, and reinstalled to make the actual sample measurement. The process of cryostat removal, sample mounting, and cryostat reinstallation can require from thirty to sixty minutes, limiting the number of samples that can be characterized per day. In addition, the cryostat must be reinstalled in the identical position on the spectrometer for each subsequent sample measurement. If the cryostat position changes, the reference measurement will no longer be valid due to small variations in the cryostat optical path.
The Janis range of cryostats for FTIR address these limitations while providing a sample environment that is best suited for your application. Options for FTIR spectroscopy include:
- Multiple sample mounting provisions, allowing the user to switch between a reference path and several samples without moving the cryostat.
- Precision linear and rotary manipulators, manually controlled
- Precision linear and rotary manipulators, remotely controlled
- Sample in vacuum or sample in dynamic or static exchange gas
- Liquid nitrogen or closed-cycle refrigerator cooling
- Mounting flange to fit many commercially available spectrometers
- IR windows, including ZnSe, polyethylene, polypropylene, sapphire, diamond, and more
- Windows are available wedged for reduced interference or plane parallel
- High-temperature operation (ST-100-FTIR, VPF-100-FTIR, and PT-950-FTIR with sample in vacuum)
The SuperTran and SuperTran-VP systems for FTIR include a high-efficiency transfer line for low cryogen consumption and feature additional spacers for minimal vibration. Our pulse tube system for FTIR features very low vibrations—particularly on the room temperature housing—allowing the cryostat to be mounted directly on the spectrometer. The flexibility of Janis' design and the range of options available, combined with a reputation for quality, make the Janis FTIR cryostats the ideal choice for efficient and high-quality FTIR measurements.
Existing designs include:
- Continuous flow cryostat with sample in vacuum — ST-100-FTIR
- Continuous flow cryostat with sample in vapor — STVP-100-FTIR
- Liquid nitrogen pourfill cryostat — VPF-100-FTIR
- Low vibration pulse tube — PT-950-FTIR
As with all Janis cryostats these designs may be modified to suit your individual requirements. Contact Janis today to discuss how an FTIR cryostat may be integrated with your spectrometer system.
|Sample environment||Vacuum||Liquid or flowing vapor||Vacuum||Exchange gas|
|Temperature range||~2.5 K to 325 K (higher temperatures optional)||~2 K to 300 K||65 K to 325 K (higher temperatures optional)||~7 K to 300 K (higher temperatures optional)|
|Initial cooldown time||15 min||15 min||15 min||N/A|
|Temperature stability (with controller)||50 mK or less|
|Orientation||Any position||Vertical for <4.5 K||Vertical||Vertical|
|System weight||Approximately 10 lb (minus the transfer line)||Approximately 15 lb (minus the transfer line)||Approximately 10 lb||Approximately 70 lb (minus the compressor)|
|Cryogen consumption (cooldown)||0.4 L LHe from 325 K to 4.2 K||0.5 L LHe from 325 K to 4.2 K||N/A||N/A|
|Cryogen consumption (operation)||0.5 L/h at 5 K with LHe||1.1 L/h at 5 K with LHe||0.1 L/h at 77 K with LN2||N/A|
Note: Specifications do not include parasitic or experimental heat loads.
Contact Janis today for details of how our systems can be integrated into your laboratory.
Cryostats for FTIR datasheet (PDF, 1542 KB)