Our nitrogen cryostat, OptistatDN is ideal for experiments requiring 77 K base temperature, high sample throughput and for samples which are difficult to cool by conduction. Its small footprint is ideal in laboratory where space is limited. No external dewar or transfer tube are required.Nitrogen cryostat 77K, sample in exchange gas - OptistatDN

  • Wide temperature range: from 77 K to 500 K
  • Quick sample change in less than 5 minutes via top-loading sample probe
  • 15 hours cryogen hold time before refills required providing the convenience of a full working day operation
  • Superb optical access (f/1) for measurements requiring light collection
  • Optimised clear beam throughput (15 mm diameter aperture) allows a large illumination area for measurements involving the detection of low intensity light
  • Versatile: wide range of sample holders/rods including liquid cuvette for liquid samples and simple/precise height adjust/rotate sample rod
  • Electrical measurements via 10-pin electrical feed wire to heat exchanger
  • Compact size allowing easy integration into commercial spectrometers



Temperature range 77 - 500 K*
Temperature stability ± 0.1 K (measured over 10 min period)
Maximum sample space 20 mm diameter
Sample holder dimensions 19 mm wide x 30 mm long
(optical sample holder version has a 15 mm aperture)
Cool down from ambient to 77 K (mins) 25
Liquid nitrogen capacity 1.2 L
Hold time at 77 K ≥ 15 hours

System Components/Options

A typical system consists of:

  • OptistatDN nitrogen cryostat
  • Sample holder and rod
  • Up to five sets of windows. (four radial; one axial). Each set includes two windows (radiation shield and outer case windows)
  • New Mercury iTC temperature controller
  • High vacuum pumping system

 Optional items:

  • Wiring and electrical connections to the sample
  • Simple height adjust and rotate sample rod: provides sliding adjustment with locking screws to hold a fixed position. The range of vertical motion is 32 mm. Positioning accuracy is 0.5 mm( height) and 1 degree (rotation).
  • Precise height adjust and rotate sample rod provides height adjust and with a resolution of 10 µm and a goniometer for setting the rotation angle with a resolution of 12 minutes.
  • Liquid cuvette for liquid samples


  • A wide range of window materials can be fitted to the OptistatDN to meet specific spectroscopy applications
  • Special windows with non-parallel faces and anti-reflection coatings are available
  • Additional or replacement window flanges available via the Oxford Instruments Direct - Cryospares® online catalogue

Sample holders/rods options

Adding to the OptistatDN versatility is the ability to fit several different sample rods and holders:

  • Standard sample rod: single sample holder with 10-pin electrical access
  • Simple height adjust and rotate sample rod: height adjust range 32 mm with positioning accuracy 0.5 mm, rotate adjust range 360° with positioning accuracy 1°
  • Precision height adjust and rotate sample rod: Height adjust range 30 mm with 10 µm resolution, rotate adjust range 360° with 12 minutes resolution
  • In addition to the sample positioning and 10-pin electrical access, both height adjust and rotate sample rods feature a double sample holder. For applications such as FTIR, the reference and sample can be measured without having to move the cryostat or exchange samples
  • A liquid cuvette sample holder enables liquid sample experiments
  • Additional or replacement sample rods are available via the Oxford Instruments Direct - Cryospares online catalogue

See also the OptistatDN-V for this cryostat with sample in vacuum.



The OptistatDN cryostat cools samples using liquid nitrogen from an integral nitrogen reservoir. Liquid nitrogen, stored in the upper part of the cryostat, is gravity fed to a heat exchanger surrounding the sample tube. The sample is then cooled by conduction via a helium or nitrogen exchange gas in the sample space.

A vacuum case surrounds the nitrogen reservoir and heat exchanger. It needs to be pumped to high vacuum (lower than 10-4  mbar). An activated charcoal sorb is fitted to the nitrogen reservoir. This continuously pumps the residual gases from the OVC to maintain good thermal isolation.

Changing the sample simply involves removing the sample rod maintaining overpressure of exchange gas , replacing the sample and inserting the rod back into the cryostat. There is no needs to break the insulating vacuum and warm the cryostat up. The resulting sample change times are very short, typically few minutes.

Temperature control is achieved by a combination of manual nitrogen flow control and power dissipated in an electrical heater, regulated using a temperature controller.


UV / Visible spectroscopy: Experiments at low temperatures reveal the interaction between the electronic energy levels and vibrational modes in solids.

Infra-red spectroscopy : Low temperature IR spectroscopy is used to measure changes in interatomic vibrational modes as well as other phenomena such as the energy gap in a superconductor below its transition temperature.

Raman spectroscopy : Lower temperatures result in narrower lines associated with the observed Raman excitations.

Photoluminescence : At low temperatures, spectral features are sharper and more intense, thereby increasing the amount of information available.

Gas absorption : We have developed a special cryostat in partnership with Quantachrome Instruments to fit their autosorb-iQ gas sorption analysers.

Case study:

Dr Ken Haenen and Prof Jean Manca (Limburg University, Diepenbeek - Belgium) use the OptistatDN in combination with a FTIR spectrometer to perform Fourier Transform Photoconductive Spectroscopy FTPS. FTPS is a highly sensitive photocurrent method for materials with low optical absorption such as conjugated polymer and CVD-diamond films, which are developed for novel electronic, and bio-electronic applications.

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