In collaboration with
Oxford Cryosystems we co-developed
the pHeniX cryostat which allows powder samples to be routinely measured down
to 12 K. The design of the cyrostat means that sample loading is extremely
easy and rapid. Temperature control is achieved via cryopad software
running on a PC and base temperature is achieved in as little as 40 minutes.
The design of the rotating seals is such that theta-2theta scans can
be performed to high angle with minimal stress on the high pressure hoses.
See the movies below to see the pHeniX in action!
Click below to download .mpg images of the phenix "in action" - warning approx 700 Kb each!
ZrW2O8 Cell Parameter as a Function of Temperature
Red points show experimental data collected using the pHeniX mounted on a Bruker D8 diffractometer.
Blue solid line is a fit to a simple theoretical model of the thermal contraction of this phase.
The coefficient of thermal expansion of this material derived from the PheniX data is -9.5 x 10-6 K-1 between 20 and 294 K, identical to that derived from the best available neutron diffraction data over the same temperature range.
The total experimental time used for this experiment was 48 hours.
[Modified 10-Apr-2021 by John S.O. Evans. Pages checked for Google Chrome.]