Multi-Anvil High Pressure Laboratory

The multi-anvil laboratory has specialized equipment for treating a variety of samples under high pressure and temperature conditions.  For many chemical compounds, this pressure treatment creates unique, dense forms that are otherwise unattainable.  The best-known application of simultaneous high pressure and temperature is in the production of synthetic diamonds.  In our laboratory, we can make diamonds, but we can also reach pressures up to five times higher than the pressure that is normally used to make diamonds.  With this capability, we can perform a wide variety of novel research using high pressures.  Many of the experiments we perform in our three multi-anvil presses are "cook and look;" in other words, we subject the samples to high pressure and temperature, but we can examine them only after the pressure is released.  Typical methods used to examine the high-pressure products include x-ray diffraction, electron probe microanalysis, and transmission electron microscopy.  Typical sample sizes are in the millimeter range.  We also have equipment for measuring electrical conductivity and impedence on samples while they are subjected to high pressure and temperature.

The multi-anvil laboratory is partnered with a diamond-cell laboratory, which is not yet an official Chemistry facility.  In the diamond-cell laboratory, samples can be treated to high pressure and high temperature, but in this case the samples can also be observed optically and probed using visible light during the treatment, because the diamond anvils are transparent.  Sample sizes are in the tens of microns. 

The combination of multi-anvils and diamond cells results in a wide variety of possible high pressure experiments in our Department.

The 10/5 assembly under construction.  The ceramic octahedron with pre-cut grooves is visible; the edge of the octahedron is 10 millimeters.  Inside the octahedron is a dark sleeve made of lanthanum chromite ceramic, and the metal tabs are the end of the rhenium furnace.  The sample goes inside the hole in the middle, and the thermocouple wires will run through the pre-cut grooves.

A later stage in the construction of the 10/5 assembly.  This shows the other side of the octahedron.  The thermocouple is visible
as a small metal cross at the center of the assembly where the two thermocouple wires make contact.  The two legs of the thermocouple can be seen coming out of both sides of the assembly, inside of two thin ceramic insulating tubes.

Kurt Leinenweber

Director of Multi-Anvil High Pressure Laboratory
Lab: D-51
Phone: (480) 965-8853
Email: Kurtl@asu.edu