A fundamental experimental apparatus used in our science is the diamond anvil cell. The diamond anvil cell (DAC) is one of the most popular devices for the study of matter under high pressure. Diamond anvil cells operate under the principal that pressure equals force over area. Force is applied to the material under study through precisely aligned opposing diamond anvils. Typically, a thin gasket restrains the sample being compressed. A small sample of ruby crystal may be used as an internal pressure sensor. Beams of radiation focused to contact the material help probe the behavior and properties of the material under pressure. The DAC is designed to provide high mechanical stability, accessibility of the sample to probes of emitted radiation, reliability at high and low temperatures, and may be constructed for magnetic measurements.
The National Institute of Standards and Technology (NIST) has made available a nice early history of the DAC in The Diamond Anvil Pressure Cell. Furthermore, The diamond cell stimulates high-pressure research discusses the DAC and the ruby fluorescence method of measuring pressure, developments which were accomplished through efforts of the National Bureau of Standards (now NIST) and Block and Piermarini. A more extensive review of diamond anvil cell use may be found in Diamond anvil cell and high-pressure physical investigations from Reviews of Modern Physics vol. 55, no. 1, January 1983. Finally, Bassett celebrates the apparatus in Diamond anvil cell, 50th birthday High Pressure Research, vol. 29, issue 2, 163-186, June 2009.
HiPSEC owns a number of DACs, including over a dozen designs — several developed at UNLV.
Paderborn-Panoramic Diamond Anvil Cell
The Paderborn-panoramic style diamond anvil cell is primarily used for nuclear resonant inelastic x-ray scattering (NRIXS) and nuclear forward scattering (NFS) techniques to determine phonon density of states. Its prime feature is that it has two large openings in the cylinder to allow the APD detectors to fit inside without compromising the ability to create pressure. The cell is machined in steel or CuBe for magnetic NFS measurements. The cell can also be used in the gas loading system at the Advanced Photon Source with a specially designed gear box. A beam line detector assembly at the Advanced Photon Source is shown with the DAC installed.
Tanis, E.A., Giefers, H., and Nicol, M.F., Novel rhenium gasket design for nuclear resonant inelastic x-ray scattering at high pressure, RSI, 79, 023903 (2008). DOI Giefers, H.,Tanis, E.A., et al., Phonon Density of States of Metallic Sn at High Pressure, PRL, 98, 245502 (2007). DOI
Piston Cylinder “Mao type” Symmetric Cell
Characteristics of this cell are that it is versatile, easy to use and very stable. It is possible to achieve pressures greater than 300 GPa in the cell. The fairly wide opening is also good for Angular Dispersive X-Ray Diffraction. Our cell is equipped with Type II Diamonds having low infra-red absorption. Our cell was purchased from Princeton University.
H. K. Mao, P. M. Bell, J. W. Shaner, and D. J. Steinberg Specific volume measurements of Cu, Mo, Pd, and Ag and calibration of the ruby R1 fluorescence pressure gauge from 0.06 to 1 Mbar. J. Appl. Phys. 49, 3276 (1978). DOI
Syntec Symmetric DAC with Spherical Seat for Tilt Adjustment
This diamond anvil cell is designed for use in powder diffraction and spectroscopy. It features a spherically-shaped seat for micro-adjustment of diamond anvil tilt. Its adjustments allow for near perfect diamond alignment. The adjustment control combined with a reduced seat opening permit very high pressures to be achieved (over 1Mbar, depending on anvil size).
Two Posts Wide-opening Cells
Designed at UNLV by Oliver Tschauner, Jim Norton and Amadeo Sanchez, these cells are particularly well suited for single crystal diffraction. However, they are also convenient for use in powder diffraction and optical spectroscopy. They have a wide axial opening and tilting adjustments.
Hydrothermal Diamond Anvil Cell
The HDAC was developed by Bassett et al. (1993) DOI . The cell is equipped with resistive alumel-chromel wires coiled around a tungsten carbide seat which supports each diamond anvil. Two K-type (NiCr/NiAl) thermocouples, attached very close to each diamond culet, are used to measure temperature. The HDAC is heated resistively by using variable transformers that facilitate flexible heating rates and temperature to be maintained constantly to ±5 °C of the target temperature. The cell has the ability to reach moderate pressures (up to 10 GPa) and temperatures up to 1000C. The HDAC is currently being used for x-ray fluorescence experiments to determine trace element solubility.
Mao-Bell Diamond Anvil Cell
This cell type was originally developed by Mao and Bell.* at the Carnegie Institution of Washington in the Geophysical Laboratory. It is a piston cylinder based cell. Normal and miniature cells are shown above.
*High-Pressure Physics: Sustained Static Generation of 1.36 to 1.72 Megabars. Science, New Series, vol. 200 no. 4346, pp. 1145-1147, June 1978. “Observations of Hydrogen at Room Temperature (25°C) and High Pressure (to 500 Kilobars). Science, New Series, vol. 203, no. 4384, pp. 1004-1006, March 1979.
Merrill-Bassett type Diamond Anvil Cell
This miniature diamond anvil cell was designed to perform optical and x-ray diffraction studies on single crystals under hydrostatic pressure. It is small enough to mount on a goniometer head and can be used with a precession camera and single crystal orienter.
The cell was originally described in Miniature diamond anvil pressure cell for single crystal x-ray diffraction studies in Review of Scientific Instruments vol. 45, 290 (1974).
Gas Membrane Diamond Anvil Cell
This diamond anvil cell is equipped with a gas membrane for pressurization. This system provides fine remote control of pressure in the cell. When coupled with a ruby pressure spectrometer it can allow continuous measurement at synchrotron facilities.
R. Le Toullec et. al. describe such a cell in The membrane diamond anvil cell: A new device for generating continuous pressure and temperature variations, High Pressure Research, vol. 1, no. 1, 77-90, 1988.
Copper Beryllium Diamond Anvil Cell
The housing of this cell is made of Copper Beryllium (CuBe), which is non-magnetic. Magnetic susceptibility, resistivity, or conductivity experiments can be performed on materials using this cell with designer anvils.* Its relatively small size permits its use in our Physical Property Measurement System (PPMS) with a 9 T magnet. Our copper beryllium cell was purchased from D’Anvils Corporation.
* Designer anvils are fabricated with electrical microprobes and microcircuits embedded in the diamond anvil rather than external to the anvil. A nice overview of the technology along with scanning electron micrographs of anvils may be found in Science & Technology Review December 2004 from Lawrence Livermore National Laboratory. The technology was originally described by D. D. Jackson et. al. in Magnetic susceptibility measurements at high pressure using designer diamond anvils, Review of Scientific Instruments, 74(4), 2467 (2003).
Bridgman* Style Transport Cell
While not a diamond anvil cell, this is instead an opposed anvil tungsten carbide cell. This cell uses the split gasket design with a 6 mm culet and 6 mm annular pyrophyllite outer gasket with a 2 mm disk steatite inner gasket for a pressure medium. This cell was designed at UNLV by Matthew Jacobsen, James Norton and Amadeo Sanchez. It is designed for electrical and thermal measurements. It has been recently commissioned and has been tested to be routinely capable of 18 GPa. The cell pressure is applied through use of a Carver model hydraulic press. This press is coupled to a pressure transducer for easy computer interfacing and has been calibrated using Bi, Sn and Pb electrical transitions.
*Percy Williams Bridgman, The Resistance of 72 Elements, Alloys and Compounds to 100,000Kg/Cm2. Proceedings of the American Academy of Arts and Sciences 81, 165-251 (1952).