Past and Present of Large Volume
Press Technique
(Experiments with Large Sample Volumes)
Natalia Dubrovinskaia
Mineralphysik und Strukturforschung
Institut für Geowissenschaften
Universität Heidelberg
Germany
Outline
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Nomenclature and definitions
Methods for generating static pressures
Evolution over past 50 years
Examples
Some Definitions
P = F/A
P = Pressure
F = Force
A = Area
So
High Pressure can be achieved with:
Larger force-->bigger sample volume
Smaller area-->smaller samples
Methods for Generating Static
Pressures
Extreme values of intensive properties
(pressure, temperature, voltage) may me
obtained through:
• Disproportionation
• Gathering and focusing
• In situ energy transformation
Disproportionation
"Give me a place to stand and, with lever, I will move the
world."
(Archimedes)
Hydraulic pumps and rams operate on similar principles
to those used by levers and make it possible to exert
very large forces on small areas, thus giving rise to high
pressures. Pressures derived by transferring the large
thrust of a hydraulic ram to a small area (to generate
high pressure) are limited by the compressive strength of
the transferring material. Limitation imposed by the
strengths of materials can sometimes be circumvented
by inventive design. Geometrical considerations increase
the pressures obtainable from high-pressure devices.
Landmark HP Devices
(in order of their development)
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(1) piston-cylinder,
(2) Bridgman anvil,
(3) the belt, and
(4) multiple anvils, the principal multianvil
types being the tetrahedral press and the
cubic press
All other devices, by whatever name they
may be called, are derivatives of these!
Piston-cylinder
• Origins lost in antiquity
• HPHT importrant
adaprtations due to
Parsons & Coes
• P ~ 5 GPa
• Upper pressure limit is
set by failure of the
piston
A piston confined by the cylinder drives the
smaller piston into its cylinder, this being
the disproportionation principle. In the field
of hydraulics this type of device is called an
intensifier.
Parsons
P~1.5 GPa, T~ 3000°C
1880-1928 diamond synthesis
program
&
Coes
Coes, Science (1953)
P~3.5 GPa, T= 500-800°C
Piston-cylinder
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Piston-cilinder device of tungsten
carbede using two rams
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For the highest pressure the cobalt
content should beonly 3%. Such a
tungsten carbide is very brittle.
Therefore the alignment of the piston
and the cylinder and the hydraulic
ram providing the thrust must be
nearly perfect to prevent off-axis
loading.
A double-ended piston-and-cylinder
device requires extra special care in
the alignment and in the parallelism
of the various components with the
moving elements of the hydraulic
press.
The piston should be as short as
possible and should protrude as little
as possible from the bore of the
cylinder. The protruding part of the
pistonis the weak part, and fracture
will usually occur there.
A tight-fitting collar around a portion
of the protruding part of the piston is
very helpful in preventing breakage
on the exposed piston ends.
Simple
Cell
Assembly
Can one really perform "hydrostatic" experiments on solid substances?
“Frictional holdup”; geometrical effects
Cell assembly for internal resistance heating
Hysteresis loop for pyrophylite
Because of the hysteresis in solid pressure transmitting substances (apparatus
friction also enters in), calibration of pressure apparatus is usually made on a
basis of ascending (increasing) pressure only!
Opposed –Anvil Devices
The massive support principle
Opposed –Anvil Devices
Bridgman‘s anvil
Percy W. Bridgman (1882-1961)
The Nobel Prize in Physics 1946
0.6 mm
10 mm
Pipestone
AgCl
Main disadvantage: pressure gradients due to anvils deformation and elasticity
Pressure calibration
General Electric Diamond Project
Left to right are Drs. Francis P. Bundy, Herbert M. Strong, H. Tracy Hall and
Robert Wentorf. Anthony Nerad was the project manager and J.E. Cheney
was an assistant to Drs. Strong and Bundy. Also assisting the physicists
was Hal Bovenkerk (not shown).
In the fall of 1951 General Electric assembled a team of scientists charged with the task of
transforming carbon into diamond. This is the giant double-acting press that was built at a cost of around 125,000 1951
dollars with the aim of synthesizing diamonds. The behemoth was built in Birdsboro, Pa. and its construction took
nearly two years. The two rams were eventually tied together to give it the capability of delivering 1000 tons of force.
This is the press identified in GE press releases as the one on which diamonds were first made. The Watson-Stillman
press on which diamonds were in fact first synthesized is visible in the lower left-hand side of the picture.
H. Tracy Hall and Robert Wentorf
The Belt Apparatus
(1953)
H. Tracy Hall
(1919-2008)
-The massive support principle
(tapered piston)
-tapered conical chamber
-Increased stroke as combined
effect of double-ending,
tapered gasket and sanwiched
gasket
-allows higher P than PC at the
same cost and no need in
clamping cylinder
-not sensitive to misalignment
soapstone (steatite), pyrophylite
The Belt
T. Hall
F. Bundy
Diamond Production
30,000 ton press in NIRIM, Tsukuba, Japan
Belt Apparatus
Max P=6 GPa
Cell Volume=1 liter
Uniaxial
Multiaxial
from Roy and White (1964)
Disadvantages of uniaxial devices
Opposed-anvil, piston-and-cylinder, the belt- uniaxial devices.
The means for mechanically reducing the volume of a substance is
accomplished by moving certain apparatus components toward
each other along a line.
When quasi-hydrostatic pressure transmitting materials are used,
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pressure gradients will invariably be set up within the cell in a
pattern depending on the movement of the compressing members;
a barrel shape of final sample;
the sintered product will tend to delaminate (break into several
disks perpendicular to the axis of compression) after pressure is
released
This problem can be overcome to some extent by surrounding the
heater sample tube with a material that is more hydrostatic than
pyrophyllite, for example, sodium chloride
Multi-Anvil Apparatus
Tetrahedral Press might be considered a three-
Cluster of
tetrahedral
anvils
dimensional extension of the two dimensional Bridgman anvil
concept. The principle of massive support is still at work in the
tetrahedral press and other multianvil presses, but to a lesser
extent than in Bridgman anvils.
The original tetrahedral press, T. Hall, 1999.
Small tetrahedral anvil press
in ISSP-Tokyo in 2000
Multi-Anvil Apparatus
Cubic Press
Wedge-type, Cubic-Anvil Apparatus in
Tsukuba, Japan
Anvil guide for cubic press, T. Hall
Force [100]
Force [111]
Kumazawa (1977)
Force [111]
Conceptual Diagram of DIA-type
Cubic-Anvil Apparatus
Multi-Anvil Apparatus
• “Large volume” specimens
-1 mm3 to 1cm3
• Adjust and Control
– T and dT/dz
– P and dP/dz
– Stress and Strain State
– Long run duration at stable T-P
– Chemical state (e.g., pO2)
Nomenclature of
High Pressure Apparatus
• Uniaxial:
• Piston-in-cylinder
• Bridgman/Drickamer -->Diamond anvil cell [DAC]
• Belt-type apparatus
• Multiaxial:
• Single stage: force transmitted in one stage to cell assembly
• Tetrahedral-anvil: 4 rams, tetrahedron cell assembly
• Cubic-anvil: 6 rams, cubic cell assembly
• Two-stage: force transmitted in two stages to cell assembly
• 6-8 or MA8: 6 first-stage anvils, driving second-stage of 8 cubes,
compressing cell assembly
• Examples: Split-sphere or split-cylinder apparatus
• Three stage: force transmitted in three stages to cell assembly
• 6-8-2: 6 first-stage anvils, driving second-stage of 8 cubes, driving 2
opposed anvils, compressing cell assembly
Two-stage
Bayreuth Large Volume Multianvil Apparatus
Split-cylinder
Frost et al PEPI (2004)
5000 ton press at Bayerisches Geoinstitut,
Two-stage
Bayreuth
Three-stage
from Endo and Ito (1982)
6/2: Going to megabar
Utsumi et al., 1986; 2004
Current Record
Pmax = 63 GPa
E. Ito (Feb 2004)
Katsura et al (2004)
Paris-Edinburgh Press
Besson et al., 1992
P> 10 GPa
Toroidal anvil arrangement +
Small hydraulic 250 ton press:
~50kg weight (1 ton- commercially
available with the same capacity)
Neutron powder diffraction
Samples: 100 mm3
Small press to fit in a standard hutch
Paris-Edinburgh Press
• Pressure homogeneity as good as in MA
cells
• Pressure homogeneity is far better than on
opposed flat anvil systems which generate
strong biaxial components of stress and
strain
• Quasi-spherical compression of the
sample
High-pressure cells developed in
Russia
Based on Bridgman anvils
1960- lentil-type
P~6 GPA
T~1600°C
HT zone~ 60 cm3 (24 g diamonds per cycle)
Stishovite synthesis (1961)
(P~ 9 GPa, T~1500°C)
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1984- toroid-type
Khvostantsev, 1984
-decreases extrusion of central part of gasket
-large clearence between the anvils at HP
-P in toroidal depression reduces shear
stress in the punch
-ultimate P depends on the working volume
Paris-Edinburgh Press
Gaskets:
Ingredients:
B: Boron from Sigma ... B-3135 Practical grade
R: Resin LY556 from - Italian distributor:
H: Hardener HT972 (same provider as the resin)
For a 3 g pellet:
2.25 g B + 0.59 g R + 0.16 g H (75% B + 19.7% R + 5.3% H in
weight)
(A 3 g pellet corresponds approximately to a cylindrical rod of 1.3 cm2
section times 12 mm length.
These are the original values for the 13 mm Specac pelletter.)
Wilson Crichton, 2005, ESRF
Summary
• There is a permanent progress in PT
ranges reachabel using MA techniques
• Special designes are adapted for specific
purposes
• Progress is based on development of new
superhard materials and invantive designs
• Creativity of individuals has the same
value as more than 200 years ago