SOCIETA ITALIANA
DI
FISICA
RENDICONTI
DELLA
SCUOLA
INTERNAZIONALE
DI
FISICA
"ENRICO
FERMI"
CXLVII
CORSO
a
cura
di R. J.
HEMLEY
e G. L.
CHIAROTTI
Direttori
del
Corso
e di
M.
BERNASCONI
e L.
ULIVI
VARENNA
SUL
LAGO

HEMLEY
and G. L.
CHIAROTTI
Directors
of the
Course
and by
M.
BERNASCONI
and L.
ULIVI
VARENNA
ON
COMO LAKE
VILLA
MONASTERO
3 – 13
July
2001
High
Pressure Phenomena
2002
Ohmsha
AMSTERDAM, OXFORD, TOKYO, WASHINGTON
DC
Copyright
©
2002
by
Societa

1
58603
269 0
(IOS
Press)
ISBN
4 274
90538
1
C3042 (Ohmsha)
Library
of
Congress Catalog Card Number: 2002110641
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G. L.
CHIAROTTI,
M.
BERNASCONI
and L.
ULIVI
-
Preface
pag.
XIX
Gruppo
fotografico
dei
partecipanti
al
Corso
» XXX
STATIC
COMPRESSION:
OVERVIEW
AND
TECHNIQUES
R. J.
HEMLEY
and H. K.
MAO
-
Overview
of
static

3'1. Synchrotron radiation
» 13
3.2.
Polycrystalline X-ray
diffraction
» 14
3.3. Single-crystal X-ray
diffraction
» 15
3.4.
Radial X-ray
diffraction
» 16
3"5.
X-ray
spectroscopy
and
inelastic
scattering
» 16
3'6.
Neutron
diffraction
and
scattering
» 18
3.7. Optical spectroscopy
» 18
3.8. Electrical
and

» 27
4.6.
Pressure
effects
on
biological systems
» 30
4.7.
New
generation
of
high pressure devices
» 30
5.
Conclusions
» 32
VII
VIII
INDICE
T.
YAGI
-
Experimental
overview
of
large-volume
techniques
pag.
41
1.

3.1. Single-stage cubic anvil
» 46
3.2. Double-stage apparatus
» 47
4.
Combination with synchrotron radiation
» 49
5.
Pressure
and
temperature measurements
» 51
6.
Advantages
and
problems
of
large-volume apparatuses
» 52
7.
Current prospects
for
large-volume techniques
» 52
8.
Summary
» 53
R.
BOEHLER,
D.

Aluminum
» 62
6.
Transition metals
» 62
7.
Alkaline-earth metals
» 65
8.
Rare-earth metals
» 65
9.
Noble gases
» 68
J. S.
LOVEDAY
-
Crystallography
at
high
pressure
» 73
1.
Introduction
» 73
2.
Radiation
» 73
3.
Data

Conclusions
» 83
Y. K.
VOHRA
and S. T.
WEIR
-
Designer
diamond
anvils
in
high
pressure
research:
Recent
results
and
future
opportunities
» 87
1.
Introduction
» 87
1.l. Advent
of
designer
diamond technology
» 88
INDICE
IX

» 93
3.3. Four-probe electrical resistance measurements
on
single wall carbon
nanotubes samples using designer diamond anvils
» 97
3.4.
Four-probe electrical resistance measurements
on
beryllium using
de-
signer
diamond anvils
» 100
3'5. Magnetic susceptibility measurements with designer loop anvils
» 102
Future opportunities
» 104
4.1. Next generation
of
designer diamond anvils: Multitasking designer
diamond anvils
» 104
DYNAMIC
COMPRESSION: OVERVIEW
AND
TECHNIQUES
W. J.
NELLIS
—

Elastic-plastic
flow and
material strength
2.5.2.
Shock-induced phase transitions
2.6.
Release
of
shock pressure
by
sound waves
2.6.1.
Speed-of-sound measurements
2.6.2.
Gruneisen parameter
and
phase transitions
2.7.
Electrical resistivity
2.8.
Raman spectroscopy
2.9.
Flash X-ray
diffraction
2.10.
Computer simulations
3.
Synthesis
and
recovery

109
110
111
112
115
116
117
117
118
118
119
119
120
120
120
121
121
122
123
123
123
123
123
124
124
124
X
INDICE
V. E.
FORTOV

4.3. Electrical conductivity
» 139
4.4.
Adiabatic expansion
» 141
5.
Conclusions
» 144
THEORY
AND
FUNDAMENTALS
N. W.
ASHCROFT
—
Condensed matter
at
higher densities
» 151
1.
Introduction
» 151
2.
Nuclei
and
electrons: formulating
the
problem
at
variable volume
» 154

role
of
pressure
» 172
8.
Pair-correlation,
the
Percus argument,
and
liquids
at
high
pressure
» 176
9.
Hydrogen
at
high pressure
» 179
10.
Near ground
states
of
dense hydrogen
» 181
11.
Electronic instability
and
pairing
» 187

» 201
2.5.
First-principles
MD at
constant pressure
» 202
2.6.
Empirical potentials
from
first-principles
simulations
» 203
3.
Applications
» 204
3.1. Silicon
» 204
3.2.
Carbon
» 205
3.3. Hydrogen
» 205
3.4. Oxygen
» 207
3.5. Carbon oxides
» 207
INDICE
XI
3.6.
Hydrocarbons pag.

G.
STEINLE-NEUMANN
and L.
STIXRUDE
—
Importance
of
magnetism
in
phase
stability,
equations
of
state,
and
elasticity
» 215
1.
Magnetism
» 215
1.1. Itinerant magnetism
» 217
1.2.
Mott insulators
» 219
1.2.1. LDA+U
» 219
1.2.2.
Self-interaction corrections
» 221

Fe » 224
3.2.2.
FeO and CoO » 229
4.
Conclusions
» 235
J P.
POIRIER
—
Rheology:
Elasticity
and
viscosity
at
high
pressure
» 239
1.
Introduction
» 239
2.
Equations
of
state
» 241
3.
Viscosity
of
solids
» 244

Lithium
» 264
6.
Sodium
» 266
7.
Concluding remarks
» 268
XII
INDICE
V. V.
STRUZHKIN,
E.
GREGORYANZ,
H. K.
MAO,
R. J.
HEMLEY
and Y. A.
TIMOFEEV
— New
methods
for
investigating
superconductivity
at
very
high
pressures
pag.

MgB2
and
phonon-assisted electronic topological transition
» 291
7.
Conclusions
» 293
A. F.
GONCHAROV,
E.
GREGORYANZ,
V. V.
STRUZHKIN,
R. J.
HEMLEY,
H. K.
MAO,
N.
BOCTOR
and E.
HUANG
-
Raman
scattering
of
metals
to
very high
pressures
» 297

2
and ETT » 308
4.
Conclusions
» 310
SIMPLE
MOLECULAR
SYSTEMS
W. J.
NELLIS
—
Shock
compression
of
hydrogen
and
other
small
molecules
. » 317
1.
Introduction
» 317
2.
Finite temperatures
» 319
3.
Minimum metallic conductivity: hydrogen
» 320
3.1. Experiment

metallic conductivity: oxygen
and
nitrogen
» 328
6.
Proton conductivity: water
» 331
7.
Hydrocarbons: chemical decomposition
» 331
INDICE
XIII
L.
ULIVI
—
Quantitative
spectroscopy
of
simple
molecular
crystals
under
pressure
pag.
337
1.
Introduction
» 337
1"1.
Molecular crystals

» 342
4.2.
Stability
of
e-N
2
and
C-N
2
» 344
4.3.
Vibrational coupling
» 344
5.
Oxygen
» 345
5.1. Magnetism
» 345
5.2.
a-S
transition
» 348
5.3. Molecular pairing
» 349
6.
Conclusive remarks
» 352
J. S.
LOVEDAY
—

Disorder
in ice VII » 362
4.3.
Beyond
ice X » 362
5.
Other ices
» 363
51.
Ammonia
» 363
5'2.
Hydrogen sulphide
» 363
6.
Hydroxyl H-bonds
» 364
6.1.
Alkali
hydroxides
» 364
6.2.
Brucite-structured hydroxides
» 364
7.
CIathrate
hydrates
and
other water-gas mixtures
» 365

[2 + 2]
Cycloadditions
» 377
2.1.2.
[4 + 2]
Cycloadditions
» 378
2.1.3. 1,3-Dipolar cycloaddition
» 382
2.1.4.
Ene
reactions
» 385
2.2.
Michael
and
related reactions
» 385
2.2.1.
Nitroaldol reaction (also called Henry reaction)
» 385
2.2.2.
Knoevenagel reactions
» 385
2.2.3.
Mannich
reactions
» 385
2.3. lonogenic reactions
» 387

reactions
» 391
3.
Conclusions
» 391
G.
JENNER
—
Mechanistic studies
of
organic reactions
by
high pressure kinetics
» 395
1.
Introduction
» 395
2.
Determination
of
mechanisms
» 398
3.
Conclusions
» 410
R.
WINTER
-
High
pressure

additives
» 434
2.6.
Kinetics
of
phase transformations
in
lipid systems
» 438
3.
Pressure
effects
on
protein structure
» 440
3.1. Experimental techniques
» 441
3.2.
Equilibrium studies
of
protein denaturation
» 442
3.3. Kinetic studies
of the
un/refolding reaction
of
proteins
» 446
4.
Exploitation

3.
Kinetics
» 458
4.
Chemical reactions involving aromatic molecules
» 460
4.1.
Benzene
» 461
4.2.
Furan
» 463
4.3.
Thiophene
» 465
4.4.
Styrene
» 465
4.5.
Conclusions
» 465
5.
Chemical reactions
in
crystals
of
very simple molecules
» 466
5.1. Nitriles
» 466

The
emergence
of
high pressure solid
state
science
» 478
3.
"Windowed" experiments
for in
situ studies
of
high pressure phases
and
phase transitions
» 482
4.
Opportunities
for
high pressure solid
state
chemistry
» 482
5.
Thermodynamics,
and
practical considerations
for
high pressure-high
tem-

O,
and
LiSi
. . . . » 492
7.1.
Ge
3
N
4
-Si
3
N
4
spinels
» 492
7.2.
Synthesis
of
icosahedral borides
in the
B
6
O-B
6
N system
» 497
7.3. Synthesis
of
lithium monosilicide,
LiSi

polyamorphism: general considerations
» 520
5.
Liquid-liquid phase transitions
and the
"two-state"
model
to
interpret melt-
ing
curve maxima
» 526
XVI
INDICE
6.
The
"two-state"
model, liquid-liquid
transitions,
and
extension
to
other
sys-
tems pag.
529
7.
The
relationship with glassy
state

the
effects
of the
compositional variable
and the
evolution
towards "normal"
liquid-liquid
immiscibility
» 539
10.
Summary
» 541
A. K.
ARORA
—
Pressure-induced
amorphization
» 545
1.
Introduction
» 545
2. Ice » 546
3.
Quartz
and
other polymorphs
» 549
4.
Other systems

studies
of
carbon
nanotubes:
Pristine
and
iodine-doped
single-walled
bundles
» 567
1.
Introduction
» 567
2.
Structure
and
symmetry, electronic,
and
vibrational properties
» 568
3.
Pressure dependence
of the
Raman bands
in
pristine SWNT bundles
» 572
4.
Iodine-doped SWNT bundles
» 576

a
rock
or a
cloud
of
gas?
» 588
3.
What
are
planets made
of? » 588
4.
"Rocks", "ices"
and
"gases"
» 589
5.
What
are the
pressures inside planets?
» 591
6. How do we figure out the
behavior
of
materials
at
high
pressure?
» 592

7.6.
Surface
thermodynamic
and
chemical
state
pag.
595
7.7.
Intrinsic magnetic
field and
paleomagnetism
» 596
7.8. Electromagnetic response
» 596
8.
The
gravity
field and
moments
of
inertia
» 596
9.
Observed heat
flows » 599
10.
Expected heat
flows » 599
101. Radioactivity

fields are
observed?
» 602
14.
What
is the
geometry
of
large
fields? » 602
15.
Where
do
magnetic
fields
come
from?
» 604
16.
Why do
some planets have dynamos
while
others
do
not?
» 605
17.
Concluding comments
» 605
W. J.

—
Earth
materials
at
high
pressures
and
temperatures:
The
case
of the
Earth's
core
» 619
1.
Introduction
» 619
2.
Composition
of the
outer core
» 620
3.
Reactions
at the
core-mantle boundary
» 621
4.
Viscosity
of the

R.
BOEHLER,
L.
CHUDINOVSKIKH
and V.
HILLGREN
—
Earth's core
and
lower
mantle:
Phase
behavior
melting,
and
chemical
interactions
» 627
1.
Introduction
» 627
2.
Seismic velocity discontinuities
in the
Earth's
mantle
» 628
2.1.
Melting temperatures
of

» 635
2.5.
Melting depression
of
iron
by
light elements
» 635
3. The
core-mantle boundary
» 636
3.1. Temperature
» 636
4.
Chemical interaction between
the
core
and the
mantle
» 637
T.
YAGI
—
Behavior
of
Earth
materials
under
deep
mantle

3.3. Garnet
» 650
3.4. Dense
silicate
structure:
Perovskite
» 651
4.
Summary
» 654
Indice
analitico
» 657
Elenco
dei
partecipanti
» 669
Preface
Emergence
of
modern
high
pressure
science
In
many respects,
the
science
of
materials

exploring
the
nature
of
materials
was for
years
unfulfilled
for a
number
of
reasons:
the
accessible pressure-temperature conditions were
too
modest
to
cause significant changes
in
many materials, samples under high pressure could
not be
subjected
to
thorough
analyses,
or
theory
was not
sufficiently
well

the
last
decade. High pressure
science
has
experienced tremendous growth, particularly
in the
last
few
years. With
recent
developments
in
static
and
dynamic compression techniques, extreme pressure
and
temperature conditions
can now be
produced
and
carefully
controlled over
a
wide
range. Moreover,
a new
generation
of
analytical probes, many based

understanding
of
materials
as a
whole
and
guiding subsequent experimental
work
with
new
predictions.
It was for
this reason
that
this course
on
high pressure science
was
held
at the
Inter-
national School
of
Physics "Enrico Fermi"
in
July 2001. Though presented
in a
physics
forum,
the

as
well
as
biology.
The
highly interdisciplinary character
of the field was
central
to the
organization
of the
School, though
the
sheer breadth
of the field
meant
that
many topics could
be
treated
in
only
a
cursory
fashion
while
others
were
examined
more

and
theoretical)
for
investigation
of
matter
at
high pressure conditions were
presented, together with general overviews
of
applications.
The
second type
was
devoted
to
examining special topics.
The
topics
were
interpersed throughout
the 10
days
of the
School
in 47
lectures
and
seminars;
the

and
Biology
VII.
Liquids, Glasses,
and
Nanostructures
VIII.
Earth
and
Planetary Science
Overview
of the
volume
Accelerating
advances
in
static
compression techniques, specifically, those based
on
the
diamond-anvil cell, have been
one of the
major reasons
for the
explosive growth
in
the
high pressure
field. The first
section begins with

up to
multimegabar
pressures
(>
3Mbar
or > 300
GPa). They then
briefly
discuss several applications
that
comple-
ment
studies presented
later
in the
volume; these include dense hydrogen,
new
materials,
dense
oxides,
and
microbial activity. These techniques
and
applications
can be
com-
pared with those based
on
so-called large volume high pressure devices.
As

various large volume devices
for in
situ studies with synchrotron
radiation. Though
the
pressure range
of the
"large volume" devices (multianvil presses)
PREFACE
XXI
is
significantly lower
than
that
of
conventional diamond-anvil cells, pressures
as
high
as
50
GPa
have been reached with sintered diamond.
As
discussed
by
Hemley
and
Mao,
a
particularly exciting current development

and its
applications
to
high
P-T
phase diagrams. Introducing
an
example
of the
technique (see also Hemley
and
Mao),
the
lecture reviews melting
ex-
periments
and
phase diagrams
and the use of
various criteria
to
identify
melting. Exam-
ples
of
materials studied include alkali halides, simple metals, transition metals, alkaline
earths, rare earths,
and
noble gases.
The

complementary nature
of the
two.
He
also provides
a
brief overview
of
powder diffraction versus single-crystal diffraction, current
efforts
to
expand
both
the
accuracy
and P-T
ranges
of
these techniques,
and
widely
used methods
of
refinement
techniques used
to
determine atomic positions.
Vohra
and
Weir

concepts
for
the
next generation
of
designer diamond anvils with multi-tasking capabilities, including
joule
heating, temperature measurements, diamond strain measurements,
and
integrated
electrical
transport
and
magnetic measurements
that
complement
the
large
anvil
effort
for
a new
generation
of
"large
and
smart"
anvil high pressure devices (see Hemley
and
Mao).

state,
which have been used
in
turn
for
developing
static
high pressure scales.
New
techniques allow accurate determination
of
shock temper-
atures, shock
profiles,
elastic-plastic
flow,
sound speeds, electrical resistivity,
and
X-ray
diffraction.
Recent applications include materials synthesized
and
recovered
from
high
dynamic
pressures, such
as
nanostructures,
films,

the
authors
then summarize
properties
of
plasmas
under extreme
conditions, including equations
of
state,
optical properties, electrical conductivity,
and
behavior
on
adiabatic expansion. Representative examples
of
recent studies
of
elemental
materials
provide
a
meeting ground
for
static
compression
and
lower
temperature
shock

variety
of
theoretical approaches used
to un-
derstand materials
at
high densities.
Ashcroft
begins with
a
thorough overview
of
funda-
mental theory, beginning with
the
formulation
of the
problem
of the
behavior
of
nuclei
and
electrons with variable volume,
the
role
of
pressure
in
controlling

correlation.
Specific
applications
include
hydrogen
at
high pressure,
and the
possibility
of
unusual
effects
of
re-entrant melting
and
liquid-like
phases.
Many
theoretical studies require large scale computational techniques.
Scandolo
introduces
a
particularly important method,
first-principles
molecular dynam-
ics
—the Car-Parrinello method,
which
was first
introduced

simple molecular compounds,
and
metals
are
presented,
followed
by
perspectives
on
future
directions.
Complementing
the
above theoretical lectures, Cohen
et al.
examine
new findings
regarding
the
role
of
magnetism
in
affecting
phase
stability,
equations
of
state,
and

discussed
in
later
lectures)
as
well
as
from
a
fundamental point
of
view,
in
view
of
recent
experimental
findings
(see Goncharov
et
al).
High
pressure studies
of
rheology, includ-
ing
both elasticity
and
viscosity,
are

in
Earth science (see Boehler
et
al.).
The
above topics lead naturally
to
Section
IV,
which
concerns experimental stud-
ies of
metals
and
superconductors under pressure.
One of the
surprises
in
recent
work
in
this area
has
been
the
structural complexity
of
simple metals
at
high pressure.

together
with
first-principles
methods discussed above
are
leading
to new
insight
and
systematics. Examples include
Cs, Rb, and Li; the
latter
has
been predicted
to
undergo symmetry breaking transitions with possible parallels
to
dense hydrogen (see
Ashcroft).
In
addition
to
crystallographic studies
of
metals, breakthroughs
in two
additional
areas have
led to the
discovery

of
these developments,
focusing
primarily
on new
magnetic susceptibility techniques
that
can now be
used
to
multi-
megabar pressures (e.g.,
> 200
GPa).
The
lecture summarizes
the
evolution
of
these
methods, culminating
in the
development
of the
double modulation technique
that
is
currently used
at the
very highest

review
these developments, including details
of the
experimental tech-
nique
and
applications
to Fe and Fe
alloys,
Re, and
MgB2
(also discussed
by
Struzhkin
et
al.).
Historically, simple molecular systems have been
a
particularly important class
of
materials
for
high
pressure
investigations.
With
their
very high
compressibilities,
solid

of
by far the
most interest since
the
earliest calculations
of
predicted pressure-induced
metallization
for the
solid.
Nellis
presents
an
overview
of
recent dynamic compression
studies
of fluid
hydrogen
and
related
molecular systems, including
the
recent observations
of
minimum
metallic
conductivity
in fluid
hydrogen

these pressures
in the low
temperature solid (see Hemley
and
Mao). Recent evidence
is
presented
for
protonic conductivity
in
water
and
chemical
decomposition
of
hydrocarbons, both
of
which
have been addressed
in
static
compression
experiments.
The
following
two
lectures examine simple molecular systems
from
the
standpoint

information
that
can
be
obtained
from
spectroscopic studies
has
been demonstrated. This includes
the
mag-
netism
in O
2
,
which
is
unique
for a
simple molecular system,
and the
proposed pairing
of
the
molecules
in
high pressure phases. Loveday's second lecture presents
an
overview
of

the
development
of
high pressure neutron
diffraction
techniques,
as
well
as
vibrational
spectroscopic methods
at
higher (i.e., megabar) pressures.
Continuing
the
theme
of
molecular systems, Section
VI
focuses
on the new
insight
XXIV
PREFACE
high pressure
studies
have provided
both
for
synthetic organic chemistry

kinetics
can be
used
to
identify
these
and
other mechanisms. Winter provides
an
overview
of the
high pressure
effects
in
molecular
biophysics,
which
together with other related studies
of
soft
matter constitute another
growing
research area.
After
an
introduction
to
lipid mesophases
and
model biomembrane

to
address
the
protein folding problem.
There
are
impli-
cations
of
these types
of
investigations
in
biotechnology
and
molecular biology, including
the
behavior
of
extremophiles (see Hemley
and
Mao),
food
science,
and
understanding
fundamental
structure-function relationships
in
biomolecules

electronic
states
under pressure,
and a
competition between thermal
and
photochemical reactions distinguish these reactions
from
the
lower pressure solution
chemistry described above. Infrared spectroscopy
is a
particularly
useful
technique
for
such
study,
as
shown
by
examples
of
chemical reactions involving aromatic molecules,
alkenes,
and
other simple molecules, including their kinetics.
McMillan
focuses
on

erful
window
on
reacting materials. This
is
demonstrated
by
recent studies
of
molecular
materials, including
van der
Waals compounds, CO
2
,
and
N
2
O, nitride spinels, icasohe-
dral B
6
O,
and
LiSi.
There
are
important
new
opportunities, including
the

morphism
—the evidence
for
transformations
in the
liquid
state
analogous
to
those
found
in
solids.
The
best examples appear
to be
from
supercooled (i.e.,
metastable
liquids),
but
recent results point
to
transitions
in
liquids within their thermodynamic stability
fields.
The
thermodynamic basis
for the

other materials.
A
metastable transition
that
is
clearly
affected
by the
inhibited kinetics
of
equilibrium
PREFACE
XXV
phase
transitions
and
therefore
temperature,
pressure-induced
amorphization
can
occur
as a
result
of
pressure-induced decomposition (chemical reactions). Finally,
the
high
pressure properties
of

and
iodine-doped bundles.
A
series
of
lectures
on
Earth
and
planetary interiors
are
collected
in the final
section.
The
section begins with
a
broad introduction
to the field of
planetary interiors
as a
whole
by
Stevenson.
The
interior structure, composition,
and
dynamics
of the
planets contain

materials include rocks (minerals), ices (molecular systems),
and
gases. Approximate
methods
can be
used
to
determine
the
pressure
as a
function
of
depth within planets (the
pressures
are
known with high accuracy
if
seismological measurements
can be
performed).
External measurements
that
reveal information about internal
state
and
past
history
of
the

can
give
rise
to the
planet's
large
and
turbulent magnetic
field.
These
interiors
may be
compared
with
those
of the icy
giant planets (Uranus
and
Neptune),
which
are
composed
of
water
and
water-rich molecular mixtures.
The final
three lectures summarize
the
great

of the
inner
core.
Boehler
et al.
examine materials
of the
Earth's
core
and
lower mantle,
focusing
on
phase behavior, melting,
and
chemical reactions
for
major phases.
The
review shows
how
differences
in the
determinations
of
melting temperature
of
iron give rise
to the
rather

deep mantle materials
is
also reviewed
in
Yagi's second lecture.
Beginning
with
an
overview
of the
structure
of the
mantle,
he
reviews
the
diversity
of
techniques including opposed anvil, multianvil,
and
laser-heated
diamond-anvil cells.
These
are
supplemented with
in
situ X-ray measurements discussed elsewhere
as
well
as