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Materials under pressure
Topics: (in no particular order)
Methods of generating high pressures
Synthesis under pressure
Properties under pressure
Ram Seshadri
Materials Department, and
Department of Chemistry and Biochemistry
Materials Research Laboratory
University of California, Santa Barbara CA 93106
http://www.mrl.ucsb.edu/~seshadri +++ [email protected]
Materials 218 Class 1
Materials under pressure, why care?
Materials 218 Class 1
Materials under pressure, the pioneer: Percy Bridgeman
Percy Williams Bridgman
(21 April 1882 – 20 August 1961)
1946 Nobel Prize in Physics
wikimedia
A modern system in the Huppertz lab at the University of Innsbruck
Materials 218 Class 1
Materials under pressure, the pioneer: Percy Bridgeman
Compressibility of ether, and Cs (from the Nobel lecture).
10,000 kg cm–2 = 0.981 GPa ≈ 1 GPa = 10 kbar
Materials 218 Class 1
Bridgman speaks of 10 GPa pressures being
attainable in 1946.
Materials under pressure, the pioneer: Percy Bridgeman
Volume compression of some elements. Note the
phase transitions (from the Nobel lecture).
Materials 218 Class 1
Materials under pressure, the pioneer: Percy Bridgeman
Electrical resistivity of some elements (from the
Nobel lecture)
Materials 218 Class 1
Materials under pressure: Ice etc.
The p–T diagram of H2O (D2O) and a new phase (Ice-XII, 0.2 Gpa to 0.6 GPa)
Ti–Zr pressure cell, with external Ar pressure at a neutron diffractometer.
Lobban, Finney, Kuhs, Nature 391 (1998) 268–270.
Materials 218 Class 1
Materials under pressure: An example of synthesis under pressure
Bi2MnNiO6, a ferromagnetic, ferroelectric (?) double perovskite:
“Bulk sample of Bi2NiMnO6 was prepared from a stoichiometric mixture of
Bi2O3, NiO, and MnO2. The starting material was charged into a gold capsule,
treated at 6 GPa and 800 °C for 30 min in a cubic anvil-type high-pressure
apparatus. Then it was slowly cooled to the room temperature for 4-50 h before
releasing the pressure.”
Azuma, Takata, Saito, Ishiwata, Shimakawa, Takano, Designed Ferromagnetic, Ferroelectric
Bi2NiMnO6, J. Am. Chem. Soc. 127 (2005) 8889-8892.
Materials 218 Class 1
Materials under pressure: An example of synthesis under pressure
Bi2MnNiO6, a ferromagnetic, ferroelectric (?) double perovskite:
Space group C2 (can support a polarization)
Azuma, Takata, Saito, Ishiwata, Shimakawa, Takano, Designed Ferromagnetic, Ferroelectric
Bi2NiMnO6, J. Am. Chem. Soc. 127 (2005) 8889-8892.
Materials 218 Class 1
Materials under pressure: In the earth
MgSiO3 (Mg2Si2O6, pyroxene):
ambient
pressure,
enstatite
high-pressure,
perovskite/
Bridgmanite
ultra-highpressure, postperovskite/
CaIrO3 structure
(above 100 GPa)
Materials 218 Class 1
Materials under pressure: Bridgmanite
Science 346 (2014) 1100–1102.
The Tenham L6 chondrite:
“MgSiO3-perovskite is now called
bridgmanite. The associated phase
assemblage constrains peak shock
conditions to ~24 gigapascals and 2300
kelvin. The discovery concludes a half
century of efforts to find, identify, and
characterize a natural specimen of this
important mineral.”
Materials 218 Class 1
Materials under pressure: Understanding phases under pressure
Grochala, Hoffmann, Feng, Ashcroft, Angew.
Chem. Int. Edn. 46 (2007) 3620–3642.
Materials 218 Class 1
“We will discuss in detail an
overlapping hierarchy of responses
to increased density: a) squeezing
out van der Waals space (for
molecular crystals); b) increasing
coordination; c) decreasing the
length of covalent bonds and the
size of anions; and d) in an extreme
regime, moving electrons off atoms
and generating new modes of
correlation.”
Materials under pressure: Understanding phases under pressure
Rules:
1. Van der Waals space is most easily compressed
2. Ionic and covalent structures, be they molecular or extended, respond to
pressure by increasing coordination
3. Increased coordination is achieved relatively easily through donor–
acceptor bonding, which shades over into multicenter bonding. Such
multicenter bonding, electron-rich or electron-poor, is a mechanism for
compactification (hence, a response to elevated pressure) for elements
across the Periodic Table
4. Orbital-symmetry considerations will affect the chance that a highpressure product survives return to metastability in the ambient-pressure
world.
5. In ionic crystals, the anions are more compressible than the cations;
therefore, the coordination number (especially that of the cations)
increases at high pressure
Grochala, Hoffmann, Feng, Ashcroft, Angew.
Chem. Int. Edn. 46 (2007) 3620–3642.
Materials 218 Class 1
Materials under pressure: Understanding phases under pressure
Rules (contd.):
6. All materials become metallic under sufficiently high pressure
7. Thinking about Peierls distortions (their enhancement and suppression) is
helpful in understanding symmetrization (or its absence) in solids under
high pressure
8. Under extremely high pressure, electrons may move off atoms, and new
“non-nucleocentric” bonding schemes need to be devised
9. Close packing is the way, for a while. But keep an open mind—still denser
packing may be achieved through electronic disproportionation and
through nonclassical deformation of spherical electron densities.
10. Pressure may cause the occupation of orbitals that a chemist would not
normally think are involved
Grochala, Hoffmann, Feng, Ashcroft, Angew.
Chem. Int. Edn. 46 (2007) 3620–3642.
Materials 218 Class 1
Materials under pressure
The superconducting elements (bulk, ambient pressure)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
H
18
He
Li
Be
B
C
N
O
F
Ne
Na
Mg
1
2
3
4
5
6
7
8
9
10
Al
Si
P
S
Cl
Ar
K
Ca
Sc
Ti
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Ga
Ge
As
Se
Br
Kr
Rb
Sr
Y
Zr
Nb
Mo
Tc
Ru
Rh
Pd
Ag
Cd
In
Sn
Sb
Te
I
Xe
Cs
Ba
La
Hf
Ta
W
Re
Os
Ir
Pt
Au
Hg
Tl
Pb
Bi
Po
At
Rn
Fr
Ra
Ac
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
La
Ce
Pr
Nd
Pm
Sm
Er
Gd
Tb
Dy
Ho
Eu
Tm
Yb
Lu
Ac
Th
Pa
U
Np
Pu
Am
Cm
Bk
Cf
Es
Fm
Md
No
Lr
CRC Handbook of Physics and Chemistry [http://www.hbcpnetbase.com/]
Materials 218 Class 1
Materials under pressure
The magnetic(ally ordered) elements [Ferromagnetic or antiferromagnetic]
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
H
18
He
Li
Be
B
C
N
O
F
Ne
Na
Mg
1
2
3
4
5
6
7
8
9
10
Al
Si
P
S
Cl
Ar
K
Ca
Sc
Ti
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Ga
Ge
As
Se
Br
Kr
Rb
Sr
Y
Zr
Nb
Mo
Tc
Ru
Rh
Pd
Ag
Cd
In
Sn
Sb
Te
I
Cs
Ba
La
Hf
Ta
W
Re
Os
Ir
Pt
Au
Hg
Tl
Pb
Bi
Po
At
Fr
Ra
Ac
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
La
Ce
Pr
Nd
Pm
Sm
Er
Gd
Tb
Dy
Ho
Eu
Tm
Yb
Lu
Ac
Th
Pa
U
Np
Pu
Am
Cm
Bk
Cf
Es
Fm
Md
No
Lr
Magnetism and superconductivity are largely incompatible
CRC Handbook of Physics and Chemistry [http://www.hbcpnetbase.com/]
Materials 218 Class 1
Fe
ferromagnet
Xe
Mn
antiferro
Rn
Tm
mixed
Materials under pressure
Some (new) superconducting elements (under pressure)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
H
18
He
Li
Be
B
C
N
O
F
Ne
Na
Mg
1
2
3
4
5
6
7
8
9
10
Al
Si
P
S
Cl
Ar
K
Ca
Sc
Ti
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Ga
Ge
As
Se
Br
Kr
Rb
Sr
Y
Zr
Nb
Mo
Tc
Ru
Rh
Pd
Ag
Cd
In
Sn
Sb
Te
I
Xe
Cs
Ba
La
Hf
Ta
W
Re
Os
Ir
Pt
Au
Hg
Tl
Pb
Bi
Po
At
Rn
Fr
Ra
Ac
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
La
Ce
Pr
Nd
Pm
Sm
Er
Gd
Tb
Dy
Ho
Eu
Tm
Yb
Lu
Ac
Th
Pa
U
Np
Pu
Am
Cm
Bk
Cf
Es
Fm
Md
No
Lr
Pressure can drastically change electronic structure (for eg. Ba behaves like a transition metal)
Buzea, Robbie, Supercond. Sci. Technol. 18 (2005) R1-R8.
Materials 218 Class 1
impetus mutat res
Materials under pressure: The diamond anvil cell
Invented at NBS (now NIST):
Weir, Lippincott, Van Valkenburg, Bunting, J. Res. Natl. Bur. Stand. 63A (1959) 55–62;
Forman, Piermarini, Barnett, Block, Science 176 (1972) 284–285.
Materials 218 Class 1
Materials under pressure: The diamond anvil cell
The modern DAC
Akella, Science and Technology Review of the LLNL, March 1996, pages 17–26.
Materials 218 Class 1
Materials under pressure: The diamond anvil cell
Example of DAC research: MgSiO3 at 118 GPa and 300 K.
Oganov, Ono, Nature 430 (2004) 445–448.
Materials 218 Class 1
Materials under pressure: The Hugoniot locus (locus of single-shocked states)
Shock compression increases p and T at the same time: The eg. of Ta
Li, Zhou, Li, Wu, Cai, Dai, Rev. Sci. Instr. 83 (2012) 053902(1–7).
Materials 218 Class 1
Materials under pressure: The monster 500 TW experiment
“The National Ignition Facility is the premier high energy density science facility in
the world … major focus of NIF is a national effort to demonstrate ignition and
thermonuclear burn in the laboratory … a variety of experiments to study matter at
the extremes, including studies of material properties… A NIF experimental
platform typically consists of an integrated laser, hohlraum, and diagnostic suite
capable of providing well-characterized pressure, temperature, implosion, or other
environments. Particular samples are then placed within the hohlraum and
studied.”
Materials 218 Class 1
Materials under pressure: The monster experiment
Smith et al. Nature 511 (2014) 330–333.
Materials 218 Class 1
Materials under pressure
“Top, the temporally resolved velocity
interferometry record.
Bottom, derived free-surface velocity ufs
versus time.
The target (inset) consists of a gold
cylinder (hohlraum) 6 mm in diameter by
11 mm long, inside which the 351-nm
wavelength laser light (purple beams) is
converted to X-ray energy that is
absorbed by the diamond sample
attached to the side of the hohlraum.
The X-rays ablate and ramp-compress
the sample …”
Smith et al. Nature 511 (2014) 330–333.
Materials 218 Class 1
Materials under pressure
Hugoniots for compression of
diamond to 5 TPa
Smith et al. Nature 511 (2014) 330–333.
Materials 218 Class 1

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