Materials 218 Class 1

Materials under pressure

Ram Seshadri

Materials Department, andDepartment of Chemistry and BiochemistryMaterials Research LaboratoryUniversity of California, Santa Barbara CA 93106http://www.mrl.ucsb.edu/~seshadri +++ seshadri@mrl.ucsb.edu

Topics: (in no particular order)

Methods of generating high pressures

Synthesis under pressure

Properties under pressure

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

10,000 kg cm–2 = 0.981 GPa ≈ 1 GPa = 10 kbar

Bridgman speaks of 10 GPa pressures being attainable in 1946.

Compressibility of ether, and Cs (from the Nobel lecture).

Materials 218 Class 1

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 pressureBi2MnNiO6, 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 pressureBi2MnNiO6, a ferromagnetic, ferroelectric (?) double perovskite:

Azuma, Takata, Saito, Ishiwata, Shimakawa, Takano, Designed Ferromagnetic, Ferroelectric Bi2NiMnO6, J. Am. Chem. Soc. 127 (2005) 8889-8892.

Space group C2 (can support a polarization)

Materials 218 Class 1

Materials under pressure: In the earth

MgSiO3 (Mg2Si2O6, pyroxene):

ambient pressure,enstatite

high-pressure, perovskite/ Bridgmanite

ultra-high-pressure, post-perovskite/ 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.

“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 218 Class 1

Materials under pressure: Understanding phases under pressure

Grochala, Hoffmann, Feng, Ashcroft, Angew. Chem. Int. Edn. 46 (2007) 3620–3642.

Rules:1. Van der Waals space is most easily compressed2. Ionic and covalent structures, be they molecular or extended,

respond to pressure by increasing coordination3. 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 high-pressure 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

Materials 218 Class 1

Materials under pressure: Understanding phases under pressure

Grochala, Hoffmann, Feng, Ashcroft, Angew. Chem. Int. Edn. 46 (2007) 3620–3642.

Rules (contd.):

6. All materials become metallic under sufficiently high pressure7. 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

Materials 218 Class 1

101 2 3 4 5 6 7 8 9

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

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

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Na Mg Al Si P S Cl Ar

Li Be B C N O F Ne

H He

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

The superconducting elements (bulk, ambient pressure)

CRC Handbook of Physics and Chemistry [http://www.hbcpnetbase.com/]

Materials under pressure

Materials 218 Class 1

101 2 3 4 5 6 7 8 9

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

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

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Na Mg Al Si P S Cl Ar

Li Be B C N O F Ne

H He

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

The magnetic(ally ordered) elements [Ferromagnetic or antiferromagnetic]

CRC Handbook of Physics and Chemistry [http://www.hbcpnetbase.com/]

Mn

Fe

Tm

ferromagnet

antiferro

mixed

Magnetism and superconductivity are largely incompatible

Materials under pressure

Materials 218 Class 1

101 2 3 4 5 6 7 8 9 Al

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

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

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14

Na Mg Si P S Cl Ar

Li Be B C N O F Ne

H He

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Some (new) superconducting elements (under pressure)

Buzea, Robbie, Supercond. Sci. Technol. 18 (2005) R1-R8.impetus mutat res

Pressure can drastically change electronic structure (for eg. Ba behaves like a transition metal)

Materials under pressure

Materials 218 Class 1

Materials under pressure: The diamond anvil cell

Weir, Lippincott, Van Valkenburg, Bunting, J. Res. Natl. Bur. Stand. 63A (1959) 55–62; Forman, Piermarini, Barnett, Block, Science 176 (1972) 284–285.

Invented at NBS (now NIST):

Materials 218 Class 1

Materials under pressure: The diamond anvil cell

Akella, Science and Technology Review of the LLNL, March 1996, pages 17–26.

The modern DAC

Materials 218 Class 1

Materials under pressure: The diamond anvil cell

Oganov, Ono, Nature 430 (2004) 445–448.

Example of DAC research: MgSiO3 at 118 GPa and 300 K.

Materials 218 Class 1

Materials under pressure: The Hugoniot locus (locus of single-shocked states)

Li, Zhou, Li, Wu, Cai, Dai, Rev. Sci. Instr. 83 (2012) 053902(1–7).

Shock compression increases p and T at the same time: The eg. of Ta

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

Smith et al. Nature 511 (2014) 330–333.

“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 …”

Materials 218 Class 1

Materials under pressure

Smith et al. Nature 511 (2014) 330–333.

Hugoniots for compression of diamond to 5 TPa