Transformations of Phosphorus under Pressure from Simple Cubic to Simple Hexagonal Structures via Incommensurately Modulations: Electronic Origin

The lighter group-V element phosphorus forms the As-type (hR2) structure under pressure, above 5 GPa, and at 10 GPa transforms to the simple cubic structure (cP1), similar to arsenic. Despite its low packing density, the simple cubic structure is stable in phosphorus over a very wide pressure range up to 103 GPa. On further pressure increase, the simple cubic structure transforms into a simple hexagonal structure (hP1) via a complex phase that was solved recently as incommensurately modulated. Structural transformations of phosphorus are connected with the changes of physical properties. Above 5 GPa phosphorus shows superconductivity with Tc reaching ~9.5 K at 32 GPa. The crystal structures and properties of high-pressure phases for phosphorus are discussed within the model of the Fermi sphere and Brillouin zone interactions.

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Structural simplicity and complexity of compressed calcium: electronic origin

Acta Crystallographica Section B Structural Science Crystal Engineering and Materials ◽

10.1107/s2052520614002704 ◽

2014 ◽

Vol 70 (3) ◽

pp. 423-428 ◽

Cited By ~ 9

Author(s):

Valentina F. Degtyareva

Keyword(s):

Valence Electron ◽

Interaction Model ◽

Outer Core ◽

Electron Number ◽

Fermi Sphere ◽

Simple Cubic ◽

Valence Electrons ◽

Cubic Structure ◽

Structural Simplicity ◽

Tetragonal Cell

A simple cubic structure with one atom in the unit cell found in compressed calcium is counterintuitive to the traditional view of a tendency towards densely packed structures with an increase in pressure. To understand this unusual transformation it is necessary to assume electron transfer from the outer core band to the valence band, and an increase of valence electron number for calcium from 2 to ∼ 3.5. This assumption is supported by the Fermi sphere–Brillouin zone interaction model that increases under compression. The recently found structure of Ca-VII with a tetragonal cell containing 32 atoms (tI32) is similar to that in the intermetallic compound In5Bi3with 3.75 valence electrons per atom. Structural relations are analyzed in terms of electronic structure resemblance. Correlations of structure and physical properties of Ca are discussed.

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Formation of a very high-density amorphous phase of carbon and its crystallization into a simple cubic structure at high pressure

Computational Materials Science ◽

10.1016/j.commatsci.2021.110822 ◽

2021 ◽

Vol 200 ◽

pp. 110822

Author(s):

Murat Durandurdu

Keyword(s):

High Pressure ◽

Amorphous Phase ◽

High Density ◽

Simple Cubic ◽

Cubic Structure ◽

Very High

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Study of physisorption isotherm of water on technical nickel surface with a wide pressure range

Vacuum ◽

10.1016/j.vacuum.2017.08.032 ◽

2017 ◽

Vol 145 ◽

pp. 123-127 ◽

Cited By ~ 2

Author(s):

Yanwu Li ◽

Yongjun Cheng ◽

Wenjun Sun ◽

Yongjun Wang ◽

Meng Dong ◽

...

Keyword(s):

Pressure Range ◽

Nickel Surface ◽

Wide Pressure Range ◽

Wide Pressure

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Adsorption isotherms and kinetics of carbon dioxide on Chinese dry coal over a wide pressure range

Adsorption ◽

10.1007/s10450-015-9649-9 ◽

2015 ◽

Vol 21 (1-2) ◽

pp. 53-65 ◽

Cited By ~ 10

Author(s):

Yongchen Song ◽

Wanli Xing ◽

Yi Zhang ◽

Weiwei Jian ◽

Zhaoyan Liu ◽

...

Keyword(s):

Carbon Dioxide ◽

Adsorption Isotherms ◽

Pressure Range ◽

Adsorption Isotherms And Kinetics ◽

Wide Pressure Range ◽

Kinetics Of ◽

Wide Pressure

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Topological crystallography of gas hydrates

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s2053273315008864 ◽

2015 ◽

Vol 71 (4) ◽

pp. 444-450 ◽

Cited By ~ 2

Author(s):

Sergey V. Gudkovskikh ◽

Mikhail V. Kirov

Keyword(s):

Hydrogen Bonding ◽

Gas Hydrates ◽

Periodic Boundary ◽

Periodic Boundary Conditions ◽

Hexagonal Structure ◽

New Approach ◽

Quotient Graphs ◽

Disordered Structure ◽

Unit Cells ◽

Cubic Structure

A new approach to the investigation of the proton-disordered structure of clathrate hydrates is presented. This approach is based on topological crystallography. The quotient graphs were built for the unit cells of the cubic structure I and the hexagonal structure H. This is a very convenient way to represent the topology of a hydrogen-bonding network under periodic boundary conditions. The exact proton configuration statistics for the unit cells of structure I and structure H were obtained using the quotient graphs. In addition, the statistical analysis of the proton transfer along hydrogen-bonded chains was carried out.

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Design and Simulation of Pressure Sensor for Ocean Depth Measurements

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.313-314.666 ◽

2013 ◽

Vol 313-314 ◽

pp. 666-670 ◽

Cited By ~ 5

Author(s):

K.J. Suja ◽

Bhanu Pratap Chaudhary ◽

Rama Komaragiri

Keyword(s):

Pressure Sensor ◽

Integrated Circuit ◽

Output Voltage ◽

Pressure Sensors ◽

Micro Electro Mechanical System ◽

Constant Thickness ◽

Piezoresistive Pressure Sensor ◽

Wide Pressure Range ◽

Processing Techniques ◽

Wide Pressure

MEMS (Micro Electro Mechanical System) are usually defined as highly miniaturized devices combining both electrical and mechanical components that are fabricated using integrated circuit batch processing techniques. Pressure sensors are usually manufactured using square or circular diaphragms of constant thickness in the order of few microns. In this work, a comparison between circular diaphragm and square diaphragm indicates that square diaphragm has better perspectives. A new method for designing diaphragm of the Piezoresistive pressure sensor for linearity over a wide pressure range (approximately double) is designed, simulated and compared with existing single diaphragm design with respect to diaphragm deflection and sensor output voltage.

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A Study of Film Boiling of Corresponding-States Fluids over a Wide Pressure Range with Cylindrical Heaters

Advances in Cryogenic Engineering ◽

10.1007/978-1-4757-0244-6_50 ◽

1971 ◽

pp. 402-411 ◽

Cited By ~ 3

Author(s):

V. J. Flanigan ◽

E. L. Park

Keyword(s):

Pressure Range ◽

Corresponding States ◽

Film Boiling ◽

Wide Pressure Range ◽

Wide Pressure

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Verteilung und Valenz der Kationen in Spinellsystemen mit Eisen und Chrom, II. Zur Stöchiometrie des Spinells FeCr2O4 / Distribution and Valence of the Cations in Spinel Systems with Iron and Chromium, II. On the Stoichiometry of the Spinel FeCr2O4

Zeitschrift für Naturforschung B ◽

10.1515/znb-1991-0517 ◽

1991 ◽

Vol 46 (5) ◽

pp. 653-661 ◽

Cited By ~ 1

Author(s):

Andreas Eggert ◽

Erwin Riedel

Keyword(s):

Pressure Range ◽

Total Iron ◽

X Ray ◽

Partial Pressures ◽

Wide Pressure Range ◽

Wide Pressure ◽

Additional Phase

FeCr2O4 has been prepared under CO-CO2-atmosphere with oxygen partial pressures between 10-18 and 10-8 bar. X-Ray and Mößbauer investigations show that under higher pressures FeCr2O4 is not stoichiometric but contains Fe(III), and that corund type Cr2O3 as an additional phase has been formed. In the wide pressure range from 10-17 to 10-14 bar the contents of Fe(III) are lower than 1% of total iron, and the corund phase is negligible.

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