The effect of solid solutions upon the bulk modulus and its pressure derivative: implications for equations of state

1969 ◽  
Vol 7 (2) ◽  
pp. 137-140 ◽  
Author(s):  
Edward Schreiber
Keyword(s):  
Bulk Modulus ◽  
Solid Solutions ◽  
Equations Of State ◽  
Pressure Derivative

High pressure studies on the packing forces and intermolecular interaction in polyphenyls

2003 ◽  
Vol 771 ◽  
Author(s):  
G. Heimel ◽  
P. Puschnig ◽  
M. Oehzelt ◽  
K. Hummer ◽  
B. Koppelhuber-Bitschnau ◽  
...  
Keyword(s):  
Bulk Modulus ◽  
Structural Changes ◽  
Equations Of State ◽  
Ambient Conditions ◽  
X Ray Diffraction ◽  
Pressure Derivative ◽  
Molecular Arrangement ◽  
High Pressure Studies ◽  
Phenyl Rings ◽  
Induced Changes

AbstractIn this work, we report on pressure induced structural changes in crystalline oligo(paraphenylenes) containing two to six phenyl rings. Revisiting the crystal structures at ambient conditions reveals details in the packing principle. A linear relationship between the density at ambient conditions and the number of phenyl rings is found. Energy dispersive X-ray diffraction has been performed in a systematic study on polycrystalline powders of biphenyl, paraterphenyl, p-quaterphenyl, p-quinquephenyl and p-sexiphenyl under hydrostatic pressure up to 60 kbar. Our investigations not only yield pressure dependent lattice parameters and hints towards pressure induced changes in the molecular arrangement, but also allow for an analysis of the equations of state of these substances as a function of oligomer length. We report the previously unknown bulk modulus of p-quaterphenyl, p-quinquephenyl, and p-sexiphenyl (B0 = 83 kbar, 93 kbar, and 100 kbar respectively) and its pressure derivative (B0' = 6.4, 7.5, and 5.6). A linear dependence of the bulk modulus on the inverse number of phenyl rings in the molecules is found.

The effect of Al/Si disorder on the bulk moduli of plagioclase feldspars

2010 ◽  
Vol 74 (6) ◽  
pp. 943-950 ◽  
Author(s):  
L. M. Sochalski-Kolbus ◽  
R. J. Angel ◽  
F. Nestola
Keyword(s):  
Bulk Modulus ◽  
Single Crystal ◽  
Equations Of State ◽  
X Ray Diffraction ◽  
Volume Increase ◽  
X Ray ◽  
Density Decrease ◽  
The Relationship

AbstractThe volumes of a disordered An20 (Qod = 0.15), a disordered An78 (Qod = 0.55) and an ordered An78 (Qod = 0.81) were determined up to 9.569(10) GPa, 8.693(5) GPa and 9.765(10) GPa, respectively, using single-crystal X-ray diffraction. The volume variations with pressure for these samples are described with 4th-order Birch Murnaghan equations of state with V0 = 669.88(7) Å3, K0 = 59.7(7) GPa. K′ = 5.7(5), K″ = −0.8(2) GPa−1 for disordered An20, V0 = 1340.48(10) Å3, K0 = 77.6(5) GPa, K0′ = 4.0(3), K″ = -0.59(9) GPa−1 for disordered An78 and V0 = 1339.62(6) A3, K0 = 77.4(6) GPa, K′ = 4.2(4), and K″ = −0.7(1) GPa−1 for ordered An78. Along with data from previous studies (An0 ordered, An0 disordered and An2o ordered), the volumes for the disordered samples were found to be up to ∼0.3% larger than the ordered samples of the same composition. The disordered samples are softer than the ordered samples of the same composition by 4(1)% for An0, 2.5(9)% for An20 and essentially zero for An78. The relationship between volume increase, density decrease, and decreasing bulk modulus with increasing disorder is in accordance with Birch's Law.

scholarly journals Elastic Behaviour of Diborides Under High Pressure

2009 ◽  
Vol 1 (2) ◽  
pp. 275-280
Author(s):  
Seema Gupta ◽  
S. C. Goyal
Keyword(s):  
High Pressure ◽  
Equation Of State ◽  
Statistical Model ◽  
Bulk Modulus ◽  
Electron Gas ◽  
Elastic Behaviour ◽  
Pressure Derivative ◽  
First Order ◽  
Elastic Data ◽  
Quantum Statistical

The present study deals with the elastic behaviour of diborides (BeB2, MgB2 and NbB2) under high pressure with the help of equation of state (EOS) using the elastic data reported by Islam et al. It is concluded that EOS, which are based either on quantum statistical model or  pseduopotential model, only are capable of explaining high pressure behaviour of the solids under study.  Moreover the value of first order pressure derivative of bulk modulus at infinite pressure (Kinfinity) is greater than 5/3 and thus the diborides under study do not behave as Thomas-Fermi electron gas under high compression. Keywords: Equation of state; High Pressure; Diborides. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v1i2.1189 

First-principles prediction of a new high pressure polymorph of the BaSi2 compound

2014 ◽  
Vol 28 (11) ◽  
pp. 1450089 ◽  
Author(s):  
Raouf Beddiaf ◽  
Yassine Djaballah ◽  
Hichem Bouderba ◽  
Aissa Belgacem-Bouzida
Keyword(s):  
High Pressure ◽  
First Principles ◽  
Equations Of State ◽  
Structural Parameters ◽  
Hexagonal Structure ◽  
Enthalpies Of Formation ◽  
Generalized Gradient ◽  
Symbol Space ◽  
Pressure Derivative ◽  
Pearson Symbol

In this paper, we present a study of the structural stability of BaSi 2 under high pressure based on first-principles calculations using the projector augmented wave method and generalized gradient approximation as implemented in the ABINIT code. The equations of state of three known polymorphs of BaSi 2 and four candidate structures are calculated along with their structural parameters and their enthalpies of formation. A new polymorph of BaSi 2, not yet reported experimentally, is found to be more stable than all the other structures at high pressure and 0 K. It corresponds to the MgZn 2-type (h) hexagonal structure with hP12 Pearson symbol (space group: P63/mmc. The stiffness coefficients Bij and elastic properties including bulk modulus B0 with its first and second pressure derivative (B′, B′′), Young's modulus (E) and Poisson's ratio (ν) are computed using the stress–strain method.

Theoretical Investigations of Some Physical Properties of HgX (X = S, Se and Te) Semiconducting Compounds

2016 ◽  
Vol 1141 ◽  
pp. 153-155 ◽  
Author(s):  
A.R. Jivani ◽  
J.K. Baria ◽  
Paresh S. Vyas ◽  
Ashvin R. Jani
Keyword(s):  
Physical Properties ◽  
Bulk Modulus ◽  
Elastic Constants ◽  
Correlation Effect ◽  
Model Potential ◽  
Correction Function ◽  
Perturbation Scheme ◽  
Pressure Derivative ◽  
Semiconducting Compounds ◽  
Theoretical Results

In the present work, we have investigated total energy, bulk modulus, elastic constants, pressure derivatives of elastic constants and pressure derivative of bulk modulus of HgX (X=S, Se and Te) semiconducting compounds using higher-order perturbation scheme with the application of our own proposed model potential. To consider exchange and correlation effect to the dielectric function, the local-field correction function proposed by Farid et al is employed in the present study. In most of the cases the experimental and other theoretical results of the aforesaid physical properties of the HgX are not available in the literature and hence this study provides a better set of theoretical results of the physical properties of the materials for future comparison either with theoretical or experimental results.

The Study of High Pressure and Bulk Modulus of Metals by Equations of State

2016 ◽  
Vol 5 (3) ◽  
pp. 397-400
Author(s):  
R. S. Singh ◽  
Deepti Sahrawat
Keyword(s):  
High Pressure ◽  
Bulk Modulus ◽  
Equations Of State

Structural, Electronic and Elastic Properties of CeTl Intermetallic Compound

2016 ◽  
Vol 28 ◽  
pp. 1-4
Author(s):  
Deepika Shrivastava ◽  
Sankar P. Sanyal
Keyword(s):  
Bulk Modulus ◽  
Elastic Properties ◽  
Density Functional ◽  
Full Potential ◽  
Generalized Gradient ◽  
Pressure Derivative ◽  
Functional Theory ◽  
Augmented Plane Wave ◽  
Cscl Type ◽  
Linearized Augmented Plane Wave

The structural, electronic and elastic properties of CeTl with CsCl-type B2 structure have been investigated using full-potential linearized augmented plane wave (FP-LAPW) method based on density functional theory (DFT) within the generalized gradient approximation (GGA) for exchange and correlation potential. The ground state properties such as lattice constant, bulk modulus and pressure derivative of bulk modulus have been calculated which are in good agreement with available experimental data. The band structure and density of state depict that 4f electrons of Ce element have dominant character in electronic conduction and are responsible for metallic character of CeTl. The charge density plot reveals that the metallic as well as ionic bonding exist between Ce and Tl atoms. The calculated elastic constants indicate that CeTl is mechanically stable in cubic B2 phase and found to be ductile in nature.

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