scholarly journals Structural and Thermophysical Properties of Cadmium Oxide

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Purvee Bhardwaj
Keyword(s):  
Phase Transition ◽  
Debye Temperature ◽  
Thermophysical Properties ◽  
Cadmium Oxide ◽  
Molecular Force ◽  
Three Body ◽  
Body Potential ◽  
Model Phase ◽  
Sudden Collapse ◽  
Good Agreement

We have studied the structural and thermophysical properties of cadmium oxide (CdO), using the Three-Body Potential (TBP) model. Phase transition pressures are associated with a sudden collapse in volume. The phase transition pressures and related volume collapses obtained from this model show a generally good agreement with available experimental others data. The thermophysical properties like molecular force constant, Debye temperature, and so forth, of CdO are also reported.

scholarly journals Investigation of Structural Phase Transition of PbS

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Purvee Bhardwaj
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Elastic Properties ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Three Body ◽  
Body Potential ◽  
Model Phase ◽  
Sudden Collapse ◽  
Good Agreement

The high-pressure structural phase transition of semiconductor PbS has been investigated, using the three body potential (TBP) model. Phase transition pressures are associated with a sudden collapse in volume. The phase transition pressures and related volume collapses obtained from this model show a generally good agreement with available results. Moreover, the elastic properties of PbS are also investigated.

Structural and elastic properties of barium chalcogenides (BaX, X=O, Se, Te) under high pressure

Open Physics ◽  
2008 ◽  
Vol 6 (2) ◽  
Author(s):  
Purvee Bhardwaj ◽  
Sadhna Singh ◽  
Neeraj Gaur
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Elastic Constants ◽  
Structural Phase ◽  
Transition Pressure ◽  
Phase Transition Pressure ◽  
Cscl Structure ◽  
Three Body ◽  
Derivatives Of ◽  
Good Agreement

AbstractIn the present paper we have investigated the high-pressure, structural phase transition of Barium chalcogenides (BaO, BaSe and BaTe) using a three-body interaction potential (MTBIP) approach, modified by incorporating covalency effects. Phase transition pressures are associated with a sudden collapse in volume. The phase transition pressures and associated volume collapses obtained from TBIP show a reasonably good agreement with experimental data. Here, the transition pressure, NaCl-CsCl structure increases with decreasing cation-to-anion radii ratio. In addition, the elastic constants and their combinations with pressure are also reported. It is found that TBP incorporating a covalency effect may predict the phase transition pressure, the elastic constants and the pressure derivatives of other chalcogenides as well.

LOW TEMPERATURE SPECIFIC HEAT OF (KBr)1-x(KCN)x MIXED CRYSTAL

2003 ◽  
Vol 17 (26) ◽  
pp. 1391-1398 ◽  
Author(s):  
N. K. GAUR ◽  
NUPINDER KAUR ◽  
MANIK MANAKE ◽  
JYOTSNA GALGALE ◽  
R. K. SINGH
Keyword(s):  
Experimental Data ◽  
Thermal Properties ◽  
Specific Heat ◽  
Mixed Crystal ◽  
Body Force ◽  
Molecular Force ◽  
Low Temperature Specific Heat ◽  
Three Body ◽  
First Time ◽  
Good Agreement

We have investigated the cohesive and thermodynamic properties of ( KBr )1-x( KCN )x using an extended three-body force shell model (ETSM), which has been found to be adequately suitable for the description of orientationally disordered mixed cyanide-halide crystals. The specific heat of ( KBr )1-x( KCN )x for compositions (x=0.53, 0.65, 0.73, 0.84 and 0.93) at temperature 10 K ≤T≤150 K have been computed using the ETSM for the first time. The paper also reports the calculated results on Debye temperature (Θ D ), cohesive energy (Φ), compressibility (β), molecular force constant (f) and Restrahlen frequency (ν0) of ( KBr )1-x( KCN )x. The results on specific heat and some other thermal properties are in good agreement with their available experimental data.

A lattice dynamical study of Cu and Ni based on a new empirical many-body potential

1995 ◽  
Vol 73 (3-4) ◽  
pp. 143-146 ◽  
Author(s):  
I. Akgün
Keyword(s):  
Potential Energy Function ◽  
Many Body ◽  
Dynamical Study ◽  
Dynamical Behaviors ◽  
Atomic Interactions ◽  
The Face ◽  
Experimental Values ◽  
Three Body ◽  
Body Potential ◽  
Good Agreement

In the present work, a recently developed empirical many-body potential-energy function (PEF) is first used, as an application, to investigate the dynamical behaviors of the face-centred-cube d-band metals, Cu and Ni. The new PEF contains both two- and three-body atomic interactions. The two-body potential is a kind of hybrid function and the three-body potential is expressed in terms of the two-body interactions. The parameters defining the PEF for the metals are computed following a procedure similar to a method given by Girifalco and Weizer. The input data for evaluating the necessary parameters are independent of the phonon frequencies and elastic constants of the metals. The phonon frequencies along the principal symmetry directions of Cu and Ni are calculated using the computed two- and three-body force constants. The results are found to be in good agreement with the corresponding experimental values.

Application of a New Three-Body Potential to Vitreous Silica and Sodium Silicate Glasses

1988 ◽  
Vol 141 ◽  
Author(s):  
B. P. Feuston ◽  
R. N. Newell ◽  
S. H. Garofalini
Keyword(s):  
Sodium Silicate ◽  
Silicate Glass ◽  
Md Simulations ◽  
Pair Interaction ◽  
Vitreous Silica ◽  
Static Structure Factor ◽  
Static Structure ◽  
Three Body ◽  
Body Potential ◽  
Good Agreement

AbstractAn empirical three-body potential, suitable for molecular dynamics (MD) simulations, has been developed to model the natural covalency of the Si-O bond in vitreous silica and silicate glass systems. Through the addition of a small directional-dependent three-body term to a previously used modified ionic pair interaction, a narrow distribution of tetrahedral angles and a low concentration of defects were obtained, in good agreement with experiment. The structure of bulk silica resulting from the MD technique also contained a larger average ring size, no edge-sharing tetrahedra, and a calculated static structure factor in good agreement with neutron diffraction results. The simulated sodium silicate glass was also largely improved over previous simulations using pair interactions alone. All silicon atoms were found to be exactly four coordinated while the number of non-bridging oxygen nearly equaled the number of sodium ions present with a reasonable distribution of Qi species.

High Pressure Structural Phase Transition and Elastic Properties of Europium Chalcogenides

2014 ◽  
Vol 1047 ◽  
pp. 163-169
Author(s):  
Ashvini K. Sahu ◽  
M. Aynyas ◽  
R. Bhardwaj ◽  
Sankar P. Sanyal
Keyword(s):  
Experimental Data ◽  
Phase Transition ◽  
High Pressure ◽  
Elastic Properties ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Phase Transition Pressure ◽  
Ionic Nature ◽  
Three Body ◽  
Body Potential

The high pressure induced structural phase transition and elastic properties of three Europium chalcogenides (EuX; X = S, Se, Te) have been studied using a two body potential approach. The calculated compression curves of EuS, EuSe and EuTe obtained so has been compared with recently measured three body potential data. The calculated transition pressures are in good agreement with the experimental data. The phase transition pressure for EuS, EuSe and EuTe going from the NaCl phase to CsCl phase have been observed are 22 GPa, 15 GPa, 10 GPa respectively, close the theoretical and experimental data. We have also calculated bulk modulas and second order elastic constants at high pressure which show partly ionic nature of theses compounds. The B1 (NaCl) phase is found to be higher in energy than the B2 (CsCl) phase and more stable at zero pressure.

Theoretical Analysis of Semiconducting Sm1-xEuxS under Pressure

2017 ◽  
Vol SED2017 (01) ◽  
pp. 8-10
Author(s):  
Ritu Dubey ◽  
Nikita Persai
Keyword(s):  
Experimental Data ◽  
Phase Transition ◽  
Potential Model ◽  
Repulsive Interaction ◽  
Phase Transition Pressure ◽  
Volume Collapse ◽  
Polarizability Effect ◽  
Vegard’S Law ◽  
Three Body ◽  
Good Agreement

We have investigated the phase transition pressure and associated volume collapse in Sm1–XEuXS alloy (0≤x≤1) which shows transition from discontinuous to continuous as x is reduced. The calculated results from present approach are in good agreement with experimental data available for the end point members (x=0 and x=1). The results for the alloy counter parts are also in fair agreement with experimental data generated from the vegard’s law. An improved interaction potential model has been developed which includes coulomb, three body interaction, polarizability effect and overlap repulsive interaction operative up to second neighbor ions. It is found that the inclusion of polarizability effect has improved our results.

Pressure-induced phase transition and thermophysical properties of cubic refractory metal nitrides: theory

2013 ◽  
Vol 91 (1) ◽  
pp. 27-33 ◽  
Author(s):  
Anurag Srivastava ◽  
Bhoopendra Dhar Diwan
Keyword(s):  
Phase Transition ◽  
Thermophysical Properties ◽  
Refractory Metal ◽  
Body Force ◽  
Structural Phase ◽  
Metal Nitrides ◽  
Type Phase ◽  
Three Body ◽  
First Time ◽  
Force Potential

The present paper reports the structural stability, pressure-induced phase transition, and thermophysical properties for refractory metal nitrides (viz: TiN, ZrN, HfN, VN, NbN, and TaN) computed using a three-body force potential model. The structural phase transitions from a parental NaCl (B1) type phase to the most stable CsCl (B2) type phase has been observed in the pressure range 162–370 GPa. Study includes the computation of thermophysical properties (U, f, θD, υ0,γ, β, αV/CV), where some of the properties are being reported for the first time on these materials.

ELASTIC AND THERMAL PROPERTIES OF Sr1-xCaxRuO3

2013 ◽  
Vol 27 (17) ◽  
pp. 1350054 ◽  
Author(s):  
RASNA THAKUR ◽  
RAJESH K. THAKUR ◽  
N. K. GAUR
Keyword(s):  
Experimental Data ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Specific Heat ◽  
Debye Temperature ◽  
Cohesive Energy ◽  
Molecular Force ◽  
Almost All ◽  
Good Agreement ◽  
Rigid Ion Model

We have investigated the elastic and thermal properties of Sr 1-x Ca x RuO 3(0≤x ≤1) perovskite using a modified rigid ion model (MRIM). The trend of variation of our computed specific heat in the temperature range 1 K ≤ T ≤ 1000 K are in good agreement with corresponding experimental data for almost all the compositions (x). The specific heat found to increase with temperature from 1 K to 300 K, while they decrease with concentration (x) for these perovskite ruthenates. Besides, we have reported the thermal properties, like thermal expansion (α), molecular force constant (f), Reststrahlen frequency (υ), cohesive energy (ϕ), Debye temperature (θD) and Gruneisen parameter (γ).

Sign in / Sign up

Export Citation Format

Share Document