Role of temperature in the numerical analysis of CaO under high pressure

Bhardwaj, Purvee; Singh, Sadhna

doi:10.2478/s11532-009-0117-9

Cited by 9 publications

(4 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For cubic crystals, potential parameters A, ξ, p and q are related [4] to V 0 , cohesive energy (E c ), B 0 and B ´. Here, r 0 is the nearest neighbour distance and ( )…”

Section: Formulationmentioning

confidence: 99%

“…The main focus of the present study is the examination of equation of state (EOS) for FeO, as a representative candidate for the lower mantle, under the simultaneous high-P,T conditions. Unfortunately, however, since complete ab initio calculations are, usually, accurate and computationally less-expensive only at ambient condition, some simple approximate schemes have been employed to examine materials behaviours at such extreme conditions [4][5][6]. In this regard, we have used tight-binding energy model within the second-moment approximation [7] (TB-SMA) to extrapolate ambient condition results, which were obtained using the self-consistent density functional formalism.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Structural and Vibrational Properties of FeO Using First-Principles

Bhatt

Patel

Vahora

et al. 2013

AMR

View full text Add to dashboard Cite

We have studied the equation of states and vibrational properties of FeO using DFT based plane-wave pseudopotential (PW-DFT) within the generalized gradient approximation. The calculated cohesive properties at ambient condition, namely, lattice constant (a0), bulk modulus (B0) and its first pressure derivative (), are reported for B1-phase of FeO, in agreement with previous experimental and other theoretical results. A linear-response approach to the density functional theory was used to derive the phonon frequencies and phonon density of state (p-dos). Further, in order to calculate both static and dynamic equations of states, nearest-neighbour second-moment tight-binding energy model (TB-SMA) was used. Parameters of the present TB-SMA model were determined by the presentab initiopseudopotential calculations. It is found that the present simple TB-SMA scheme is able to mimic shock Hugoniot for such oxides correctly.

show abstract

“…For cubic crystals, potential parameters A, ξ, p and q are related [4] to V 0 , cohesive energy (E c ), B 0 and B ´. Here, r 0 is the nearest neighbour distance and ( )…”

Section: Formulationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Structural and Vibrational Properties of FeO Using First-Principles

Bhatt

Patel

Vahora

et al. 2013

AMR

View full text Add to dashboard Cite

show abstract

“…Upon compression, these metal oxides usually undergo a body centred cubic CsCl-type (B2) structure and it is well established for MgO, CaO and SrO. Amongst all these compounds, BaO has interesting structural properties and it exhibits a rich polymorphism in the pressure range of 0-1.5 Mbar over the remaining alkaline earth oxides, CaO, [16][17][18][19][20][21][22][23][24] SrO. [16][17][18][19][25][26][27][28][29] Therefore, understanding the high pressure structural and lattice dynamical behavior of BaO is crucial as this can be a possible candidate of the Earth's mantle.…”

Section: Introductionmentioning

confidence: 99%

Lattice instability and Raman spectra of BaO under high pressure: A first principles study

Lavanya,

Yedukondalu,

Roshan

et al. 2022

Preprint

View full text Add to dashboard Cite

Alkaline-earth metal oxides, in particular MgO and CaO dominate Earth's lower mantle, therefore, exploring high pressure behavior of this class of compounds is of significant geophysical research interest. Among all these compounds, BaO exhibits rich polymorphism in the pressure range of 0-1.5 Mbar. Static enthalpy calculations revealed that BaO undergoes a pressure induced structural phase transition from NaCltype (B1) → NiAs-type (B8) → distorted CsCl-type (d-B2) → CsCl-type (B2) at 5.1, 19.5, 120 GPa respectively. B1 → B8 & B8 → d-B2 transitions are found to be first order in nature whereas d-B2→ B2 is a second order or weak first order phase transition. Interestingly, d-B2 phase shows stability over a wide pressure range, ∼19.5-113 GPa. Mechanical and dynamical stabilities of ambient and high pressure phases are demonstrated through computed elastic constants and phonon dispersion curves, respectively. Under high pressure, significant phonon softening and soft phonon mode along M-direction are observed for B8, d-B2 and B2 phases, respectively. Pressure dependent Raman spectra suggest a phase transition from d-B2 to Raman inactive phase under pressure. Overall, the present study provides a comprehensive understanding of underlying mechanisms behind pressure-induced structural phase transitions in BaO.

show abstract

“…[17,36] Our calculated values of shear modulus G of MgO at zero pressure and high temperature are listed in Table 5. The obtained value of shear modulus G agrees well with available experimental and theoretical values.…”

mentioning

confidence: 99%

Pressure-induced phase transition and structural behavior of MgO at high temperatures: a model study

2014

Self Cite

View full text Add to dashboard Cite

A realistic interaction potential model approach by including temperature effects is developed to study phase transition, elastic properties and thermo-physical properties at very high pressures and temperatures. This approach is effectively able to explain the inter-atomic interaction involved at high temperature and high pressure as it includes the three-body interactions. Earlier works overlooked the three-body interactions at high temperature and pressures. Moreover, the phase-transition pressures of MgO crystal at high temperatures including the three-body interaction are computed for the first time. Elastic behavior, anisotropic factor and Debye temperature of MgO at high pressures and temperatures are also reported.

show abstract

Role of temperature in the numerical analysis of CaO under high pressure

Cited by 9 publications

References 44 publications

Structural and Vibrational Properties of FeO Using First-Principles

Structural and Vibrational Properties of FeO Using First-Principles

Lattice instability and Raman spectra of BaO under high pressure: A first principles study

Pressure-induced phase transition and structural behavior of MgO at high temperatures: a model study

Contact Info

Product

Resources

About