Shilpa Kapoor

Study of phase transformation and elastic properties of ThX (X = N, P, As and Sb) under high-pressure

ABSTRACT An improved interaction potential model (IIPM) has been formulated to theoretically predict the pressure induced phase transition, elastic properties and thermophysical properties of thorium monopnictides (ThX; X = N, P, As and Sb). The phase transition pressures and volume drop obtained from this model show a better agreement with the available experimental than theoretical results. We have achieved elastic moduli, anisotropy factor, Poissons ratio, Kleinman parameter, shear and stiffness constants on the basis of the calculated elastic constants. To know the anharmonic properties, we have also computed the third-order elastic constants, first-order pressure derivatives of second-order elastic constants and thermophysical quantities. Our results are in reasonable agreement with available measured and others reported data which supports the validity of model.

Structural and elastic properties of KBr at high pressure and high temperature

ABSTRACT To study phase transition and elastic properties at high pressures and high temperatures, we have developed a realistic interaction potential model (RIPZpe) including temperature effects. This model is completely suitable for explaining the inter-atomic interaction involved at high temperature and high pressure as it includes the three-body interaction (TBI) and zero point energy effects. The phase transition of KBr crystal at high pressure and high temperatures including the TBI is done for the first time. We have estimated the phase transition pressures, volume collapses and elastic behaviour at various high pressure and high temperatures by RIPZpe approach and the results found are well suited with available experimental data.

Investigation of structural and mechanical properties of rare-earth bismuthide (RBi, R=Ce & Pr) with the NaCl structure at high pressure

We have investigated the structural and mechanical properties of Cerium and Praseodymium Bismuthides under pressure by means of a three body interaction potential model which includes long range columbic interaction, three body interactions and short range overlap repulsive interaction operative up to second nearest neighbor. These compounds shows transition from NaCl structure to body-centered tetragonal (BCT) structure (distorted CsCl-type P4/mmm). The elastic constants and their properties are also reported. Our calculated results of phase transitions and volume collapses of these compounds show a good agreement with available theoretical and experimental results.We have investigated the structural and mechanical properties of Cerium and Praseodymium Bismuthides under pressure by means of a three body interaction potential model which includes long range columbic interaction, three body interactions and short range overlap repulsive interaction operative up to second nearest neighbor. These compounds shows transition from NaCl structure to body-centered tetragonal (BCT) structure (distorted CsCl-type P4/mmm). The elastic constants and their properties are also reported. Our calculated results of phase transitions and volume collapses of these compounds show a good agreement with available theoretical and experimental results.

Structural phase stability, mechanical and anharmonic properties of actinide sulfides: a high pressure study with the role of temperature

Abstract Vital properties (structural and thermo-elastic) of materials are affected on the application of pressure and temperature. These properties play a key role in understanding the thermodynamic behavior and equation of state. Thus, we have formulated a realistic interaction potential model to study the structural and thermo-elastic of US and ThS including the temperature effects. This model is used for the present compounds in a high-pressure study including temperature effects. We have computed phase transition pressures, volume drop, elastic and thermal properties at different pressures, and elevated temperatures. Our results are in agreement with available experimental and theoretical data.

Analysis of structural and elastic properties of SmS under high pressure including temperature effects

ABSTRACT The pressure induced phase transition in samarium sulphide is studied by realistic interaction potential model (RIPM) including temperature effects and is consists of coulomb interaction, three body interaction and short range overlap repulsive interaction up to first neighbour. It is found that SmS undergo a structural phase transition from NaCl (B1) type to CsCl (B2) type at 41.92 GPa at 0 K and 38.5 GPa at 300 K respectively. We have also found the second order elastic constants and brittleness of present compound. Our results are in good agreement with the experimental data.

Theoretical prediction of high pressure structural phase transition in PuBi with NaCl structure

ABSTRACT In the present paper, we have investigated the high-pressure structural phase transition of plutonium bismuthide. We studied theoretically the structural properties of this compound (PuBi) by using the three-body potential model (TBI). This compound exhibits first order crystallographic phase transition from NaCl (B1) to body centred tetragonal (BCT) phase at 9.5GPa. The phase transition pressures, associated volume collapse and elastic behaviour of PuBi obtained from three body interaction (TBI) model show a good agreement with available experimental data.

Pressure Induced Structural Phase Transition in InP at Room Temperature

We have investigated the pressure induced phase transition of InP from ZB to NaCl structure associated by using realistic interaction potential model (RIPM), which is modified by taking effect of temperature. This model consists of coulomb interaction, three body interaction, and short range overlap repulsive interaction up to second nearest neighbour. Phase transition pressure is associated with a sudden collapse in volume showing the incidence of first order phase transition. The phase transition pressure and associated volume collapses obtained from present model show a generally good agreement with the available experimental and theoretical data.

Inclusion of electronic polarizability effect in high pressure structural properties of alloy of rare-earth antimonides

In the present paper, we have investigated the high-pressure structural phase transition of rare-earth antimonides (NdSb and DySb). We studied theoretically the structural properties of alloy of these compounds (NdSb and DySb) by using the three-body potential model with the effect of electronic polarizability (TBIPEP). These compounds exhibit first order crystallographic phase transition from NaCl (B1) to CsCl (B2) phase at 17.8 GPa and 22.6 GPa respectively. The study has been extended to mixed crystals and the effect of composition on transition pressure and volume change is investigated. The phase transition pressures and associated volume collapse obtained from present potential model (TBIPEP) show a good agreement with available experimental data.