Namrata Yaduvanshi

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.

An analysis of pressure-induced phase transition and elastic properties of neodymium monopnictides

We have predicted the phase transition pressures and corresponding relative volume changes of two neodymium monopnictides (NdAs and NdSb) having NaCl-type structure at ambient conditions, using an improved interaction potential model (IIPM) approach. Both the compounds have been found to undergo from their initial NaCl(B1) phase to a body centered tetragonal (BCT) phase at high pressure. Our calculated results of phase transitions, volume collapses and elastic behavior of these compounds are found to be close to the experimental results. This shows that the inclusion of the three-body interaction and polarizability effect makes the present model suitable for high pressure studies.

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.

Exploration of pressure induced phase transition in praseodymium phosphide (PrP) with the NaCl-type structure

The structural stability and elastic properties of PrP has been analyzed under high pressure employing the improved interaction potential model (IIPM). This model consists of long range columbic interaction, three body interaction and the short range overlap repulsive forces operative up to next nearest neighbor ions with the effect of electronic polarizability. This compound undergoes phase transition from rock salt type (B1) to tetragonal (distorted CsCl-type, P4/mmm) structure. The pressure behavior of elastic constants, bulk modulus and shear modulus have been presented and discussed. Moreover, the thermo physical properties such as molecular force constant (f), infrared absorption frequency (v0), Debye temperature (θD) and Grunneisen parameter (γ) have also been predicted. The calculated values of phase transition pressure and associated volume collapse are found to be well suited with experimental values.

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.

Theoretical Analysis of High Pressure Phase Transition of Samarium Bismuthide (SmBi) with a NaCl-Type Structure

In the present paper we have calculated the phase transition and volume collapse of Samarium Bismuthide under pressure using 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 neighbour. This compound undergoes transition from NaCl structure to body-centred tetragonal (BCT) structure (distorted CsCl-type P4/mmm). Our calculated results of phase transitions and volume collapses of SmBi are found to be close to the experimental results.

Pressure induced phase transition and elastic properties of cerium mono-nitride (CeN)

In the present paper, we have investigated the high-pressure structural phase transition and elastic properties of cerium mono-nitride. We studied theoretically the structural properties of this compound (CeN) by using the improved interaction potential model (IIPM) approach. This compound exhibits first order crystallographic phase transition from NaCl (B1) to tetragonal (BCT) phase at 37 GPa. The phase transition pressures and associated volume collapse obtained from present potential model (IIPM) show a good agreement with available theoretical data.In the present paper, we have investigated the high-pressure structural phase transition and elastic properties of cerium mono-nitride. We studied theoretically the structural properties of this compound (CeN) by using the improved interaction potential model (IIPM) approach. This compound exhibits first order crystallographic phase transition from NaCl (B1) to tetragonal (BCT) phase at 37 GPa. The phase transition pressures and associated volume collapse obtained from present potential model (IIPM) show a good agreement with available 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.