Ritu Dubey

High pressure structural phase transition of EuS

We have performed improved interaction potential model (IIPM) which included coulomb interaction, three body interaction, polarizability effect and overlap repulsive interaction to investigate the high pressure structural phase transition of EuS and its structural stability in B1 phase. The phase transition from NaCl (B1) type to CsCl (B2) type structure was found to occur at around 21.1 GPa and equation of state show volume collapse of 11.35%, which are close to the experimental values of transition pressure 21.5 GPa and volume collapse 12.5%.

Pressure-induced structural transformations in SmS

We have iinvestigated the pressure volume relationship, pressure induced structural phase transformation in Samarium Sulphide compound SmS for the first time by using improved interaction potential model (IIPM) which includes Coulomb interaction, three body interaction, Polarizability effect and Overlap repulsive interactions. The calculated pressure and relative compression reveal that this compound shows a B1-B2 phase transition.

Study of covalency in zinc-blend AlAs under high pressure

The pressure induced phase transition and relative volume change, of partially covalent AlAs compound have been investigated by means of two different models (i) interaction potential model (IPM) (ii) modified interaction potential model (MIPM) which includes covalency and zero point energy effects in the previous (IPM) model. It is found that the inclusion of covalency and zero point energy effects in MIPM has improved the results and show a good agreement with available experimental data.

Pressure induced phase transition of XN (X=B, Ga) compounds

The pressure induced phase transition, volume collapse and elastic properties have been investigated by means of two different models (1) modified interaction potential model (MIPM) which includes the three body interaction, covalency effect, overlap repulsive interaction up to second neighbour ions and van der Waal interaction. (2) Interaction potential model (IPM) which exclude the covalency effect in previous (IPM) model. The BN and GaN transform from B3 to B1 structure under high pressure (pt= 555 GPa and 37GPa) and show the volume collapse of 3.6% and 16.53%. The elastic constants have also been obtained. The results are in good agreement with the experimental and theoretical data where available.

High pressure structural phase transition of osmium nitride (OsN)

The structural phase transition and relative volume change of OsN compound has been investigated by means of interaction potential model (IPM) which consists of Coulomb interaction, three-body interaction (TBI), van der Waal interaction (vdW) and short range overlap repulsive interactions up to second neighbor ions. It is found that the OsN transforms from zinc-blende structure (B3) to rock-salt structure (B1) at 87.0 GPa. The second order elastic constants are also investigated. These results are compared with available results.

Study of elastic behavior of alloy BxGa1-xNby using bowing parameter

We have investigated the second order elastic constants for the alloy BxGal-xN. By using interaction potential model (IPM) which consists of Coulomb interaction, three-body interaction, van der Waal interaction and short range overlap repulsive interactions. The second order elastic constants with composition are obtained with and without (including Vegard’s law) bowing parameter. The bowing parameter shows the deviation from Vegard’s law.

Study of elastic behavior of alloy B[sub x]Ga[sub 1-x]N by using bowing parameter

We have investigated the second order elastic constants for the alloy BxGal-xN. By using interaction potential model (IPM) which consists of Coulomb interaction, three-body interaction, van der Waal interaction and short range overlap repulsive interactions. The second order elastic constants with composition are obtained with and without (including Vegard’s law) bowing parameter. The bowing parameter shows the deviation from Vegard’s law.

Study of elastic behavior of alloy BxGa1-xN by using bowing parameter

We have investigated the second order elastic constants for the alloy BxGal-xN. By using interaction potential model (IPM) which consists of Coulomb interaction, three-body interaction, van der Waal interaction and short range overlap repulsive interactions. The second order elastic constants with composition are obtained with and without (including Vegard’s law) bowing parameter. The bowing parameter shows the deviation from Vegard’s law.

Structural Behaviour of Uranium Sulfide under High Pressure

The study of pressure induced structural phase transition of uranium sulphide, which crystallizes in rock salt (B1) structure, has been performed using the well described three body interaction model (TBIPM). Our present TBIP model consists of long range coulombic interaction, three body interactions, Hafemeister and Flygare type short–range overlap repulsion extended upto the second neighbor ions and the van der Waals interaction. The present results are in good agreement with the available experimental data on the phase transition pressure (Pt = 80.2 GPa). So it can be considered as an adequate and suitable model to perform high pressure studies.