Zinc-blende to rock-salt structural phase transition of BP and BAs under high pressure

This paper discusses the high pressure-dependent crystal structure phase transformation and elastic behavior of ZnSe[Formula: see text]Te[Formula: see text] (x = 0.0, 0.2, 0.55, 0.81, 0.93 and 1.0) by speculating effective interionic interaction potential (EIoIP), that contains long-range type Coulomb force, short-range overlap repulsion of the Hafemeister and Flygare types and the van der Waals (vdW) interaction. The assessed values of structural phase transition pressure and the considerable volume discontinuity associated with the pressure–volume phase diagram support the structural phase transformation from zinc blende (B3) type to rock-salt (B1) type crystal structure. The equation of state curves (relationship between V(p)/V(0) and pressure in the pressure–volume phase diagram) for both the zinc blende (B3) and rock-salt (B1) structures is in reasonably good agreement with that of experimental observations. Moreover, systematic variations of the second-order elastic constants (SOEC) with pressure have been found to follow systematic trends showed by the other systems with B3 type to B1 type pressure-dependent structural phase transition.

Download Full-text

PRESSURE-INDUCED METALLIZATION AND SUPERCONDUCTIVITY IN InP AND InN

International Journal of Modern Physics B ◽

10.1142/s0217979211058080 ◽

2011 ◽

Vol 25 (04) ◽

pp. 573-587

Author(s):

K. IYAKUTTI ◽

V. REJILA ◽

M. RAJARAJESWARI ◽

C. NIRMALA LOUIS ◽

S. MAHALAKSHMI

Keyword(s):

Phase Transition ◽

High Pressure ◽

Structural Phase Transition ◽

Electronic Band Structure ◽

Indium Nitride ◽

Structural Phase ◽

Superconducting Transition ◽

Electronic Band ◽

Zinc Blende ◽

Lmto Method

The electronic band structure, structural phase transition, metallization and superconducting transition of cubic zinc blende-type indium phosphide ( InP ) and indium nitride ( InN ), under pressure, are studied using TB-LMTO method. These indium compounds become metals and superconductors under high pressure but before that they undergo structural phase transition from ZnS to NaCl structure. The ground-state properties and band gap values are compared with the experimental and previous theoretical results. From our analysis, it is found that the metallization pressure increases with increase of lattice constant. The superconducting transition temperatures (Tc) of InP and InN are obtained as a function of pressure for both the ZnS and NaCl structures and these compounds are identified as pressure-induced superconductors. When pressure is increased Tc increases in both the normal ( ZnS ) and high pressure ( NaCl ) structures. The dependence of Tc on electron–phonon mass enhancement factor λ shows that InP and InN are electron–phonon mediated superconductors. The non-occurrence of metallization, phase transition and onset of superconductivity simultaneously in InP and InN are confirmed.

Download Full-text

HIGH-PRESSURE INDUCED STRUCTURAL PHASE TRANSITION AND ELASTIC PROPERTIES OF DILUTED MAGNETIC SEMICONDUCTORS Zn1-xMnxSe

International Journal of Modern Physics B ◽

10.1142/s021797920803971x ◽

2008 ◽

Vol 22 (17) ◽

pp. 2749-2767 ◽

Cited By ~ 9

Author(s):

DINESH VARSHNEY ◽

V. RATHORE ◽

N. KAURAV ◽

R. K. SINGH

Keyword(s):

Phase Transition ◽

Structural Phase Transition ◽

Rock Salt ◽

Elastic Constants ◽

Diluted Magnetic Semiconductors ◽

Magnetic Semiconductors ◽

Structural Phase ◽

Zinc Blende ◽

Diluted Magnetic ◽

Vdw Interaction

An effective interionic interaction potential is developed to study the pressure-induced phase transitions from zinc blende (B3) to rock salt (B1) structure in diluted magnetic semiconductors Zn 1-x Mn x Se (x=0.08 and 0.15). As a first step, the elastic constants, including the long-range Coulomb, van der Waals (vdW) interaction and the short-range repulsive interaction up to second-neighbor ions within the Hafemeister and Flygare approach, are derived. Assuming that both the ions are polarizable, the Slater–Kirkwood variational method is employed to estimate the vdW coefficients. The estimated values of the phase transition pressure (Pt) increase with Mn concentration. The vast volume discontinuity in the pressure volume phase diagram identifies the structural phase transition from zinc blende to rock salt structure. The variation of second-order elastic constants with pressure resembles that observed in some binary semiconductors. It is noticed that the vdW interaction is effective in obtaining the thermodynamical parameters such as Debye temperature, Gruneisen parameter, and thermal expansion coefficient. However, the inconsistency in the value of pressure derivative of the theoretical and experimental value of C44 is attributed to the fact that we have derived the expressions by assuming that the overlap repulsion is significant only up to nearest neighbors, as well as neglecting thermal effects.

Download Full-text

High-pressure structural phase transition and metallization in Ga2S3 under non-hydrostatic and hydrostatic conditions up to 36.4 GPa

Journal of Materials Chemistry C ◽

10.1039/d0tc06004f ◽

2021 ◽

Author(s):

Linfei Yang ◽

Jianjun Jiang ◽

Lidong Dai ◽

Haiying Hu ◽

Meiling Hong ◽

...

Keyword(s):

Phase Transition ◽

Raman Spectroscopy ◽

High Pressure ◽

Structural Properties ◽

Structural Phase Transition ◽

First Principles ◽

Theoretical Calculations ◽

Structural Phase

The vibrational, electrical and structural properties of Ga2S3 were explored by Raman spectroscopy, EC measurements, HRTEM and First-principles theoretical calculations under different pressure environments up to 36.4 GPa.

Download Full-text