Influence of concentration on the structural-phase-transition pressure of the II-VI ternary alloyZnxCd1−xS

1991 ◽  
Vol 44 (8) ◽  
pp. 3650-3654 ◽  
Author(s):  
Alain Béliveau ◽  
Cosmo Carlone
Keyword(s):  
Phase Transition ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Transition Pressure ◽  
Phase Transition Pressure

Structural and elastic properties of barium chalcogenides (BaX, X=O, Se, Te) under high pressure

Open Physics ◽  
2008 ◽  
Vol 6 (2) ◽  
Author(s):  
Purvee Bhardwaj ◽  
Sadhna Singh ◽  
Neeraj Gaur
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Elastic Constants ◽  
Structural Phase ◽  
Transition Pressure ◽  
Phase Transition Pressure ◽  
Cscl Structure ◽  
Three Body ◽  
Derivatives Of ◽  
Good Agreement

AbstractIn the present paper we have investigated the high-pressure, structural phase transition of Barium chalcogenides (BaO, BaSe and BaTe) using a three-body interaction potential (MTBIP) approach, modified by incorporating covalency effects. Phase transition pressures are associated with a sudden collapse in volume. The phase transition pressures and associated volume collapses obtained from TBIP show a reasonably good agreement with experimental data. Here, the transition pressure, NaCl-CsCl structure increases with decreasing cation-to-anion radii ratio. In addition, the elastic constants and their combinations with pressure are also reported. It is found that TBP incorporating a covalency effect may predict the phase transition pressure, the elastic constants and the pressure derivatives of other chalcogenides as well.

scholarly journals Structural phase transition and photoluminescence properties of wurtzite CdS:Eu3+ nanoparticles under high pressure

RSC Advances ◽  
2017 ◽  
Vol 7 (50) ◽  
pp. 31433-31440 ◽  
Author(s):  
Rui Zhao ◽  
Tianye Yang ◽  
Yang Luo ◽  
Mingyan Chuai ◽  
Xiaoxin Wu ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Cds Nanoparticles ◽  
Pressure Probe ◽  
Photoluminescence Properties ◽  
Rocksalt Structure ◽  
Phase Transition Pressure ◽  
The Eu

Eu dopant increases the phase transition pressure from wurtzite to rocksalt structure compared with CdS nanoparticles. The PL peaks of the Eu3+ ions can used as pressure probe after the quenching of the PL peaks of rocksalt structure CdS.

High Pressure Structural Phase Transition and Elastic Properties of MgX (X = S, Se, Te) Semiconducting Compounds

2006 ◽  
Vol 987 ◽  
Author(s):  
Dinesh Varshney ◽  
Netram Kaurav ◽  
Kamal Kumar Choudhary ◽  
R. Kinge ◽  
R. K. Singh
Keyword(s):  
Phase Transition ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Repulsive Interaction ◽  
Interionic Interaction ◽  
Phase Transition Pressure ◽  
Cscl Type ◽  
Semiconducting Compounds ◽  
Structural Aspects ◽  
Vdw Interaction

AbstractPressure-induced structural aspects of NaCl-type (B1) to CsCl-type (B2) structure in MgX [X = S, Se, Te] semiconductors are presented. An effective interionic interaction potential (EIOP) with long range Coulomb, van der Waals (vdW) interaction and the short-range repulsive interaction upto second-neighbor ions within the Hafemeister and Flygare approach is developed. Particular attention is devoted to evaluate the vdW coefficients following the variational method, as both the cation and the anion are polarizable. Our result on vast volume discontinuity in pressure volume phase diagram identifies the structural phase transition from B1 to B2 structure. The estimated value of the phase transition pressure (Pt) is consistent with results previously published. The variations of elastic constants with pressure follow a systematic trend identical to that observed in others compounds of NaCl type structure family.

BAND STRUCTURE, METALLIZATION, AND SUPERCONDUCTIVITY OF GaAs AND InAs UNDER HIGH PRESSURE

2007 ◽  
Vol 06 (04) ◽  
pp. 833-843 ◽  
Author(s):  
A. AMALRAJ ◽  
C. NIRMALA LOUIS ◽  
SR. GERARDIN JAYAM
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Band Structure ◽  
Structural Phase Transition ◽  
Electronic Band Structure ◽  
Structural Phase ◽  
Normal Structure ◽  
Superconducting Transition ◽  
Electronic Band ◽  
Phase Transition Pressure

The electronic band structure, metallization, structural phase transition, and superconductivity of cubic zinc blende type GaAs and InAs are investigated. The equilibrium lattice constant, bulk modulus, and the phase transition pressure at which the compounds undergo structural phase transition from ZnS to NaCl are predicted from the total energy calculations. The density of states at the Fermi level (N(E F )) get enhanced after metallization, which leads to the superconductivity in GaAs and InAs . The superconducting transition temperatures (T c ) of GaAs and InAs are obtained as a function of pressure for both the ZnS and NaCl structures. GaAs and InAs come under the class of pressure-induced superconductors. When pressure is increased T c increases in both the normal and high pressure-structures. The dependence of T c on electron–phonon mass enhancement factor λ shows that GaAs and InAs are electron–phonon-mediated superconductors. Also, it is found that GaAs and InAs retained in their normal structure under high pressure give appreciably high T c .

STRUCTURAL PHASE TRANSITION IN BORON COMPOUNDS AT HIGH PRESSURE

2010 ◽  
Vol 24 (10) ◽  
pp. 1235-1244 ◽  
Author(s):  
MINA TALATI ◽  
PRAFULLA K. JHA
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Elastic Constants ◽  
Structural Phase ◽  
Boron Compounds ◽  
Potential Approach ◽  
Transition Pressure ◽  
Zinc Blende ◽  
Phase Transition Pressure ◽  
Good Agreement

The high-pressure induced structural phase transitions and pressure induced elastic and anharmonic behavior of boron compounds viz. BN, BP, and BAs have been investigated using an inter-ionic potential approach based on charge transfer effect. These compounds go to NaCl phase (B1) under pressure from zinc blende phase (B3). The variations of second-order elastic constants and their combinations follow a systematic trend with pressure, identical to that observed in other compounds of zinc blende structure family. Shear stiffness constants decrease with increasing pressure up to phase transition pressure. The bulk moduli of these compounds are in reasonably good agreement with other theoretical and experimental data. The values of phase transition pressure of these compounds obtained by using the present approach are also in good agreement with those predicted by using the pseudo potential approach. The present approach has also succeeded in predicting the Born and relative stability criterion for stable zinc blende phase of these compounds. We also present a set of third-order elastic constants and pressure derivatives of second-order elastic constants for boron compounds.

Pressure Induced Structural Phase Transition in InP at Room Temperature

2016 ◽  
Vol 28 ◽  
pp. 98-100
Author(s):  
Pooja Pawar ◽  
Shilpa Kapoor ◽  
Sadhna Singh
Keyword(s):  
Phase Transition ◽  
Structural Phase ◽  
Theoretical Data ◽  
Effect Of Temperature ◽  
Repulsive Interaction ◽  
Transition Pressure ◽  
Phase Transition Pressure ◽  
Realistic Interaction ◽  
Range Overlap ◽  
Three Body

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.

Study of Structural, Elastic Properties and their Pressure Dependence in IrN Compound

2016 ◽  
Vol 28 ◽  
pp. 16-22 ◽  
Author(s):  
Shubhangi Soni ◽  
Arvind Jain ◽  
Kamal Kumar Choudhary ◽  
Netram Kaurav
Keyword(s):  
Phase Transition ◽  
Theoretical Study ◽  
Structural Phase ◽  
Elastic Behavior ◽  
Interionic Interaction ◽  
First Order ◽  
Transition Pressure ◽  
Zinc Blende ◽  
Phase Transition Pressure ◽  
Cscl Structure

A theoretical study of the elastic behavior in IrN compound using effective interionic interaction potential is carried out. The estimated values of phase transition pressure and the vast volume discontinuity in pressure-volume (PV) phase diagram indicate the structural phase transition from zinc blende (B3) to CsCl structure (B2). C11, C12 and C44 increase nearly linearly with pressure. At phase transition pressure IrN has shown a discontinuity in second order elastic constants, which is in accordance with the first-order character of the phase transition.

High-Pressure Structural Phase Transition in MgxCd1-xO Compounds

2016 ◽  
Vol 28 ◽  
pp. 77-84
Author(s):  
Saligram Verma ◽  
Arvind Jain ◽  
Kamal Kumar Choudhary ◽  
Netram Kaurav
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Physical Properties ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Repulsive Interaction ◽  
Interionic Interaction ◽  
Phase Transition Pressure ◽  
Cscl Structure ◽  
Physical Interactions

The high-pressure technique is useful to understand physical properties because the technique can directly control bond length and phase transition. As a general trend, the pressure-induced phase transition causes an increase of coordination number with a drastic change of their physical properties. Here, we attempt to explore the pressure-induced phase transitions from the sixfold-coordinated NaCl structure (B1) to the eightfold-coordinated CsCl structure (B2) in MgxCd1−xO by applying an effective interionic interaction potential, which includes the long range Coulomb, van der Waals (vdW) interaction and the short-range repulsive interaction upto second-neighbor ions within the Hafemeister and Flygare approach. Assuming that both the ions are polarizable, the Slater-Kirkwood variational method is employed to estimate the vdW coefficients for parent compounds. The estimated values of the phase transition pressure (Pt) increase with Mg concentration. The vast volume discontinuity in pressure volume phase diagram identifies the structural phase transition from B1 to B2 structure. The results obtain from the present calculations requires the complete understanding of many physical interactions that are essential to ternary oxides, containing elements with size and chemical mismatch, will lead to a consistent explanation of the documented structural properties.

High Pressure Structural Phase Transition and Elastic Properties of Europium Chalcogenides

2014 ◽  
Vol 1047 ◽  
pp. 163-169
Author(s):  
Ashvini K. Sahu ◽  
M. Aynyas ◽  
R. Bhardwaj ◽  
Sankar P. Sanyal
Keyword(s):  
Experimental Data ◽  
Phase Transition ◽  
High Pressure ◽  
Elastic Properties ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Phase Transition Pressure ◽  
Ionic Nature ◽  
Three Body ◽  
Body Potential

The high pressure induced structural phase transition and elastic properties of three Europium chalcogenides (EuX; X = S, Se, Te) have been studied using a two body potential approach. The calculated compression curves of EuS, EuSe and EuTe obtained so has been compared with recently measured three body potential data. The calculated transition pressures are in good agreement with the experimental data. The phase transition pressure for EuS, EuSe and EuTe going from the NaCl phase to CsCl phase have been observed are 22 GPa, 15 GPa, 10 GPa respectively, close the theoretical and experimental data. We have also calculated bulk modulas and second order elastic constants at high pressure which show partly ionic nature of theses compounds. The B1 (NaCl) phase is found to be higher in energy than the B2 (CsCl) phase and more stable at zero pressure.

scholarly journals BAND STRUCTURE, METALLIZATION AND STRUCTURAL PHASE TRANSITION OF NABR UNDER HIGHPRESSURE

2020 ◽  
Vol 5 (2) ◽  
pp. 108-116
Author(s):  
P.Penila Saminy ◽  
Y. Ramola ◽  
C.Nirmala Louis
Keyword(s):  
Phase Transition ◽  
Band Structure ◽  
Bulk Modulus ◽  
Band Gap ◽  
Structural Phase Transition ◽  
Structural Phase ◽  
Normal Pressure ◽  
Pressure Derivative ◽  
Phase Transition Pressure ◽  
Direct Band

The metallization and the phase transition of the alkali bromide sodium bromide (NaBr) is investigated through its band structure. The equilibrium lattice constant, bulk modulus, pressure derivative of bulk modulus and the phase transition pressure at which the compound undergo structural phase transition from NaCl (B1) to the CsCl (B2) structure is predicted from the total energy calculations. The ground state properties and band gap values are compared with the experimental and other theoretical results. At normal pressure NaBr is a direct band gap insulator. When the pressure is increased there is enhanced overlapping between the wave functions of the neighboring atoms. As a result the widths of the valence and empty conduction bands increase. These changes lead to the narrowing and indirect closing of band gap in NaBr (metallization). It is also confirmed that the metallization and structural phase transition do not occur simultaneously in ionic compounds.

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