Theoretical prediction of the structural, elastic, mechanical and phonon properties of bismuth telluride under pressure

2015 ◽  
Vol 29 (31) ◽  
pp. 1550222 ◽  
Author(s):  
E. Güler ◽  
M. Güler
Keyword(s):  
Phase Transition ◽  
Bismuth Telluride ◽  
Phonon Dispersion ◽  
Low Frequency ◽  
Theoretical Data ◽  
Interatomic Potentials ◽  
Transition Pressure ◽  
Theoretical Approaches ◽  
Phase Transition Pressure ◽  
Phonon Properties

Bismuth telluride (Bi2Te3) is one of the most intricate materials with its semiconducting, insulating and pressure-induced superconducting properties. Although different theoretical works have been carried out to understand the confusing properties of Bi2Te3, information about the high pressure structural, elastic, mechanical and phonon properties of this significant material is still rare. Unlike earlier theoretical approaches, two-body interatomic potentials in the Morse potential form have been employed for the first time to predict the density, phase transition pressure, elastic constants, bulk, shear and Young moduli and elastic wave velocities of Bi2Te3 under pressures up to 12 GPa. [Formula: see text] phase transition pressure of Bi2Te3 was found to be 10 GPa. The results of above elastic quantities agree well with experiments and are better than some of the published theoretical data. In addition, the effect of pressure on the phonon dispersion and density of states (DOS) were also evaluated with the same potential and their results are satisfactory, especially for the low-frequency acoustic portions of phonons.

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.

Pressure Effect on Structural and Phonon Properties of Mixed Alloys Compounds

2014 ◽  
Vol 1047 ◽  
pp. 85-93
Author(s):  
Ashok K. Ahirwar ◽  
Mahindra Aynyas ◽  
S.P. Sanyal
Keyword(s):  
Phase Transition ◽  
Debye Temperature ◽  
Phonon Dispersion ◽  
Structural Phase ◽  
Breathing Motion ◽  
Phase Transition Pressure ◽  
Volume Collapse ◽  
Experimental Findings ◽  
First Time ◽  
Phonon Properties

We report pressure induced structural phase transition, elastic and thermal properties of concentrations of UXLa1-XS (x= 0.80, 0.60 and 0.50) compound, using modified inter-ionic potential theory (MIPT), which parametrically includes the effect of coulomb screening. The calculated equation of state, phase transition pressure, bulk modulus and volume collapse are agree well with the available theoretical or experimental findings. We have also reported the second order elastic constants and Debye temperature of this compound for first time. We have also reported the Phonon properties of UxLa1-xS (x = 0.80, 0.60, 0.50) compounds by using breathing shell model (BSM). The present model includes breathing motion of electron shells of rare earth atom due to f-d hybridization. The calculated phonon dispersion curves of UxLa1-xS are presented follow the same trend as observed in uranium chalcogenides. We have reported doping effect of La on phonon frequencies at X and L-points for the first time. The LO-TO splitting increases as decreasing concentration of La.Keywords: Phase Transition, Elastic Properties, Debye Temperature, Phonon Dispersion

Mode-Wise Phonon Properties of Bismuth Telluride

2012 ◽  
Author(s):  
Yaguo Wang ◽  
Xianfan Xu
Keyword(s):  
Bismuth Telluride ◽  
Thermal Transport ◽  
Phonon Dispersion ◽  
Normal Mode Analysis ◽  
Relaxation Times ◽  
Mode Analysis ◽  
Phonon Modes ◽  
Time Resolved ◽  
Transport Control ◽  
Phonon Properties

Thermal transport properties and thermal transport control are important for many materials, for example, low thermal conductivity is desirable for thermoelectric materials. Knowledge of mode-wise phonon properties is crucial to identify dominant phonon modes for thermal transport and design effective phonon barriers for thermal transport control. In this paper, we adopt the normal mode analysis to investigate spectral phonon properties, and to calculate phonon dispersion relations and phonon relaxation times in bismuth telluride. Our results agree with previously reported data for long-wavelength longitudinal acoustic phonon and A1g optical phonon obtained from ultrafast time-resolved measurements. By combing the frequency dependent anharmonic phonon group velocities and lifetime, mode-wise thermal conductivities are predicted to reveal the contributions of heat carriers with different polarizations and wavelength.

PRESSURE INDUCED PHASE TRANSITION (B3–B1) AND ELASTIC PROPERTIES OF II–VI ZnSe SEMICONDUCTORS

2012 ◽  
Vol 26 (14) ◽  
pp. 1250077
Author(s):  
DINESH VARSHNEY
Keyword(s):  
Phase Transition ◽  
Nearest Neighbor ◽  
Electron Shell ◽  
Phenomenological Approach ◽  
Interionic Interaction ◽  
Transition Pressure ◽  
Phase Transition Pressure ◽  
Reported Data ◽  
Three Body ◽  
Vdw Interaction

We evolve an effective interionic interaction potential (EIoIP) to investigate the pressure induced phase transitions from Zinc blende (B3) to Rocksalt (B1) structure in ZnSe semiconductor. The developed potential consists of the long-range Coulomb and three-body interactions (TBI) and the Hafemeister and Flygare type short-range (SR) overlap repulsion extended upto the second neighbor ions and the van der Waals (vdW) interaction. The three-body interactions arise from the electron-shell deformation when the nearest-neighbor ions overlap and has been employed for detailed studies of pressure-induced phase-transition behavior of ZnSe semiconductors. Our calculated value of the phase transition pressure (Pt) is higher and the magnitude of the discontinuity in volume at the transition pressure is consistent with reported data. The variation of second-order elastic constants with pressure resembles that observed in some binary semiconductors. It is inferred that the vdW interaction is effective in obtaining the Debye temperature, Gruneisen parameter, thermal expansion coefficient and compressibility. It is argued that the model with TBI (model II) has yielded somewhat more realistic predictions of the phase-transition and high-pressure behavior as compared to usual two-body potentials (model I) based on phenomenological approach.

Mode-Wise Thermal Conductivity of Bismuth Telluride

2013 ◽  
Vol 135 (9) ◽  
Author(s):  
Yaguo Wang ◽  
Bo Qiu ◽  
Alan J. H. McGaughey ◽  
Xiulin Ruan ◽  
Xianfan Xu
Keyword(s):  
Thermal Conductivity ◽  
Bismuth Telluride ◽  
Thermal Transport ◽  
Phonon Dispersion ◽  
Relaxation Times ◽  
Phonon Modes ◽  
Time Resolved ◽  
Transport Control ◽  
Reported Data ◽  
Phonon Properties

Thermal properties and transport control are important for many applications, for example, low thermal conductivity is desirable for thermoelectrics. Knowledge of mode-wise phonon properties is crucial to identify dominant phonon modes for thermal transport and to design effective phonon barriers for thermal transport control. In this paper, we adopt time-domain (TD) and frequency-domain (FD) normal-mode analyses to investigate mode-wise phonon properties and to calculate phonon dispersion relations and phonon relaxation times in bismuth telluride. Our simulation results agree with the previously reported data obtained from ultrafast time-resolved measurements. By combining frequency-dependent anharmonic phonon group velocities and lifetimes, mode-wise thermal conductivities are predicted to reveal the contributions of heat carriers with different wavelengths and polarizations.

High Pressure Structural and Mechanical Properties of YBi and ScBi Compounds

2016 ◽  
Vol 1141 ◽  
pp. 39-43 ◽  
Author(s):  
Ashok K. Ahirwar ◽  
Mahendra Aynyas ◽  
Yeshvir Singh Panwar ◽  
Sankar P. Sanyal
Keyword(s):  
Phase Transition ◽  
Theoretical Study ◽  
Structural Phase ◽  
Theoretical Data ◽  
Second Order ◽  
Mechanical And Thermal Properties ◽  
First Order ◽  
Debye Temperatures ◽  
Phase Transition Pressure ◽  
Good Agreement

A theoretical study of first order pressure induced structural phase transition, mechanical and thermal properties of YBi and ScBi compounds have been investigated using the modified inter-ionic potential theory (MIPT), which parametrically includes the effect of coulomb screening. The calculated results of phase transition pressure of ScBi and YBi are agree well with the available theoretical data. We have also reported the second order elastic constants and Debye temperature of these compounds. Our calculated values of second order elastic constant C11, C12 and C44 are 128.4, 29.5, 30.2 GPa and 123.1, 29.7, 30.3 GPa for ScBi and YBi compounds respectively. These results are in good agreement with available theoretical data. We have also estimated Debye temperatures (θD) are 80K, 86K, for ScBi and YBi compounds respectively.

Sign in / Sign up

Export Citation Format

Share Document