scholarly journals Role of temperature in the numerical analysis of CaO under high pressure

2010 ◽  
Vol 8 (1) ◽  
pp. 126-133 ◽  
Author(s):  
Purvee Bhardwaj ◽  
Sadhna Singh
Keyword(s):  
Phase Transition ◽  
High Pressure ◽  
Numerical Analysis ◽  
Thermodynamic Properties ◽  
Elastic Constants ◽  
Volume Change ◽  
Thermodynamical Properties ◽  
Phase Transition Pressure ◽  
Different Temperatures

AbstractIn this paper we focus on the elastic and thermodynamic properties of the B1 phase of CaO by using the modified TBP model, including the role of temperature. We have successfully obtained the phase transition pressure and volume change at different temperatures. In addition elastic constants and bulk modulus of B1 phase of CaO at different temperatures are discussed. Our results are comparable with the previous ones at high temperatures and pressures. The thermodynamical properties of the B1 phase of CaO are also predicted.

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.

Pressure Induced Properties of UXLa1-XS Compound

2016 ◽  
Vol 28 ◽  
pp. 108-114
Author(s):  
Ashok K. Ahirwar ◽  
Mahendra Aynyas ◽  
Sankar P. Sanyal
Keyword(s):  
Experimental Data ◽  
Phase Transition ◽  
Thermal Properties ◽  
Bulk Modulus ◽  
Debye Temperature ◽  
Elastic Constants ◽  
Volume Change ◽  
Mechanical And Thermal Properties ◽  
Phase Transition Pressure ◽  
Crystal Structural

The crystal structural, mechanical and thermal properties of UXLa1-XS compound with different concentrations (x= 0.00, 0.08 and 0.40) are investigated using modified inter-ionic potential theory (MIPT), which parametrically includes the effect of coulomb screening by the delocalized f-electrons. Our calculated values of phase transition pressure, bulk modulus and volume change are agree well with the theoretical and experimental data. We have also calculated the second order elastic constants and Debye temperature of these three concentrations.

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