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Phase transition

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Full-Text Articles in Physics

Pressure-Induced Structural Phase Transition And Electronic Structure Of In$_{1-X}$Ga$_{X}$P Alloys: A Dft Study, Kabita Khoirom, Indrajit Sharma, Brojen Singh, Ramkumar Thapa Jan 2019

Pressure-Induced Structural Phase Transition And Electronic Structure Of In$_{1-X}$Ga$_{X}$P Alloys: A Dft Study, Kabita Khoirom, Indrajit Sharma, Brojen Singh, Ramkumar Thapa

Turkish Journal of Physics

We present the density functional calculation to study the pressure-induced structural phase transition and electronic structure of In$_{1-x}$Ga$_{x}$P ($x =$ 0.0, 0.25, 0.5, 0.75, 1) alloys. We report the optimized structural parameters such as lattice constant, bulk modulus, and derivative of the bulk modulus of the alloys. Our calculation confirms that the alloys in the zinc-blende structure are more stable than in the rock-salt structure. The phase transition study from zinc-blende to rock-salt under pressure shows that the transition pressure increases with an increase in doping concentration. The energy band diagram of the alloys in the zinc-blende phase reveals a …


Magnetic Effect On The Phase Properties Of Neodymium-Activated Yttrium Disilicate Nanomaterials, Murat Erdem, Ci̇hat Boyraz Jan 2016

Magnetic Effect On The Phase Properties Of Neodymium-Activated Yttrium Disilicate Nanomaterials, Murat Erdem, Ci̇hat Boyraz

Turkish Journal of Physics

Under varying temperature conditions, undoped Y$_{2}$Si$_{2}$O$_{7}$ and neodymium-doped Y$_{2}$Si$_{2}$O$_{7}$ nanopowders were synthesized by the sol-gel method. The phase transitions from $\alpha $ to $\delta $ were observed in neodymium nanopowders by XRD measurements. TEM images showed ball-shaped structure forms for synthesized samples. The elemental compositions of all samples were established and quite close stoichiometry to all compound formulas was found using an attached component for TEM. To reveal the Nd dopant effect in different-phased Y$_{2}$Si$_{2}$O$_{7}$ nanopowders, diffuse reflectance measurements were conducted. To establish the magnetic properties of undoped Y$_{2}$Si$_{2}$O$_{7}$ and neodymium-doped Y$_{2}$Si$_{2}$O$_{7}$ nanopowders, an extensive study was carried out including …


Prediction Of The Pressure-Induced Phase Transition In Gaas By The Positron Affinity, Belabbes Soudini Jan 2009

Prediction Of The Pressure-Induced Phase Transition In Gaas By The Positron Affinity, Belabbes Soudini

Turkish Journal of Physics

The thermalized positron charge distribution is calculated as a function of pressure variation in GaAs. Calculations have been carried out via the independent particle method (IPM) coupled with the empirical pseudopotential method (EPM). Initial results show a clear asymmetrical positron charge distribution relative to the bond center. From this positron affinity we have calculated the ionicity character with respect to the pressure variation using our empirical formula. Our results show an agreement with the thermochemical phase diagram proposed by Phillips.


Heat Capacity Anomalies Of Tlins_2 And Tlgas_2 Single Crystals Detected By Differential Scanning Calorimetry (Dsc), Muhammed Açikgöz Jan 2008

Heat Capacity Anomalies Of Tlins_2 And Tlgas_2 Single Crystals Detected By Differential Scanning Calorimetry (Dsc), Muhammed Açikgöz

Turkish Journal of Physics

Specific heat capacity C_p anomalies of layered single crystals TlInS_2 and TlGaS_2 have been investigated using differential scanning calorimetry (DSC) as a new technique for such crystals. Special features of C_p have been revealed in the temperature range of the possible phase transitions of both crystals. A sequence of maximum values of C_p is obtained at 163, 174, 184, 193, 201, 212, 224, 254, and 259 K for TlInS_2. In the case of TlGaS_2, the temperatures of the obtained maximum C_p values at 177 and 241 K agree well with the intervals of the phase transition temperatures reported in the …


Pressure Induced Phase Transition In Monopnictides Cesb And Lasb, Sadhna Singh, Raja Chauhan, Atul Gour Jan 2008

Pressure Induced Phase Transition In Monopnictides Cesb And Lasb, Sadhna Singh, Raja Chauhan, Atul Gour

Turkish Journal of Physics

In the present paper, monopnictides of Ce and La, which crystallize in B_1 structure, have been studied using effective interaction potential (EIP) approach. The phase transition pressure and volume collapses for CeSb and LaSb predicted from this approach are found to be close to experimental data.


High-Pressure Phase Transition In Some Alkali Halides Using Interatomic Potential Model, Harun Reşi̇t Yazar Jan 2003

High-Pressure Phase Transition In Some Alkali Halides Using Interatomic Potential Model, Harun Reşi̇t Yazar

Turkish Journal of Physics

We have predicted the phase transition pressure in some alkali halides NaCl and KCl using an interatomic potential approach based on a rigid ion model. We have obtained phase transition pressures 28.69 and 2.4 GPa, respectively, and are in close agreement with their corresponding experimental transition pressures 29.0 and 2.0 GPa. This approach is promising with respect to the prediction of the phase transition pressures of other alkali halides.