Melting curve and phase diagram of ammonia monohydrate at high pressure and temperature

The phase diagram of trans-4-n-hexyl-(4'-cyanophenyl)-cyclohexane, (6PCH) has been established by high-pressure differential thermal analysis. Specific volumes are presented for temperatures between 300 and 370 K up to 300 MPa. The p,Vm ,T data have been determined for the nematic, isotropic, and (partly, in the neighbourhood to the melting curve) solid phases. Volume and enthalpy changes along the phase transitions have also been calculated. As previously, the p,Vm,T data were used to calculate the volume entropy for the nematic-isotropic transition. The molar volumes along the clearing line TNI (p) enabled us to calculate the molecular field parameter γ = ∂ln TNI/∂In VNI , being 4.1.

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Unexpected coordination number and phase diagram of niobium diselenide under compression

Physical Chemistry Chemical Physics ◽

10.1039/c7cp00805h ◽

2017 ◽

Vol 19 (20) ◽

pp. 13219-13229 ◽

Cited By ~ 4

Author(s):

Zhong-Li Liu ◽

Hong Jia ◽

Rui Li ◽

Xiu-Lu Zhang ◽

Ling-Cang Cai

Keyword(s):

Phase Diagram ◽

High Pressure ◽

Coordination Number ◽

Harmonic Approximation ◽

Temperature Phase ◽

High Pressure And Temperature ◽

Niobium Diselenide ◽

Temperature Phase Diagram

We discovered several new high-pressure structures of NbSe2 with unexpected coordination number and constructed its high pressure and temperature phase diagram based on quasi-harmonic approximation.

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Melting curve and phase diagram of vanadium under high-pressure and high-temperature conditions

Physical Review B ◽

10.1103/physrevb.100.094111 ◽

2019 ◽

Vol 100 (9) ◽

Cited By ~ 13

Author(s):

D. Errandonea ◽

S. G. MacLeod ◽

L. Burakovsky ◽

D. Santamaria-Perez ◽

J. E. Proctor ◽

...

Keyword(s):

Phase Diagram ◽

High Pressure ◽

High Temperature ◽

Melting Curve ◽

Temperature Conditions

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Phase transition and thermodynamic properties of beryllium telluride under high pressure

International Journal of Modern Physics B ◽

10.1142/s0217979215500964 ◽

2015 ◽

Vol 29 (15) ◽

pp. 1550096

Author(s):

Zhi-Cheng Guo ◽

Fen Luo ◽

Xiu-Lu Zhang ◽

Cheng-An Liu ◽

Ling-Cang Cai

Keyword(s):

Phase Diagram ◽

High Pressure ◽

Thermodynamic Properties ◽

Density Functional ◽

Phonon Dispersion ◽

Structural Parameters ◽

Theoretical Work ◽

Debye Model ◽

Dielectric Tensor ◽

High Pressure And Temperature

A theoretical investigation on structural, dynamical, phase diagram and thermodynamic properties of beryllium telluride (BeTe) under high pressure and temperature is presented in the framework of density functional theory. The calculated structural parameters of BeTe in both zinc blende (ZB) and nickel arsenide (NiAs) structures are in reasonable agreement with available experimental data and previous theoretical work. The phonon dispersion relations, dielectric tensor and Born effective charge are investigated within the density functional perturbation theory (DFPT). The investigation of the phase diagram indicated that the NiAs structure BeTe becomes stable at high pressure and temperature. Based on the quasiharmonic Debye model, the pressure and temperature dependences of bulk modulus, Grüneisen parameter, Debye temperature, specific heat and thermal expansion coefficient are all successfully obtained. We hope that the theoretical results reported here can give more insight into the structural and thermodynamic properties of other semiconductors at high temperature and pressure.

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