Related papers: The Effect of Pressure on the Negative Thermal Exp…
The thermal expansion at constant pressure of solid CD$_4$ III is calculated for the low temperature region where only the rotational tunneling modes are essential and the effect of phonons and librons can be neglected. It is found that in…
Using the non-empirical Variational Induced Breathing (VIB) model, the thermal properties of periclase (MgO) under high pressures and temperatures are investigated using molecular dynamics, which includes all anharmonic effects. Equations…
We report a hierarchical first-principles investigation on the entangled effects of lattice dimensionality and bond characteristics in the lattice dynamics of silicene and germanene. It is found that bond bending (stretching) negatively…
Proceeding from the model of a two-dimensional elastic continuum, we describe the characteristic features of thermal expansion of graphene using an approach that goes beyond the quasi-harmonic approximation. The negative value of the…
Pressure and temperature dependence of the negative thermal expansion in Zn(CN)$_2$ is fully investigated using molecular dynamics simulations with a built potential model. The advantage of this study allows us to reproduce all the exotic…
The thermal expansion coefficient $\alpha$ of MgB$_2$ is revealed to change from positive to negative on cooling through the superconducting transition temperature $T_c$. The Gr\"uneisen function also becomes negative at $T_c$ followed by a…
Motivated by the negative thermal expansion observed for silicon between 20 K and 120 K, we present first an ab initio study of the volume dependence of interatomic force constants, phonon frequencies of TA(X) and TA(L) modes, and of the…
We investigated pressure effects on the nontrivial heavy-fermion antiferromagnet CeMnSi by means of electrical resistivity and powder X-ray diffraction. With increasing pressure, the antiferromagnetic order of Mn (T_N ~ 240 K at ambient…
Using a realistic model, the mode Gruneisen parameters and the temperature dependent coefficient of linear thermal expansion are calculated for amorphous silicon. The resulting values of the Gruneisen parameters differ from the crystalline…
We use a combination of variable-temperature / variable-pressure neutron powder diffraction, variable-pressure inelastic neutron scattering, and quantum chemical calculations to interrogate the behaviour of the negative thermal expansion…
We consider the thermal expansion, change of sound velocity with pressure and temperature, and the Poisson ratio of lattices which have rigid units (polyhedra very large stiffness to change in bond-length and to bond-angle variations)…
We investigate the effect of hydrostatic pressure on temperature dependence of magnetization and also the influence of magnetic field on linear thermal expansion in polycrystalline Pr0.6Sr0.4MnO3, which is ferromagnetic at room temperature…
The thermal expansion effect of silicon nanowires (SiNW) in [100], [110] and [111] directions with different sizes is theoretically investigated. At low temperatures, all SiNW studied exhibit thermal contraction effect due to the lowest…
Thermal properties of graphene display peculiar characteristics associated to the two-dimensional nature of this crystalline membrane. These properties can be changed and tuned in the presence of applied stresses, both tensile and…
The effect of pressure on structural and thermodynamic properties of ice Ih has been studied by means of path-integral molecular dynamics simulations at temperatures between 50 and 300 K. Interatomic interactions were modeled by using the…
The common wisdom that volume decreases with pressure and increases with temperature is analyzed in terms of Hillert nonequilibrium thermodynamics in the present work. It is shown that the derivative of volume to pressure in a stable system…
We investigate the temperature dependence of the pressure-induced softening in the negative thermal expansion material Zn(CN)$_2$ using neutron powder diffraction and molecular dynamics simulations. Both the simulation and experiment show…
Design and operation of advanced reactors such as fuel reformers require reliable micro-kinetic models that capture the dynamics of the reaction. The negative temperature coefficient phenomenon causes a reduction in mixture temperature for…
The effect of undrained heating on volume change and induced pore pressure increase is an important point to properly understand the behaviour and evaluate the integrity of an oil well cement sheath submitted to rapid temperature changes.…
Studies of the mechanical properties of single-walled carbon nanotubes are hindered by the availability only of ensembles of tubes with a range of diameters. Tunable Raman excitation spectroscopy picks out identifiable tubes. Under high…