Carbides have attracted much attention owing to their interesting physical and chemical properties. Here, we systematically investigated global energetically stable structures of BeC2 in the pressure range of 0-100 GPa using a first-principles structural search. A transition from the ambient-pressure α-phase to the high-pressure β-phase was theoretically predicted. Chemical bonding analysis rev...

The electronic structures of the early transition metals are characterised by the relationship that exists between the occupied narrow d bands and the broad sp bands. Under pressure, the sp bands rise faster in energy, causing electrons to be transferred to the d bands (Gupta et al., 2008). This process is known as the s-d transition and it governs the structural properties of the transition me...

We use the thermodynamic model introduced by Aptekar’ and Ponyatovskiy for the – transformation in cerium metal to study the properties f plutonium metal. The model describes the – transformation in Pu and explains the minimum in the melting versus pressure curves for both aterials. Ga stabilization of the -phase of Pu is explained in terms of a first order transition between the two phases. Th...

The pressure-induced phase transition in GaAs is studied using an ab initio constant-pressure relaxation simulation. GaAs undergoes a first-order phase transition to Cmcm at 54 GPa. Upon further increase of pressure a gradual phase change to Imm2 structure is seen at 57 GPa, which confirms an earlier experiment and clears some doubts about the existence and identity of Imm2. The transition pres...

in the present research, in contrast to the available papers, not only the superelasticity but also the shape memory effects are taken into account in determination of the impact responses. at the same time, in addition to modifying brinson’s model for the shape memory alloys (smas), to include new parameters and loading events, and hertz contact law, distributions of the sma phases are conside...

copper sulphide (cu 2 s) thin films at different thicknesses and annealing temperatures were deposited onto glass substrate by vacuum evaporation method. xrd study reveals the phase transformation of cu     2 s film at higher thickness. optical and resistivity study show the phase transformation of the film from cu     2 s to cus when they are annealed at higher temperature. sem st...

Recent experiments have shown that the perovskite to post-perovskite phase transformation in CaIrO3 occurs more readily at room temperature when a shear stress is applied as compared to isotropic pressure. To understand this mechanistically, we have calculated the minimum-energy pathway of the phase transition with density functional theory under different pressure conditions with the generaliz...

sible supercells of and ! to determine the lattice strain exact energy barrier. The TB-NEB barrier is bounded Martensitic transformations are abundant in nature and are commonly used in engineering technologies [1]. Materials from steel to shape-memory alloys are governed by their underlying martensitic transformations [2]. The pressure driven hcp ! ! hexagonal transformation in pure titanium [...

This paper describes time-resolved x-ray diffraction data monitoring the transformation of one inverse bicontinuous cubic mesophase into another, in a hydrated lipid system. The first section of the paper describes a mechanism for the transformation that conserves the topology of the bilayer, based on the work of Charvolin and Sadoc, Fogden and Hyde, and Benedicto and O'Brien in this area. We s...