Related papers: Lindeman's criterion: diamond graphitization tempe…
The emission intensity of diamond samples containing nitrogen-vacancy centres are measured as a function of magnetic field along a <111> direction for various temperatures. At low temperatures the responses are sample and stress dependent…
We present a comprehensive study of the temperature and magnetic-field dependent photoluminescence (PL) of individual NV centers in diamond, spanning the temperature-range from cryogenic to ambient conditions. We directly observe the…
A sweep through a quantum phase transition by means of a time-dependent external parameter (e.g., pressure) entails non-equilibrium phenomena associated with a break-down of adiabaticity: At the critical point, the energy gap vanishes and…
Temperature fluctuations in the normal direction of planar crystals such as graphene are quite violent and may be expected to influence strongly their melting properties. In particular, they will modify the Lindemann melting criterium. We…
A simple description of thermodynamics of DMAAS and DMAGaS ferroelectric crystals by means of Landau expansion is proposed. Conditions of occurrence of phase transitions are established and their temperatures are obtained. The influence of…
Electrical resistivity and ac-susceptibility measurements under high pressure were carried out in high-quality single crystals of $\alpha$-Mn. The pressure-temperature phase diagram consists of an antiferromagnetic ordered phase (0<$P$<1.4…
The direct graphite-to-diamond transformation mechanism has been a subject of intense study and remains debated concerning the initial stages of the conversion, the intermediate phases, and their transformation pathways. Here, we…
The effects of flexibility and chemical composition in the variation of the glass transition temperature are obtained by using the Lindemann criteria, that relates melting temperature with atomic vibrations. Using this criteria and that…
The pressure-induced structural transition in fcc C$_{60}$ fullerene by shock compression and rapid quenching is investigated by a semi-empirical tight-binding molecular dynamics simulation, adopting a constant-pressure scheme and a method…
Solidification as a first order phase transition is described in the Landau theory by the same equation as tricritical phenomena. Here, the solidification or melting temperature against pressure curve is modelled to end at a tricritical…
We consider interaction effects in a granular normal metal at not very low temperatures. Assuming that all weak localization effects are suppressed by the temperature we replace the initial Hamiltonian by a proper functional of phases and…
Diamond is studied by path integral molecular dynamics simulations of the atomic nuclei in combination with a tight-binding Hamiltonian to describe its electronic structure and total energy. This approach allows us to quantify the influence…
We first consider the recrystallization characteristics of catalysis alloy and graphite in the process of diamond synthesis under the condition of super high pressure and high temperature in catalysis method. In the process of diamond…
We show by means of molecular dynamics simulations that graphene is an excellent coating for diamond. The transformation of diamond to amorphous carbon while sliding under pressure can be prevented by having at least two graphene layers…
We investigated the electronic and vibrational properties of magnetite at temperatures from 300 K down to 10 K and for pressures up to 10 GPa by far-infrared reflectivity measurements. The Verwey transition is manifested by a drastic…
Soft x-rays were applied to induce graphitization of diamond through a non-thermal solid-to-solid phase transition. This process was observed within poly-crystalline diamond with a time-resolved experiment using ultrashort soft x-ray pulses…
Diamonds melt at temperatures above 4000 K. There are no measurements of the steady-state rate of the reverse process: diamond nucleation from the melt, because experiments are difficult at these extreme temperatures and pressures. Using…
At high pressure, the typical behavior of elements dictated by the periodic table - including oxidation numbers, stoichiometries in compounds, and reactivity, to name but a few - is altered dramatically. As pressure is applied, the…
We present a non mean-field model which undergoes a magnetostriction phase transition in the temperature. That is, the crystal becomes sharply contracted and magnetized once the temperature passes below the critical value
The pressure evolution of the Raman spectrum of graphene grown by chemical vapour deposition on polycrystalline copper is investigated with the use of a polar and a non-polar pressure transmitting medium (PTM). The G and 2D Raman bands…