相关论文: Enhancing the formation of ionic defects to study …
Proton ordering in water ice is a paradigmatic order-disorder transition in a locally constrained system. The ice rules require exactly two hydrogens close to each oxygen, restricting the disorder to an exponentially large yet strongly…
From high precision measurements of the complex dielectric constant of H2O ice, we identify the critical temperatures of the phase transition into and out of ice XI from ice Ih to occur at T_Ih-IX=58.9 K and T_IX-Ih=73.4 K. For D2O,…
We study the isotope effect on the temperature of the proton order/disorder phase transition between ice XI and ice Ih, using the quasiharmonic approximation combined with \textit{ab initio} density functional theory calculations. We show…
We study the phase equilibrium between liquid water and ice Ih modeled by the TIP4P/Ice interatomic potential using enhanced sampling molecular dynamics simulations. Our approach is based on the calculation of ice Ih-liquid free energy…
Ordinary ice has a proton-disordered phase which is kinetically metastable, unable to reach, spontaneously, the ferroelectric (FE) ground state at low temperature where a residual Pauling entropy persists. Upon light doping with KOH at low…
We discuss the problem of proton motion in Hydrogen bond materials with special focus on ice. We show that phenomenological models proposed in the past for the study of ice can be recast in terms of microscopic models in close relationship…
Ice Ih has been studied by path-integral molecular dynamics simulations, using the effective q-TIP4P/F potential model for flexible water. This has allowed us to analyze finite-temperature quantum effects in this solid phase from 25 to 300…
It has been known since the pioneering work of Bernal, Fowler and Pauling that common, hexagonal (Ih) water ice is the archetype of a frustrated material : a proton-bonded network in which protons satisfy strong local constraints - the "ice…
We demonstrate a novel method to ionize molecules or molecular clusters by proton transfer at temperatures below 1 K. The method yields nascent ions and largely eliminates secondary reactions, even for notoriously "delicate" molecules.…
We use electron momentum density in ice as a tool to quantify order-disorder transitions by comparing Compton profiles differences of ice VI, VII, VIII and XII with respect to ice Ih. Quantitative agreement is found between theory and…
Doping the hydrogen-disordered phases of ice V, VI and XII with hydrochloric acid (HCl) has led to the discovery of their hydrogen-ordered counterparts ices XIII, XV and XIV. Yet, the mechanistic details of the hydrogen-ordering phase…
Under cold compression, hydrogen bonding was considered to dominate intermolecular interaction during the ionization of ammonia. Here, we provide experimental and theoretical evidence of intermolecular HH coupling in dense ammonia. Ab…
The kinetic energy of H and O nuclei has been studied by path integral molecular dynamics simulations of ice Ih and water at ambient pressure. The simulations were performed by using the q-TIP4P/F model, a point charge empirical potential…
We have investigated the thermally induced proton/deuteron exchange in mixed amorphous H$_2$O:D$_2$O ices by monitoring the change in intensity of characteristic vibrational bending modes of H$_2$O, HDO, and D$_2$O with time and as function…
We investigated the influence of doping antiferromagnetic MnN in polycrystalline MnN/CoFe exchange bias systems, showing high exchange bias of up to 1800 Oe at room temperature. The thermal stability of those systems is limited by nitrogen…
The amorphous conducting carbon films have been prepared at three different preparation temperatures with different boron-doping levels. The structural and transport properties of the same have been studied. X-ray diffraction measurements…
Using molecular dynamics simulations and methods of importance sampling, we study the thermodynamics and dynamics of sodium chloride in the aqueous premelting layer formed spontaneously at the interface between ice and its vapor. We uncover…
We employ classical molecular dynamics simulations to investigate the molecular-level structure of water during the isothermal compression of hexagonal ice (I$h$) and low-density amorphous (LDA) ice at low temperatures. In both cases, the…
The isotope effect in the melting temperature of ice Ih has been studied by free energy calculations within the path integral formulation of statistical mechanics. Free energy differences between isotopes are related to the dependence of…
The phase diagram of ice Ih, II, and III is studied by a quasi-harmonic approximation. The results of this approach are compared to phase diagrams previously derived by thermodynamic integration using path integral and classical…