Effect of boundary conditions on the character of ambipolar diffusion in electrolytes

PREInternational audienceWe discuss the details of ambipolar relaxation of the electric field in liquid asymmetric electrolytes to its stationary value. It is demonstrated that the account for finite boundary conditions modifies the existing concepts of this diffusion process. In particular, we succeeded to suggest a qualitatively correct explanation of the observed distribution of the electric fields over the bulk of the cuvette and its nonmonotonic behavior in measurements on the finite-size cuvette. We analyze the conditions of such an anomaly at the intermediate stages of the relaxation proces

On dissociation in weakly doped ice

Currently, there is some ambiguity in the problem of decay of a single donor into charged fragments. Thus, in the well-known Ostwald approximation used for semiconductors (ice being one of them) the donor dissociation degree of tends to its maximum value (i.e., unity) as the doping impurity concentration approaches zero. At the same time, the statistical theory of atom reveals within the Thomas–Fermi (or Debye–Hückel) approximation the existence of a thermodynamically equilibrium state of a single multi-electron atom (donor) where charged nucleus keeps the number of counterions just necessary for its neutralization. These scenarios do not show the atom dissociation at all. Discussed in the present paper is the alternative between the full dissociation of a single donor (i.e., dissociation degree equals unity) in a semiconducting media (ice, water, semiconductor) and zero dissociation degree

Эффекты близости в холодном газе многозарядных атомов (Обзор)

Обсуждаются возможные эффекты близости в газе холодных многозарядных атомов. Речь идет о разреженном газе плотностью dn тяжелых атомов (Z >> 1) при низких температурах в рамках известного приближения Томаса–Ферми (TF), дающего возможность судить о статистических свойствах отдельного атома.Обговорюються можливі ефекти близькості в газі холодних багатозарядних атомів. Йдеться про розріджений газ щільностью nd важких атомів (Z >> 1) при низьких температурах в рамках відомого наближення Томаса–Фермі (TF), що дає можливість судити про статистичні властивості окремого атома.Possible proximity effects in gases of cold, multiply charged atoms are discussed. Here we deal with rarefied gases with densities nd of multiply charged ( Z ≫ 1) atoms at low temperatures in the well-known Thomas-Fermi (TF) approximation, which can be used to evaluate the statistical properties of single atoms

Mechanisms of self-screening in pure ice

Possible approaches to a correct account of the Coulomb interaction in system of proton-hydroxyl pairs in pure ice (a proton version of intrinsic semiconductor) are discussed for a possibility to evaluate correlation properties of semiconducting media

Relaxation phenomena in cryogenic electrolytes

Proposed is a scenario for development of observed relaxation phenomena in the cryogenic electrolyte with the structure of “liquid hydrogen + injected ions”. Ions of one sign are generated in the bulk of liquid hydrogen in the presence of external field E⊥ by a stationary radioactive source of ± ions at the bottom of the vessel. After accumulation near the free surface of the liquid with a finite density ns the ions can break its stability producing a pulse of ion current to the collector located above the liquid surface. The outlined process is periodically repeated. Its period contains information on the ion mobility and, which is most interesting, on dissociation (association) processes occurring in a system of charged particles placed in an external field. The cryogenic problem is a good model for dissociation in the presence of external field occurring in normal electrolytes without any external ion sources

Charged snowball in nonpolar liquid

The problem of correct definition of the charge carrier effective mass in superfluid helium is revised. It is demonstrated that the effective mass M of a such quasiparticle can be introduced without use of the Atkins’s idea concerning the solidification of liquid He in the close vicinity of ion. The two-liquid scenario of the «snowball» mass formation is investigated. The normal fluid contribution to the total snowball effective mass, the physical reasons of its singularity and the way of corresponding regularization procedure are discussed. Within of two-liquid model the existence of two different effective snowball radiuses: Rid for superfluid flow component and Rn for the normal one, Rn > Rid is demonstrated. Agreement of the theory with the available experimental data is found

Dynamic phenomena for charged clusters in cryogenic liquids

Discussed in the paper are resonance phenomena in electrolytes related to possible relative motion of the charged core and hydrate (solvate) shell of each cluster. The resonances are shown to contain important information on the internal structure of clusters. Special attention is paid to the process of formation of the cluster associated mass in the solvent

Cryogenic electrolytes

The emphasis is made on experimentally observed indications of the presence of metastable ion dipoles in solid helium. Similar quasiparticles possessing positive scattering length for injected electrons are assumed to exist in liquid phases of cryogenic liquids. The observed phenomena allowing to detect and monitor the behavior of dipole gas in superfluid helium (referred to as cryogenic electrolyte) are discussed. Most interesting among these phenomena are: special features of the dielectric behavior of ion dipole gas, details of the temperature dependence of the ion dipole gas osmotic pressure at the boundary of the liquid ³He–⁴He solution stratification, relaxation phenomena of collective origin in cryogenic electrolytes, and liquid helium phonon spectrum transformation due to strong interaction between phonons and heavy dipole quasiparticles