Solid Mercury Research Articles

Dominance of Linear 2-Coordination in Mercury Chemistry: Quasirelativistic and Nonrelativistic ab Initio Pseudopotential Study of (HgX2)2 (X = F, Cl, Br, I, H)

The preference of many solid mercury compounds for «molecular» structures with lower characteristic coordination numbers (frequently CN=2) and lower boiling points than the corresponding zinc or cadmium species is due to relativistic effects. In particular, the relativistic increase of the mercury 6s-orbital ionization energies reduces the charge separation in and the intermolecular interactions between HgX 2 molecules containing electronegative substituents X. These are the major conclusions of extensive quasirelativistic and nonrelativistic ab initio pseudopotential Hartree-Fock and MP2 calculations on the dimeric systems (HgX 2 ) 2 (X=F, Cl, Br, I, H) and on the HgX 2 monomers

Possible origin of the sharp drops of resistivity around 250 K in superconducting Hg-compounds

The resistivity transitions and sometimes the loss of resistance at about 235 K of the superconducting Hg-based cuprates synthesized under high pressure reported by Tholence et al. [Phys. Lett. A 184 (1994) 215] can be considered to come from the freezing of traces of mercury in the samples when the solid mercury forms a current percolation net which gives a very low measured resistivity that lies within the conventional experimental errors.

Atomic absorption: another way for phase transition characterization

Phase transitions ocurring in compounds present at ppm levels in powders can be qualitatively and quantitatively observed by atomic absorption spectrometry. Thermodynamic and kinetic aspects of atomic vapour formation during a phase transition are considered. A first generation apparatus for phase transition characterization by atomic absorption spectrometry (PTCAAS) measurements by a fluidized bed technique is presented. As a typical application of this new technique, the determination of ppm amounts of a mixture of mercury(I) and mercury(II) salts in sodium iodide is discussed. The PTCAAS method allows thermal analysis of minor components present in powdered mixtures or as surface layers on solid substrates. By these means one can often obtain data concerning physical state, oxidization state and behaviour during reactions or near equilibrium conditions of low concentration species, for which usual thermal analysis, X ray diffraction or electron microprobe techniques become ineffective. Thus, it could be shown that drying a molar solution of sodium iodide containing less than 10 ppm of sodium iodomercurate results in the formation of solid mercury(I) iodide and correlated destruction of the mercurate complex.

Electrodeposition of alkali metals on solid and liquid mercury electrodes

Electrodeposition of alkali metals on Hg/Au electrodes from non-aqueous solutions was studied using cyclic voltammetry and chronoamperometry. At temperatures of 20 to − 70°C the formation of bulk intermetallic compounds preceded by nucleation phenomena was observed. Stoichiometry of the solid phases formed under these conditions was determined. At very low temperatures, when the mobility of mercury atoms was restricted, the underpotential deposition of alkali metal ions on solid mercury electrodes was noted. The Gibbs energies of electrosorption are discussed in terms of interactions between alkali metals and mercury.

Calculation of thermodynamic data from voltammetry of solid lead and mercury dithiocarbamate complexes mechanically attached to a graphite electrode

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCalculation of thermodynamic data from voltammetry of solid lead and mercury dithiocarbamate complexes mechanically attached to a graphite electrodeAlan M. Bond and Fritz ScholzCite this: J. Phys. Chem. 1991, 95, 19, 7460–7465Publication Date (Print):September 1, 1991Publication History Published online1 May 2002Published inissue 1 September 1991https://doi.org/10.1021/j100172a063RIGHTS & PERMISSIONSArticle Views159Altmetric-Citations28LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (713 KB) Get e-Alerts

Positron annihilation study of defects in solid mercury

Solid mercury samples were deformed at liquid nitrogen temperature. The annealing of the induced defects was monitored with positron annihilation S-parameters. The order of magnitude of the activation energy for the migration of the dislocations was determined by means of the “cross cut of curves” method, and found to be 0.10±0.07 eV.

Flow-injection spectrophotometric determination of chloride with an on-line solid mercury(II) thiocyanate minicolumn and bromide with a silver thiocyanate minicolumn

Flow-injection spectrophotometric procedures are described for the determination of chloride and bromide using on-line solid mercury(II) thiocyanate and silver thiocyanate minicolumns, respectively. The linear response ranges for chloride and bromide are 0.28 × 10 −4−8.5 × 10 −4 M and 0.38 × 10 −4−2.4 × 10 −4 M, respectively. The sample throughput for both systems is 100 h −1. The lifetime of the minicolumns is 50 and 200 injections, respectively.

Direct combination of thermogravimetric analyser and atomic absorption spectrometer for detection of atomic vapour in thermal analysis

A thermogravimeter was combined with an atomic absorption spectrometer. The atomic absorption could be measured simultaneously with the thermogravimetrical changes under identical conditions. Optimum experimental conditions were determined using solid mercury halides and mercury(II) nitrate, by varying the sample weight and the flow rate of the carrier gas. The absorbance versus temperature curves obtained with this system for mercury halides and nitrate are compared with the corresponding thermograms. This apparatus may be useful in obtaining much more information concerning the gases evolved in thermogravimetry and the atomization processes of many metal-containing substances in atomic absorption spectrometry.

Allium micronucleus (MNC) assay to assess bioavailability, bioconcentration and genotoxicity of mercury from solid waste deposits of a chloralkali plant, and antagonism of l-cysteine

Samples of solid waste from a chloralkali plant were bioassayed employing the Allium micronucleus (MNC) assay. The endpoints measured were root length, root mercury and frequency of root meristematic cells with MNC. Chemical extraction methods such as 10% HNO 3, ammonium acetate-EDTA and 0.05 or 0.1 M CaCl 2 were used to assess the bioavailability of mercury from soil contaminated with solid waste. Analysis of mercury was by cold vapour atomic absorption spectrophotometry. The frequency of MNC induced by contaminated soil, which followed a concentration-response curve, was statistically correlated with soil mercury, extractable mercury and root mercury. The antagonism of l-cysteine against the suppression of root growth and induction of MNC by solid waste suggested the involvement of mercury as well as thiol groups in the process. The threshold assessment values, such as the median effective concentration (EC 50) for root growth, gross toxicity concentration tested (GTCT) as indicated by complete inhibition of sprouting of roots, lowest effective concentration tested (LECT) and highest ineffective concentration tested (HICT) for induction of MNC, were determined. These assessment values may be useful for environmental management and regulatory purposes. Furthermore, the detection limit of the Allium MNC assay for solid waste mercury as indicated by LECT was 9.6 mg kg −1 which corresponded to 0.13 mg kg −1 of 0.05 M CaCl 2 extractable or 8.3 mg kg −1 dry weight bioconcentrated mercury.

Thermodynamic properties of solid mercury from 150 to 234 K

The heat capacity of a mercury sample with less than 2×10 −4 mass per cent of impurities has been investigated over the temperature range 150.90 to 233.79 K. Two temperature regions, each with different behaviour of the temperature dependence of the heat capacity, have been discovered in this range. The results obtained over the range closer to the melting temperature are in good agreement with those obtained from the quasi-crystalline-melting theory.

Cryogenic temperature mechanical behavior of solid mercury

Tensile mechanical behavior of as-cast solid mercury which is relevant to Josephson integrated circuit packaging applications has been studied at 77 K and between 4.2 and 20 K. It was found that solid mercury is ductile, particularly so at temperatures close to 4.2 K. Further, at and near 4.2 K solid mercury exhibits pronounced work hardening, high tensile strength, and markedly serrated flow behavior. A possible explanation of these observations is presented, based on existing information on deformation and transformation characteristics of mercury at cryogenic temperatures.

Differential thermal analysis of linear chain mercury compounds

Differential thermal analysis of powders and single crystals of Hg3-δAsF6 is reported for the temperature interval 100 to 500 K. There is an endotherm at 234 K, corresponding to the melting of mercury during warming, but no exotherm at this temperature during cooling. The amount of mercury detected during warming is 1.3 ± 0.4% of the mercury in a sample. This is greater than the amount of mercury expected from simple contraction of the lattice from room temperature. These results are explained by the presence of a phase of dispersed, solid mercury in the sample. Mercury is formed at the order–disorder transition of the mercury chains and melts at 235 K. Mercury in samples with some decomposition showed a freezing exotherm after supercooling at 18 K. There is irreversible thermal decomposition of Hg3-δAsF6 above 400 K.

塩化ナトリウム水溶液への酸化水銀 (II) の光可溶化について

Mercury (II) Oxide suspended in sodium chloride solution is in equilibrium between the solid Mercury (II) oxide and dissolved mercury (II) chloride. When the suspension was irradiated using a blacklight lamp, the mercury (II) oxide dissolved rapidly with sodium chloride concentration increase and a trace of mercury (I) chloride was produced.

Simultaneous melting and freezing in the impingement region of a liquid jet

AbstractAn experimental investigation of an impinging water jet freezing on a melting solid surface has been carried out. Attention was focused on the stagnation region of an axisymmetric jet. In the experiment, a water jet was directed upward against the lower end of a meltable rod, having a diameter about twice that of the jet orifice. Solid octane (m.p.—56.5°C) and solid mercury (m.p.—38.9°C) served as the meltable materials. A laminar‐axisymmetric flow model was developed to describe melting heat transfer in the presence of jet solidification within the impingement region. Measurements of the melting rate and conditions for the onset of jet solidification were found to agree quite well with the values predicted with this model.

Dust in dental laboratories. Part I: Types and levels in specific operations

The types and levels of dust in breathing air close to the workpiece produced through cutting, grinding, or polishing of alloys in dental laboratories have been characterized. The dust levels were compared with threshold limit values (TWA or STEL). In laboratories with improper local ventilation systems, dust levels considerably exceeding such values were recorded. Levels in excess of 10 times the threshold limit values were observed for solid mercury and silver present in amalgam dust, for cobalt present in nonprecious alloys, and for gypsum. Silver exceeded the threshold limit value 1,750 times in one case. Moderate excess of threshold limit values, that is less than 10 times, were measured for copper, nickel, tin, and porcelain in cases of insufficient ventilation. With the efficient outlet systems available on the commercial market, the dust levels could be reduced to levels consistent with criteria of threshold limit values except when trimming amalgam dies. Such systems comprise tubes with diameters of 35 mm connected to pumps with suction capacities of about 30 l/sec.

Determination of total particulate mercury in air with the coleman mercury analyzer system

A simple and rapid cold-vapour atomic absorption system is described for the simultaneous determination of low ambient levels of particulate mercury and volatile mercury compounds. Of the different filters checked for particle collection, quartz fibre filters have the best properties. Sampling characteristics were considered with respect to efficiency, reproducibility and duration of sampling. The homogeneity of the solid mercury deposit on the filter was tested. Possible enrichment during sampling by absorption of volatile mercury compounds and possible mercury losses by volatilization of solid compounds were examined. After sampling the mercury is released by pyrolysis and collected on a gold-coated sand absorber. In order to avoid deactivation of the absorber by condensation of pyrolysis products or interference during the subsequent dcsorption and atomic absorption measurement of the collected mercury, a heated catalytic convertor and two specific absorbers for organic substances are inserted in the analysis line.

Resistivity of solid mercury

The resistivity ratio of polycrystalline pure mercury is obtained over the temperature range 1.65 to 234 K. At temperatures below 3 K this ratio is proportional to T 5 and above 50 K to T. Measurements of magnetoresistance extrapolated to zero field are used below 4.2 K. At intermediate temperatures the data may be fit using the Gruneisen-Bloch equation with a characteristic temperature of 35 K. Corrections for resistivity at constant volume and size effects are discussed.

Direct analysis of solid cadmium mercury telluride by flameless atomic absorption using interactive computer processing

This paper describes a solid sampling technique for the quantitative measurement of impurities in cadmium mercury telluride (CMT) in the ppb region. It has been used to calibrate the spark source mass spectrograph (A.E.I. MS7) analysis of this material. Typical detection limits obtained are: 0.0002 ppmw Ag, 0.002 ppmw Cu, 0.001 ppmw Fe, 0.0002 ppmw Mn, 0.002 ppmw Cr, 0.004 ppmw Al, 0.0001 ppmw Na, 0.000 06 ppmw Mg, 0.01 ppmw Si. The solid sample is directly analysed by flameless atomic absorption and the method is shown to give results precise to about 10%. Aqueous standards are used throughout and area measurements are found to be considerably better than peak-height calibration curves for this material. The data collection, calculation and display use a shared computer system developed at these laboratories.

Observation of surface plasmons in solid and liquid mercury

Surface plasmons were observed with energies of 6.35 \ifmmode\pm\else\textpm\fi{} 0.1 eV in solid and 6.5 \ifmmode\pm\else\textpm\fi{} 0.1 eV in liquid Hg. The energies were determined by means of reflection electron energy-loss spectroscopy using a cylindrical mirror analyzer with coaxial electron gun. The solid Hg plasmon was dispersion free within experimental error, while the plasmon in the liquid showed small positive dispersion. Proof that surface plasmons were seen was obtained by observing the shift in energy when the surface was covered with dielectric layers (${\mathrm{H}}_{2}$O for the solid, and cetyl alcohol for the liquid). The observed shifts agree well with simple calculations.

Core and valence orbitals in solid and gaseous mercury by means of ESCA

Abstract The electronic structure of Hg has been studied by means of high resolution ESCA, using monochromatized AlKα excitation. The atomic spectrum from the gas phase is compared with the solid state spectrum from frozen Hg. Electron binding energies and natural linewidths of the levels in the N, O and P shells are reported and compared with data from recent calculations. The calculations were found systematically to overestimate the linewidths when Coster-Kronig and super Coster-Kronig transitions are involved. The concept “phase transition shift” is defined and the observed phase transition shift upon sublimation of Hg is discussed. A possible relation between the cohesive energy and the difference in core and valence level phase transition shift is pointed out. The 4 f inelastic and shake-up spectrum from atomic Hg is analyzed and compared with the corresponding spectrum from solid Hg. The formation—upon sublimation—of the broad, free electron-like sp -valence band from the atomic 6 s level is demonstrated in the electron spectra. A theoretical density of states spectrum is obtained from a relativistic band structure calculation, assuming spherical symmetry. The prominent features in the theoretical spectrum were found to agree well with those of the electron spectrum.