Carbometallic derivatives of hydroborons C2h and D5d: A list of substitution isomers

The problem of determining the number and type of X-substituted (where X represents certain substituents) carbometallic derivatives of hydroborons [Co(C₂B₉H₁₁)₂]⁻ C _2h and [Co(C₅B₆H₁₁)₂]⁻ D _5d (from apexes) was solved on the basis of G. Pólya’s theorem by means of combinatory analysis. The formulae of symmetry Z and generating functions of the number of achiral substitution isomers were determined. The family distributions of isomers (depending on the type and number of substituents) and the sites of possible substitution depending on the number m were determined. Mono and di-X-substituted isomers of [Co(C₅B₆H₁₁)₂]⁻ C _2h , as well as mono and di-X-substituted isomers of [Co(C₅B₆H₁₁)₂]⁻ D _5d , were identified. The procedure for plotting an additive model of calculating the properties of isomers of apical substitution of [Co(C₅B₆H₁₁)₂]⁻ D _5d was described on the basis of splitting of polygonal numbers (K ₃, K _TE, K ₅, and so on) of Pascal triangle, upon use of which there is no randomization in the choice of parameters of calculation model. The additive schemes containing 7 and 25 parameters for the calculation of properties of X-substituted carbometallic derivative of hydroboron [Co(C₅B₆H₁₁)₂]⁻ D _5d to various approximations were obtained.     

LixNi0.5Co0.5O2的态密度计算及电化学性能研究

>为获得综合性能更好的锂离子二次电池正极材料, 分析了Co掺杂对Li_xNiO₂电化学性能的影响. 采用密度泛函DFT理论对Li_xNiO₂和Li_xNi_0.5Co_0.5O₂的平均放电电压和态密度进行了计算. 同时, 用共沉淀法制备了Li_xNiO₂和Li_xNi_0.5Co_0.5O₂锂离子二次电池正极材料, 并对其进行了XRD结构分析和恒流充放电测试. 实验和计算结果表明: 随锂离子嵌入正极(电池放电), 电池的电压逐渐降低, 材料的态密度峰向低能量方向移动; 与Li_xNiO₂相比, Li_xNi_0.5Co_0.5O₂的电压平台相对较高(当0.25≤x≤0.5), 而且在Li^＋嵌/脱时, Li_xNi_0.5Co_0.5O₂的结构变化相对较小; Co离子的掺入, 减小了NiO₆八面体的畸变度, 使材料的电化学稳定性得以提高. 在钴掺杂镍酸锂体系中, NiO₆和CoO₆具有相互的稳定作用.     

Röntgenographische Bestimmung der thermischen Störung in den Kristalliten partiell kristallisierter Polyäthylene

Summary The dielectricα _a - andβ _a -absorptions in the linear high polymers whose dipoles are short and rigidly attached to their main chains are investigated theoretically and compared with our observed data. Suffix “a” represents that dielectric absorption comes from amorphous part. Examples of this kind are polyvinyl chloride, polyvinyl bromide, polyethylene isophthalate, polyethylene terephthalate and polyoxymethylene. Theα _a -absorptions are attributed to the re-orientations of their dipoles due to the segmental micro-Brownian motions of the polymer chains in the amorphous part. Theβ _a -absorptions seem to be caused by local micro-Brownian motions of the polymer chains. Theβ _a -absorptions are described by a model of local viscoelastic relaxations of the “dipoles” in the vicinity of their equilibrium directions. Here, the term “dipole” represents the resultant dipole of the permanent dipoles in the motional unit which has about the same order of magnitude as the monomer unit. Thus the various properties ofα _a - andβ _a -absorptions are calculated and agree with our observed values at least semi-quantitatively. In the second section the equations ofα _a - andβ _a -absorptions are derived. The properties of theα _a -absorptions are calculated in the third section and compared with our observed data. The magnitudes ofα _a -absorptions of the semi-crystalline polymers are smaller than those of the amorphous polymers even in the amorphous samples of the semi-crystalline-polymers. The temperature dependence of the magnitude ofα _a -absorption is far gentler in the crystalline polymer compared with the amorphous at temperatures higher than glass transition temperature (T _g ). These observed tendencies are explained by our theory. The calculated values of the activation energies ofα _a -absorptions are 50 ≈ 150 kcal/mol, the same orders as the observed values. The shape of theα _a -absorption is given by the form [ε(iω) -ε∞]/[ε ₀-g3 _∞] = [(1+iω π ₁ (1 +iωπ ₂)^−1/2 at temperatures higher thanT _g . This is in good agreement with the observed shape in the amorphous polymer, not only for the order of breadth but also for the order of asymmetry. The shape of theα _a -absorption in the semi-crystalline polymer is given by a superposition of the above formula and leads to the same order of breadth as the observed shape, too. The properties ofβ _a absorptions are calculated in the fourth section with the aid of the above mentioned model. The calculated values of the magnitudeβ _a -absorptions show fairly good agreement with the observed values too. The temperature dependence of the magnitude ofβ _a -absorption is discussed. The calculated values of the activation energies of theβ _a -absorptions are of the order 10 ≈ 20 kcal/mol, in good agreement with the observed values. The shape ofβ _a -absorption is also given by a superposition of the above formula and leads to the same order of breadth as the observed shape. The order of asymmetry of our theoretical absorption curve agrees with that of the observed curve.

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Vorgetragen auf der Sitzung des Fachausschusses Physik der Hochpolymeren im Verband der Deutschen Physik. Gesellschaft auf der Physikertagung in Wien, 21. Okt. 1961.

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Mit 11 Abbildungen und 3 Tabellen     

Determination of the enthalpy of fusion of K3TaF8 and K3TaOF6

The areas of the fusion and crystallization peaks of K₃TaF₈ and K₃TaOF₆ have been measured using the DSC mode of the high-temperature calorimeter (SETARAM 1800 K). On the basis of these quantities and the temperature dependence of the used calorimetric method sensitivity, the values of the enthalpy of fusion of K₃TaF₈ at temperature of fusion 1039 K: Δ_fusH_m(K₃TaF₈; 1039 K) = (52 ± 2) kJ mol⁻¹ and of K₃TaOF₆ at temperature of fusion 1055 K: Δ_fusH_m(K₃TaOF₆; 1055 K) = (62 ± 3) kJ mol⁻¹ have been determined.     

Determination of cyanide in blood by electrospray ionization tandem mass spectrometry after direct injection of dicyanogold

An electrospray ionization tandem mass spectrometric (ESI-MS-MS) method has been developed for the determination of cyanide (CN^–) in blood. Five microliters of blood was hemolyzed with 50 μL of water, then 5 μL of 1 M tetramethylammonium hydroxide solution was added to raise the pH of the hemolysate and to liberate CN^– from methemoglobin. CN^– was then reacted with NaAuCl₄ to produce dicyanogold, Au(CN)₂^–, that was extracted with 75 μL of methyl isobutyl ketone. Ten microliters of the extract was injected directly into an ESI-MS-MS instrument and quantification of CN^– was performed by selected reaction monitoring of the product ion CN^– at m/z 26, derived from the precursor ion Au(CN)₂^– at m/z 249. CN^– could be measured in the quantification range of 2.60 to 260 μg/L with the limit of detection at 0.56 μg/L in blood. This method was applied to the analysis of clinical samples and the concentrations of CN^– in the blood were as follows: 7.13 ± 2.41 μg/L for six healthy non-smokers, 3.08 ± 1.12 μg/L for six CO gas victims, 730 ± 867 μg for 21 house fire victims, and 3,030 ± 97 μg/L for a victim who ingested NaCN. The increase of CN^– in the blood of a victim who ingested NaN₃ was confirmed using MS-MS for the first time, and the concentrations of CN^– in the blood, gastric content and urine were 78.5 ± 5.5, 11.8 ± 0.5, and 11.4 ± 0.8 μg/L, respectively.     

Thermal behavior and thermal safety on 3,3-dinitroazetidinium salt of perchloric acid

3,3-Dinitroazetidinium (DNAZ) salt of perchloric acid (DNAZ·HClO₄) was prepared, it was characterized by the elemental analysis, IR, NMR, and a X-ray diffractometer. The thermal behavior and decomposition reaction kinetics of DNAZ·HClO₄ were investigated under a non-isothermal condition by DSC and TG/DTG techniques. The results show that the thermal decomposition process of DNAZ·HClO₄ has two mass loss stages. The kinetic model function in differential form, the value of apparent activation energy (E _a) and pre-exponential factor (A) of the exothermic decomposition reaction of DNAZ·HClO₄ are f(α) = (1 − α)⁻¹/2, 156.47 kJ mol⁻¹, and 10^15.12 s⁻¹, respectively. The critical temperature of thermal explosion is 188.5 °C. The values of ΔS ^≠, ΔH ^≠, and ΔG ^≠of this reaction are 42.26 J mol⁻¹ K⁻¹, 154.44 kJ mol⁻¹, and 135.42 kJ mol⁻¹, respectively. The specific heat capacity of DNAZ·HClO₄ was determined with a continuous C _p mode of microcalorimeter. Using the relationship between C _p and T and the thermal decomposition parameters, the time of the thermal decomposition from initiation to thermal explosion (adiabatic time-to-explosion) was evaluated as 14.2 s.     

Relationships on the effect of water on glass transition temperature and young's modulus of nylon 6

The glass transition temperature T_g of nylon 6 decreases monotonically toward a finite value T_gl upon increase of the moisture content. The mechanism of this decrease entails the reversible replacement of intercaternary hydrogen bonds in the accessible regions of the polyamide. The limiting glass transition temperature T_gl is approached when the moisture content approaches W_l, which corresponds to the amount of water required for complete interaction with all accessible amide groups. Denoting with T_g0 the glass transition temperature of the dry polymer, the effect of water on T_g is represented by the equation, T_g = (ΔT_g)₀ exp{?[ln(ΔT_g)₀]W/_τW_l} + T_gl, where (ΔT_g)₀ = T_g0 ?T_gl, and τ = W(T_gl+1)/W_l. This equation appears to be generally applicable to hydrophilic polymers, since correspondingly calculated data are also in very good agreement with experimental data for polymers such as nylon 66, poly(vinyl alcohol), and polyN-vinylpyrrolidone. The effect of water of Young's modulus E of nylon 6 is represented by an analogous relationship, and the quantity In[(E?E_l)/(T_g?T_gl)] is a linear function of the moisture content.     

Polyatomic anion versus acetonitrile in coordinating ability: structural properties of AgX-bearing 1,4-bis(2-isonicotinoyloxyethyl)piperazine (X??=?NO3?, CF3SO3?, ClO4?, BF4?, and PF6?)

Type studies on competitive polyatomic anion versus acetonitrile coordination in the self-assembly of a series of [Ag₂(X) _m (bip)(NCCH₃) _n ](X)_2−m (X⁻ = NO₃ ⁻, CF₃SO₃ ⁻, ClO₄ ⁻, BF₄ ⁻, and PF₆ ⁻; m = 0, 2; n = 0, 2, 4; bip = 1,4-bis(2-isonicotinoyloxyethyl)piperazine) were carried out. Each bip spacer acts as an N₄ tetradentate ligand and is linked to four silver(I) centers through two pyridine and two piperazine moieties, producing a double strand consisting of two 20-membered ring units. The coordinating environment around the silver(I) center is subtly determined by the competition of the polyatomic anions with acetonitrile, that is, by the Ag···NCCH₃ versus Ag···X interactions. The coordinating ability of acetonitrile is inversely proportional to the order of the coordination ability of the Hoffmeister series of polyatomic anions, NO₃ ⁻ ≫ CF₃SO₃ ⁻ > ClO₄ ⁻ > BF₄ ⁻ ≫ PF₆ ⁻.     

Thermodynamic properties of complex oxides in the La-Ni-O system

Complex oxides La₂NiO_4+δ, La₃Ni₂O_7−δ, La₄Ni₃O_10−δ and LaNiO_3−δ, the members of Ruddlesden-Popper series La_n+1Ni_nO_3n+1, were prepared using citrate precursors. The stability range of LaNiO_3−δ in air as well as the oxygen nonstoichiometry of La₃Ni₂O_7−δ and La₄Ni₃O_10−δ as a function of temperature and oxygen partial pressure was determined by means of thermogravimetric technique. Decomposition temperatures of La₃Ni₂O_7−δ, La₄Ni₃O_10−δ and LaNiO_3−δ in air were determined by conductivity measurement method. The boundary of stability for La₄Ni₃O_10−δ was determined by EMF measurements of galvanic cell with oxygen conducting solid electrolyte. The isothermal (1400 K) projection of La-Ni-O system phase diagram to the plane “log(PO₂)-relative mole fraction of metal components” was suggested.     

A new equation for the size distribution of emulsion particles

Summary A study of experimental data from the literature provided grounds for believing that the particle size distributions of emulsions can be represented by a single general size distribution equation. In the present paper this distribution equation, which contains two parameters, is derived statistically. Verification with published experimental data on several oil-in-water emulsions and with own data on water-in-oil emulsions yielded very good agreement for mechanically prepared emulsions.

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Zusammenfassung Ein Studium der experimentellen Ergebnisse aus dem Schrifttum legt nahe, daß die Teilchengrößenverteilungen von Emulsionen durch eine einzige generelle Verteilungsgleichung dargestellt werden können. Die vorliegende Arbeit gibt eine statistische Ableitung dieser Verteilungsfunktion, die zwei Parameter enthält. Die PrÜfung mit veröffentlichten experimentellen Ergebnissen an verschiedenen öl-in Wasser-Emulsionen und mit eigenen Experimenten an Wasser- in öl-Emulsionen ergab fÜr mechanisch präparierte Emulsionen sehr gute Übereinstimmungen.

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List of symbols A constant - a parameter of the equation; characteristic diameter - constant - constant - D sum of the diameters of all globules - dd sum of the diameters of the globules in the diameter interval fromx tox +dx - m number of categories - N total number of globules - n _i number of globules ini-th category - dn number of globules in the diameter interval fromx tox +dx. - _i number of volume elements in thei-th category - P probability - p number of volume elements in volumeV - S total surface area of the globules - s surface area of a globule - s _i surface area of a globule in thei-th category - ds surface area of the globules in the diameter interval fromx tox +dx - V total volume of the globules - v volume of a globule - v _i volume of a globule in thei-th category - v _x cumulative volume below sizex - dv volume of the globules in the diameter interval fromx tox +dx - w specific surface area of a globule - w _i specific surface area of a globule in thei-th category - X parameter of the equation; largest globule occurring - x variable globule diameter - X _i diameter of a globule in thei-th category.     

Interaction between two double layers for Na3PO4 types electrolytes at y0 > yd > 0

Interaction between two double layers for the Na₃PO₄ type electrolytes at y ₀ > y _d > 0 were investigated with the aid of λ parameter methods and the accurate numeral results were given. The maximum of the interaction energies between two double layers for A_v+ B_v- A_{v_ + } B_{v_ - } type electrolytes at y ₀ > y _d > 0 is independent of y ₀, but increases with y _d . The interaction energies between two double layers for NaCl, CaCl₂, FeCl₃, Na₂SO₄ and Na₃PO₄ type electrolytes at y ₀ = 5 and y _d = 2 were compared. If the negative or positive ions for A_v+ B_v- A_{v_ + } B_{v_ - } type electrolytes have the same charge number, the maximum of their interaction energies increases with the charge number of the ions of opposite charge. If the negative or positive ions of the electrolytes have different charge numbers, the relative heights of the maxima of their interaction energies are indefinite. For the in pairs conjugate type electrolytes like CaCl₂ and Na₂SO₄ or FeCl₃ and Na₃PO₄, the larger the charge number of the negative ions of the electrolytes is, the higher the maximum of their interaction energies is. The results for Na₃PO₄ type electrolytes at y ₀ > y _d > 0 can also be applied to FeCl₃ type electrolytes at y ₀ > y _d > 0.     

The effect of high pressure on the ion pair equilibrium constant of alkali metal fluorides: A spectrophotometric study

Bromophenol blue indicator was used in UV-visible spectrophotometric measurements to study ion association constants of alkali metal fluorides. The equilibrium constants for the ion pair formation of the alkali metal fluorides were determined as a function of ionic strength at one atmosphere pressure and 25°C. The effect of pressure on these association constants was measured at a constant total ionic strength of 1.0 mol-kg^–1 over a pressure range of 1 to 2000 atmospheres at 25°C. The pressure dependences of the stoichiometric association constants of the alkali metal fluorides are given by: lnK _LiF ^* =0.77–2.47×10^–4P–2.12×10^–8P²; lnK _NaF ^* =0.53–1.08×10^–4P–1.66×10^–8P²; lnK _KF ^* =0.24–4.41×10^–5P–7.15×10^–8P²; lnK _RbF ^* =–0.17–8.65×10^–5P–4.51×10^–8P²; and lnK _CsF ^* = –0.37–1.14×10^–4P–6.82×10^–8P², where P is the pressure in atmospheres. The stoichiometric molar volume and compressibility changes for ion pair formation of the alkali metal fluorides were evaluated from the pressure dependence of K _MF ^* data. The thermodynamic association constants were also calculated making use of activity coefficient data from the Pitzer equations. The partial molal volume and compressibility changes for ion pair formation of each alkali metal fluoride are reported.     

A novel bimediator amperometric sensor for electrocatalytic oxidation of gallic acid and reduction of hydrogen peroxide

A novel bimediator amperometric sensor is fabricated for the first time by surface modification of graphite electrode with thionine (TH) and nickel hexacyanoferrate (NiHCF). The electrochemical behavior of the TH/NiHCF bimediator modified electrode was characterized by cyclic voltammetry, differential pulse voltammetry and chronoamperometry. The TH/NiHCF bimediator modified electrode exhibited a pair of distinct redox peaks for NiHCF and TH with formal potentials of 0.33 V and −0.27 V vs. SCE at a scan rate of 50 mV s⁻¹ in 0.1 M NaNO₃ and 0.1 M NH₄NO₃ respectively. The electrocatalytic activity of the bimediator modified electrode towards oxidation of gallic acid with NiHCF and reduction of hydrogen peroxide with TH was evaluated and it was observed that the modified electrode showed an electrocatalytic activity towards the oxidation of gallic acid in the concentration range of 4.99 × 10⁻⁶–1.20 × 10⁻³ M with a detection limit of 1.66 × 10⁻⁶ M (S/N = 3) and reduction of H₂O₂ in the concentration range of 1.67 × 10⁻⁶–1.11 × 10⁻³ M with a detection limit of 5.57 × 10⁻⁷ M (S/N = 3). The bimediator modified electrode was found to exhibit good stability and reproducibility.     

Synthesis and properties of LiMIIPO4 (MII = Mg,Mn0.5Mg0.5, Co0.5Mg0.5) affected by isodivalent doping and Li-sources

NH₄M^IIPO₄·H₂O (M^II = Mg, Mn_0.5Mg_0.5, Co_0.5Mg_0.5) were synthesized by direct-precipitating method. The olivine-like LiM^IIPO₄ were successfully generated through the solid state reaction between the synthesized NH₄M^IIPO₄·H₂O precursors and two different Li-sources (Li₂CO₃ or LiOH·H₂O). The NH₄M^IIPO₄·H₂O and LiM^IIPO₄ compounds were confirmed by TG/DTG/DTA, AAS/AES, FTIR and XRD methods. The structural and morphological properties of LiM^IIPO₄ compounds were studied by XRD and SEM, respectively. The XRD reflection shifts of olivine-like LiM^IIPO₄ from the Li-source of Li₂CO₃ revealed changing toward higher diffraction angles than that of LiM^IIPO₄ from the Li-source of LiOH·H₂O. The XRD shifts of LiM_0.5Mg_0.5PO₄ (M = Mn or Co) compounds confirmed the formation of the single phase of isodivalent doping of Mn²⁺ and Co²⁺ ions according to the change in the lattice parameters and cell volumes. The morphological investigations of the LiM^IIPO₄ obtained from Li₂CO₃ system illustrated the grain-like shape particles having smaller size of about 150–400 nm on account of the sequential transformations of types: deammoniation, dehydration, polycondensation and decarbonization. Conversely, the larger size particles (300–700 nm) of the LiM^IIPO₄ obtained from LiOH·H₂O were observed due to the shorter transformation path through the reactions of types: deammoniation and dehydration without polycondensation and decarbonization.     

Thermochemistry of the solid complex Gd(Et<Subscript>2</Subscript>dtc)<Subscript>3</Subscript>(phen)

Summary A ternary solid complex Gd(Et₂dtc)₃(phen) has been obtained from reactions of sodium diethyldithiocarbamate (NaEt₂dtc), 1,10-phenanthroline (phen) and hydrated gadolinium chloride in absolute ethanol. The title complex was described by chemical and elemental analyses, TG-DTG and IR spectrum. The enthalpy change of liquid-phase reaction of formation of the complex, Δ_rH^Θ_m(l), was determined as (-11.628±0.0204) kJ mol^-1 at 298.15 K by a RD-496 III heat conduction microcalorimeter. The enthalpy change of the solid-phase reaction of formation of the complex, Δ_rH^Θ_m(s), was calculated as (145.306±0.519) kJ mol^-1 on the basis of a designed thermochemical cycle. The thermodynamics of reaction of formation of the complex was investigated by changing the temperature of liquid-phase reaction. Fundamental parameters, the apparent reaction rate constant (k), the apparent activation energy (E), the pre-exponential constant (A), the reaction order (n), the activation enthalpy (Δ_rH^Θ_≠), the activation entropy (Δ_rS^Θ_≠), the activation free energy (Δ_rG^Θ_≠) and the enthalpy (Δ_rH^Θ_≠), were obtained by combination of the thermodynamic and kinetic equations for the reaction with the data of thermokinetic experiments. The constant-volume combustion energy of the complex, Δ_cU, was determined as (-18673.71±8.15) kJ mol^-1 by a RBC-II rotating-bomb calorimeter at 298.15 K. Its standard enthalpy of combustion, Δ_cH^Θ_m, and standard enthalpy of formation, Δ_fH^Θ_m, were calculated to be (-18692.92±8.15) kJ mol^-1 and (-51.28±9.17) kJ mol^-1, respectively.     

Volumetric properties of aqueous solutions of quinic acid and its sodium salt

Abstract  

The apparent molar volume of quinic acid and its sodium salt were determined from the density data of aqueous solutions up to molality of 0.4 mol kg⁻¹ and in the temperature range from 293.15 to 328.15 K. The apparent molar volume of sodium quinate comprises the ionic and the associated ion-pair contributions. From the apparent molar volumes of quinic acid and the quinate ion, the molecular contributions to that of quinic acid are derived. At 298.15 K, the limiting apparent molar volume of quinic acid is 119.8 ± 0.5 cm³ mol⁻¹, and that of the quinic ion is 111.6 ± 0.3 cm³ mol⁻¹. Similarly, at 298.15 K, the limiting apparent molar expansibility of sodium quinate is 0.198 ± 0.003 cm³ mol⁻¹ K⁻¹, and that of quinic acid is 0.142 ± 0.003 cm³ mol⁻¹ K⁻¹. From these limiting ionic and molecular apparent molar volumes, the limiting volume change caused by ionization of quinic acid was calculated as −8.2 cm³ mol⁻¹ at 298.15 K. The coefficients of thermal expansion of these solutions were calculated from the density data, and from these the apparent molar expansibilities of quinic acid and its sodium salt were derived.     

Effect of boron non-stoichiometry on B-site in perovskite type structure ScBxRh3 and CeBxRh3 on charges of atoms on A-site: study by X-ray photoelectron and nuclear magnetic resonance spectroscopies

The solid solutions of ScBRh₃-ScRh₃ and CeBRh₃-CeRh₃ are synthesized by the arc melting method, where RBRh₃ and RRh₃ (R=rare earth element) have perovskite and AuCu₃ type structures, respectively. The binding energy of Sc 2p_3/2 for ScB_xRh₃ increases with the boron concentration. The Knight shift of ⁴⁵Sc observed by nuclear magnetic resonance spectroscopy decreases with increase of boron concentration. The decrement of the Knight shift corresponds the Sc 4s electron density at the Fermi level. The intensity ratio of f²: f¹: f⁰ of Ce 3d XPS spectrum changes with boron concentration of CeB_xRh₃. It is concluded that in both cases of ScB_xRh₃ and CeB_xRh₃ the charge on the atoms on A-site changes with the concentration of the atoms on B-site, where the atoms are not directly bound.     

Diffusion of point defects participating in solid-phase chemical reactions (trap diffusion): Demonstration for the Ti3+ → Ti4+ transition in corundum

A problem of trap diffusion, that is diffusion of point defects in crystals participating in a solid-phase chemical reaction with motionless impurity ions, is solved. Time dependences of the reaction-front displacement, X_f, and its steepness, $\text{(}\text{?C}\text{?X}\text{)}{}_{\mathrm{f}}$ are determined analytically for N₀ ? C₀ and numerically for all relations of N₀ and C₀$\text{x}{}_{\mathrm{f}}{}^2\text{=2}\text{N}{}_0\text{C}{}_0\text{Dt; (}\text{ac}\text{ax}\text{)}{}_{\mathrm{f}}\text{=0.3C}{}_0{}^{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}\text{(}\text{g}\text{D}\text{)}{}^{\mathrm{<mtext>1</mtext><mtext>2></mtext>}}$where C₀ and N₀ are the initial concentration of impurity and the eqilibrium defect concentration, respectively, D is a diffusion coefficient, and g is a chemical reaction constant. Dependence of X_f vs C₀ and t is confirmed for oxygen annealing of corundum crystals doped with titanium which, reacting with the point defects, changes its valency. The data are obtained for dependence of displacement X_f upon partial oxygen pressure and thermotreatment temperature as well as upon the sign of the constant electric field applied to the sample. From these data we conclude that the reaction of titanium impurity, changing from the three-valent to the tetravalent state at the activation energy of 80 ± 8.5 kcal/mole is due to anisotropic diffusion of charged aluminum vacancy and holes in the valence band. The diffusion coefficient for that process at 1500°C is estimated to be larger than 10^?5 cm²/sec. Using the trap-diffusion features, the concentration of optical centers of the 0.315-μm absorption band in ruby is also estimated.     

New organosols of nickel sulfides,palladium sulfides,manganese sulfide,and mixed metal sulfides and their use in preparation of semiconducting polymer-metal sulfide composites

Organosols of NiS, PdS, and MnS in N,N-dimethylformamide were prepared by reaction of the metal acetate with H₂S. Organosols of mixed-metal sulfides (Zn _x Cd_1–x S, Hg _x Cd_1–x S, Hg _x Cu_1–x S, Cd _x Mn_1–x S, Hg _x Mn_1–x S, Hg _x Cd_1–x S, and Mn _x Zn_1–x S) were similarly obtained by reaction of mixtures of the metal salts with H₂S. The organosol of Zn_0.5Cd_0.5S contained particle with two particle size distributions centered at 6.5 nm and 29 nm, as revealed by Ar laser-scattering analysis. The metal sulfides are recovered by addition of Et₂O to the organosols. Zn _x Cd_1–x S thus obtained shows magnetic susceptibility in the range 0.5×10^–6–2.3×10^–6 emug^–1 depending on thex value. Addition of polymers to the organosols affords semiconducting films of metal sulfide-polymer composites.