Anisotropy of Magnetoelectric Properties of Ferrite–Piezoelectric Bulk Composites

Technical Physics - The anisotropy of magnetoelectric properties of lead zirconate–titanate and nickel ferrite based bulk composites has been experimentally studied. It has been shown that a...     

Magnetic and electric properties of Yb x Mn1 − x S alloys

Results from investigating the structural, magnetic, and electrical properties of Yb _x Mn_{1 ? x} S alloys (0 ≤ x ≤ 0.2) synthesized on the basis of manganese monosulfide are presented. Substituting manganese for ytterbium increases the concentration of charge carriers and lowers the activation energy. The observed anomalies in the temperature dependence of resistivity are explained by an impurity semiconductor model with donor 4f levels.     

Structural, magnetic, and electrical properties of solid solutions of the chromium telluride-manganese telluride system

The conditions for synthesis of solid solutions in the quasibinary CrTe-MnTe system are analyzed. A study is made of the effect of cation substitution on the properties of the synthesized solid solutions in measurements of magnetization, magnetic susceptibility, electrical conductivity, and the Seebeck coefficient at temperatures of 80–750 K. Fiz. Tverd. Tela (St. Petersburg) 39, 320–324 (February 1997)     

Surface analysis and corrosion resistance of new nickel base thin film alloys

Electroless Zn–Ni–P thin films were deposited on low carbon steel from an alkaline non‐cyanide aqueous electrolyte. The newly developed ternary alloys structure and microstructure investigations were carried out via X‐ray diffraction and SEM. Chemical composition of the coatings was investigated via energy dispersive spectroscopy. Polarization tests were used to study the corrosion properties of the coatings in a 3.5 wt.% NaCl solution. The results confirmed the high corrosion resistance of Zn–Ni–P alloy plated steel sheet. The surface analysis of the thin film samples before and after corrosion was performed by XPS. The incorporation of Zn in Ni–P thin film is proven for all initial samples to be as a mixture of zinc and zinc oxide, while nickel exists in +2 and +3 oxidized states. A passive film of a mixture of oxide and hydroxide of zinc and nickel forms on the surface and prevents the Zn–Ni–P thin films from corrosion. Copyright © 2014 John Wiley & Sons, Ltd.     

Solid solutions in the Zn-Co-O system: Physicochemical properties

Physicochemical analysis is used to study phase equilibria and to design a concentration diagram for the Zn-Co-O system. ZnO-, CoO-, and Co₃O₄-based mixed crystals with a fixed Zn/Co ratio have different oxygen nonstoichiometry depending on the synthesis and annealing parameters. Metastable clustering is discovered in Zn_{1 ? x} Co_xO_{1 + δ} wurtzite solid solutions, which exist stably in the range 0 ≤ x ≤ 0.2. Magnetization investigation shows that an antiferromagnetic order exists in homogeneous Zn_{1 ? x} Co_xO_{1 + δ} grains; this order is conserved up to 625 ± 25 K. The substitution of praseodymium, neodymium, samarium, or europium for zinc(II) cations in Zn_0.9Co_0.1O_{1 + δ} does not spoil the compensated antiferromagnetism of the wurtzite unit cell.     

Effect of electrolyte components on the magnetic and magnetoresistive characteristics of Fe-containing plasma electrolytic oxide coatings on titanium

The effect replacing Na₃PO₄ with Na₂HPO₄ in aqueous phosphate–borate–tungstate electrolyte that additionally contains Fe₂(C₂O₄)₃ on the magnetic and magnetoresistive characteristics of oxide coating/ titanium composites formed by means of plasma electrolytic oxidation (PEO) is investigated. It is established that PEO coatings with ferromagnetic characteristics form on titanium in an electrolyte containing Na₃PO₄ (pH ~ 11) upon adding iron(III) oxalate, while replacing Na₃PO₄ with Na₂HPO₄ and the respective drop in the pH of the base electrolyte down to 9.8 results in the formation of coatings with different magnetic characteristics. The correlation between changes in the values of the charge carriers’ activation energy and the magnetic susceptibility is demonstrated for the latter. An increase in the electric resistance of coatings in a magnetic field is observed, and the type of the magnetic resistance temperature dependence is established.

     

Recovery of Metals from Anodic Dissolution Slime of Waste from Electric and Electronic Equipment(WEEE) by Extraction in Ionic Liquids

The recovery of metals from a multi-component alloy obtained by crushing, melting and anodic dissolution of waste from electric and electronic equipment(WEEE) was investigated. The anodic dissolution of the alloy was carried out in an electrolysis cell with one copper cathode and a central cast anode, immersed in the electrolyte formed by choline chloride-ethylene glycol-iodine. The temperature of the electrolyte during the process was 343 K. Depending on the electrolysis parameters(current density and cell voltage), cathodic deposits of Sn, Pb and Zn of >99% purity were obtained. Cyclic voltammetry was used in order to determine the deposition potentials of the studied metals. The obtained metallic deposits were subject of determination of XRD, SEM/EDX and AFM in order to evidence the deposits structure and morphology. The experiments performed demonstrated the possibility of separating/selective recovery of metals from the multi-component alloy resulted from the waste from electrical and electronic equipment by anodic dissolution in ionic liquids.     

Magnetic and magnetoresistive properties of Gd<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>Mn<Subscript>1–<Emphasis Type="Italic">x</Emphasis></Subscript>Se selenides

Gd _x Mn_1–x Se (0 ≤ х ≤ 0.15) solid solutions are synthesized on the basis of manganese monoselenide. Their magnetic and electrical properties are studied in the temperature range of 80–900 K in magnetic fields up to 10 kOe. An FCC lattice with the Fm3m space group and antiferromagnetic ordering of the magnetic moments of manganese ions is found. A monotonic reduction in the Néel temperature and an increase in the effective magnetic moment along with the gadolinium concentration are observed. Anomalies in the temperature dependence of electrical resistivity and a shift in the temperatures of anomalies in a magnetic field are found.     

Synthesis and Tautomeric Equilibrium of Polyfluoroacyl-Containing 1,5-Benzodiazepines

Summary. The reaction of bis(polyfluoroalkyl)-containing 1,3,5-triketones with o-phenylenediamine yielded 2-polyfluoroacylmethylene-4-polyfluoroalkyl-1,3- or 1,5-dihydro-1,5-benzodiazepines. The tautomeric equilibrium of the obtained benzodiazepines in CDCl₃, CD₃CN, DMSO, and DMF solution was studied.