Synthesis,Crystal Structure,Spectroscopic Characterization,Thermal Stability and Magnetic Properties of a Dinuclear Copper(Ⅱ) Complex

A new copper（Ⅱ） complex [Cu2（MNA）2（2,2‘-bipy）2]·2.5H2 O with methy-5-norbornene-2,3-dicarboxylic acid（MNA） and 2,2’-bipyridine as ligands has been synthesized in the mixed solvents of DMF and water.It crystallizes in monoclinic,space group P 1,with a = 10.4191（11）,b = 12.8883（13）,c = 16.1114（16） A,α = 70.8090（10）,β = 80.568（2）,γ = 77.440（2）o,V = 1984.3（4） A^3,Dc = 1.551 g/cm^3,Z = 2,F（000） = 962,the final GOOF = 1.051,R = 0.0431 and w R= 0.0980.The crystal structure shows that the whole molecule consists of two independent dinuclear units,in which two copper ions are bridged by two μ2-η^1：η^0 3-carboxylate groups of MNA^2-.The coordination environment of Cu（Ⅱ） ion is Cu O3N2,giving a distorted square pyramidal geometry.The spectroscopic characterization,thermal stability and magnetic properties of the complex were investigated.

A DIACETYLENE CONTAINING α-NITRONYL NITROXIDE——SYNTHESIS,CRYSTAL STRUCTURE AND MAGNETIC CHARACTERIZATION

The mono-α-nitronyl nitroxide substituted diacetylene was synthesized and its structure was established by EA,FAB-MS,IR,ESR and x-ray diffraction analysis.Using the Extracting Sample Magnetometer,its magnetic properties was investigated,and the results indicate that this compound possesses antiferromagnetic properties.

Fabrication and Characterization of Fe-Doped In2O3 Dilute Magnetic Semiconducting Nanowires

Fe-doped In2O3 dilute magnetic semiconducting nanowires are fabricated on A u-deposited Si substrates by the chemical vapor deposition technique. It is confirmed by energy dispersive x-ray spectroscopy （EDS）, x-ray photoelectron spectroscopy （XPS） and Raman spectroscopy that Fe has been successfully doped into lattices of In2O3 nanowires. The EDS measurements reveal a large amount of oxygen vacancies existing in the Fe-doped In2O3 nanowires. The Fe dopant exists as a mixture of Fe2＋ and Fe3＋, as revealed by the XPS. The origin of room-temperature ferromagnetism in Fe-doped In2O3 nanowires is explained by the bound magnetic polaron model.

Magnetic Properties in Mononuclear Gadolinium(Ⅲ) and Terbium(Ⅲ) Complexes Based on Ethoxylphenylsubstituted Nitronyl Nitroxide Radical and Hexafluoroacetylacetonate Ligand

Two new lanthanide complexes with ethoxybenzene-substituted nitronyl nitroxide radical（NIT-C_8H_9O） and hexafluoroacetylacetonate（hfac） ligand,[Gd（NIT-C_8H_9O）_2（hfac）_3]·C_7H_（16）（1） and [Tb（NIT-C_8H_9O）_2（hfac）_3]·C_7H_（16）（2）,have been successfully synthesized and characterized by IR spectroscopy,elemental analyses,thermogravimetry analyses,and single-crystal X-ray diffraction.Both 1 and 2 exhibit a mononuclear structure in which the nitronyl nitroxide radical and hfac ligand act as monodentate and bidentate chelating modes,respectively.Magnetic studies show that ferromagnetic interactions（between intramolecular Gd and radical） and antiferromagnetic interactions（between the intramolecular radicals） coexist in complex 1.No obvious frequency dependent out-of-phase signals were observed in complex 2.

Cost-effective integrated strategy for the fabrication of hard-magnet barium hexaferrite powders from low-grade barite ore

Ultrafine barium hexaferrite（BaFe12O19） powders were synthesized from the metallurgical extracts of low-grade Egyptian barite ore via a co-precipitation route. Hydrometallurgical treatment of barite ore was systematically studied to achieve the maximum dissolution efficiency of Fe（～99.7%） under the optimum conditions. The hexaferrite precursors were obtained by the co-precipitation of BaS produced by the reduction of barite ore with carbon at 1273 K and then dissolved in diluted HCl and FeCl3 solution at pH 10 using NaOH as a base; the product was then annealed at 1273 K in an open atmosphere. The effect of Fe^3＋/Ba^2＋ molar ratio and the addition of hydrogen peroxide（H2O2） on the phase structure, crystallite size, morphology, and magnetic properties were investigated by X-ray diffraction, scanning electron microscopy, and vibrating sample magnetometry. Single-phase BaFe（12）O（19） powder was obtained at an Fe^3＋/Ba^2＋ molar ratio of 8.00. The formed powders exhibited a hexagonal platelet-like structure. Good maximum magnetization（48.3 A×m^2×kg^–1） was achieved in the material prepared at an Fe^3＋/Ba^2＋ molar ratio of 8.0 in the presence of 5% H2O2 as an oxidizer and at 1273 K because of the formation of a uniform, hexagonal-shaped structure.

APPLICATION OF MAGNETIZATION VISCOUS CHARACTER OF MAGNETIC FLUID IN ELECTRO-HYDRAULIC SERVO AMPLIFIER

The magnetic fluid is used as working medium in pilot stage of electro-hydraulic servoamplifier. Utilizing the magnetization viscous character of the fluid, a new type of electro-hydraulicservo amplifier without any moving parts in its pilot stage has been developed. This research provides a way for improving the frequency property and reliability of electro-hydraulic servoelements.