A Spin‐Active,Electrochromic, Solvent‐Free Molecular Liquid Based on Double‐Decker Lutetium Phthalocyanine Bearing Long Branched Alkyl Chains

Synthesis and characterization of a novel, multifunctional, solvent‐free room‐temperature liquid based on alkylated double‐decker lutetium(III) phthalocyanine (Pc₂Lu) are described. Lowering of the melting point and viscosity of intrinsically solid Pc₂Lu compounds has been achieved through the attachment of flexible, bulky, and long branched‐alkyl chains, that is, thio‐2‐octyldodecyl, to the periphery of the Pc₂Lu unit. The embedded Pc₂Lu unit maintains its inherent molecular functions, such as spin‐active nature and electrochromic behavior in the liquid state. Comparison of the properties with a solid‐like Pc₂Lu derivative, functionalized with shorter alkyl chains, that is, thio‐2‐ethylhexyl, underlines the importance of the hampering effect on the π–π interactions of neighboring Pc₂Lu molecules by bulkier and longer branched‐alkyl chains. This study could possibly pave the way for novel multifunctional liquids whose spin‐activities are associated with their rheological or optoelectronic properties.     

Effect of processing parameters on the structure and magnetic properties of Nd60Fe30Al10 alloy

Although rapidly solidified Nd–Fe–Al alloys exhibit hard magnetic properties they so far have not found any practical application, however, their study has great scientific meaning. Investigations of the Nd–Fe–Al alloys enable one to evaluate the effect of magnetic interactions, between nanoscale precipitates, having different structure and properties, on the macroscopically observed phenomena. The evolution of microstructure in the course of annealing is generally unclear. Most of the reported data were obtained for different materials, using various processing methods, which makes their comparison difficult. It was shown that different fabrication methods (melt spinning, suction casting) generate different properties. On the other hand, for the particular processing method the structure and magnetic properties are highly affected by the processing variables.

In this study the samples fabricated by two methods were compared. Melt spinning, with the roll speed 5–30 m/s, and casting into moulds having bore diameters 1, 3, 6 and 12 mm were used. The alloy composition was kept constant Nd₆₀Fe₃₀Al₁₀. Strong dependence of the magnetic properties on quenching rate was proved. Application of the appropriate processing variables for both the methods (roll speed or rode diameter) enables one to obtain comparable quenching rates and thus overall similar magnetic properties. However, for the cylindrical specimens different cooling rates for the surface and core produces a structural gradient, which leads to variation of the magnetic properties on the sample cross-section. The structural and property gradients were evaluated using SEM and magnetic measurements, respectively.     

Magnetic properties of polymer matrix nanocomposites on a basis of metal carboxylates

Metallopolymer nanocomposites on the bases of cobalt and iron acrylates as well as their cocrystallites have been obtained and characterized. Microstructure of the materials consists of both agglomerated and individual nanocrystallites which are homogeneously distributed in the polymer matrix. Mean crystallite size is 7-14 nm. All the composite materials exhibit soft magnetic properties at room temperature. The magnetic parameters are controlled by the intrinsic magnetic properties of the constituents and agglomeration of the particles.