Phase behaviour of the suspensions based on magnetic nanoplatelets

Patricija Hribar Boštjančič
Jožef Stefan International Postgraduate School, Department of Complex Matter, IJS

Abstract:

Alcohol suspensions of ferrimagnetic Sc-substituted barium hexaferrite (BHF) nanoplatelets present a specific kind of ferrofluids. The formation of a unique example of a dipolar fluid – a liquid magnet is induced by concentrating the nanoplatelets’ suspension. Crucial interactions between the nanoplatelets that lead to the formation of the ferromagnetic nematic phase are long-range dipolar magnetic and screened anisotropic electrostatic interactions. The latter are controlled with the surfactant dodecylbenzenesulfonic acid that forms an electrical double layer and enables colloidal stabilization of the nanoplatelets in alcohols. The nematic phase formation in the suspensions was studied as a function of the concentration of the dodecylbenzenesulfonic acid, the size distribution and the saturation magnetization of the nanoplatelets. These parameters affect the interactions between the nanoplatelets and, thus, determine the formation of the liquid magnet.

Synthesis and Decoration of Molybdenum Oxide Nanowires 

Timi Babič
student, Department of Complex Matter, IJS

Abstract:

In my work I synthesized hybrid nanowire material made out of anilin complex and molybdenum oxide. With heating in Ar atmosphere the material was transformed into MoO2 nanowires, which were then decorated with nanoparticles of noble metals (Au, Pt, Pd). For decoration noble metal coordination complexes were used. With adjusting the molar ratio of  HAuCl4 and MoO2 I tried to achieve homogenous decoration with gold nanoparticles with diameter of a few 10 nm. Nanowires decorated with gold were then transformed into MoO3 nanowires decorated with gold by controlled heating in air. With the use of TGA I managed to get the temperature conditions at which the MoO2 nanowires oxidate into MoO3 nanowires while still being decorated with gold. During my work I also used SEM, TEM, XRD.

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