AsianScientist (Dec. 5, 2014) – Using a combination of layer and pillar magnetic systems, researchers have developed a three-dimensional magnetic framework that paves the way for molecular magnets made purely from organic compounds. This research has been published in Angewandte Chemie.
The advantage of molecular magnets is that they have properties similar to those of plastic instead of metal, making them suitable for applications in new storage media, diagnostics and medical technology. However, this technology is still in its infancy, limited by the fact that most molecular magnets have so far only operated at extremely low temperatures.
In order for a material to become magnetic, there must be an ordered arrangement of the individual molecular magnets which are based on electron spins. However, in systems made from different magnetic building blocks it is not easy to control the magnetic interactions between individual layers or chains.
Dr. Hiroki Fukunaga and Professor Hitoshi Miyasaka at Tohoku University have now produced a three-dimensional structure with long-range magnetic order by combining a two-dimensional layer magnet and a one-dimensional columnar magnetic system.
The magnetic layer consists of paddlewheel-shaped complexes with an axis of two ruthenium ions that are bound to four flat, organic “paddles”. The paddlewheels are bound into continuous layers by means of a flat, organic semiconductor. “Pillars” made of two flat molecules with an iron ion in-between then connect the layers into a three-dimensional lattice.
In the resulting pillared layer framework, the pillars determine the interactions between individual layers. Charge-transfer and other electronic interactions take place between the two individual components, allowing long-range magnetic order within the framework.
The material is magnetic below –191°C (–166°C under pressure). While this still sounds fairly cold, it is actually a relatively high temperature for a molecular magnet, which the researchers take as a good sign.
The article can be found at: Fukunaga and Miyasaka (2014) Magnet Design by Integration of Layer and Chain Magnetic Systems in a π-Stacked Pillared Layer Framework.
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Source: Angewandte Chemie International Edition.
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