3.5.5 Short application description
Molecular magnetism designates a relatively recent and emerging field that focuses on the use of molecular approaches to design and create new classes of magnetic materials in which the properties can be precisely adjusted at the molecular level. In the last two decades this field has rapidly evolved from the design of new molecule-based magnets possessing higher critical temperatures, towards the development of more complex magnetic materials with one or more functional properties of interest. Developments then have veered toward the investigation of nanosized magnetic molecules and other nanostructures exhibiting quantum effects, to finally process materials for novel applications.
Permanent magnets play a critical role in industry for generation and distribution of electrical power as well as for processing and storing of information. Nanomagnets hold promising possibilities to increase information storage density. Nanomagnets may also be used for medical imaging, drug delivery, sensors technology and computing.
Essential advancement and new developments in the section of high-capacity magnet materials have led to numerous innovation processes in the most different applications. Those mentioned are the engine development, the sensor development and the storage of information. Nanocrystalline alloys can be used in a wide variety of applications in the area of soft magnetic materials.
Despite intense investigation room-temperature magnets made up of molecular components remain rare. These magnets with properties controlled by external forces can be made in entirely new ways. Exemplarily a process leading to unexpected magnetic behaviours was observed in a phase of polymerized C60 by Russian researchers. The unusual stoichiometry and magnetic properties highlight these materials as members of a class of stable magnets located at the interface between conventional inorganic magnets and genuine molecule-based magnets. US researchers have developed a new family of magnetic materials so called exchange-spring magnets. These composites consist of magnetically hard and soft phases which interact by magnetic exchange coupling. Due to the two magnetic phases the composites are stronger than conventional single phase magnets. The hard phase is responsible for high anisotropy and the soft phase for high magnetisation. The requirement for an effective exchange coupling is that both phases have to be controlled at the nanometre scale.
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