Maghemite–silica nanocomposites: sol–gel processing enhancement of the magneto-optical response

D Ortega, R García, R Marín, C Barrera-Solano, E Blanco, M Domínguez, M Ramírez-del-Solar
  • Nanotechnology, October 2008, Institute of Physics Publishing
  • DOI: 10.1088/0957-4484/19/47/475706

Seeking the interference-invulnerable current sensor

What is it about?

Electric power transmission companies always look for better means of controlling and delivering electricity through the existing grid. This paper deals with a transparent magnetic nanomaterial suitable for current sensors that could replace the existing ones monitoring electrical grids.

Why is it important?

The scientific literature about silica/iron oxide nanocomposites is plenty of research reporting on their magnetic properties, but those dealing with their applications in magneto-optics are much less numerous. One of the main reasons for this is the difficulty in producing fully functional monolithic composites, the form under which their magneto-optical properties would be usable in technological applications. Sol-gel based methods were considered as a suitable solution for this problem, but the mechanical properties and phase distribution of the as-prepared materials were far from the initial expectations. After four years of research in this particular matter, we succeeded in demonstrating that a washing treatment with ethanol during the sol-gel processing of iron oxide/silica nanocomposites prevents the formation of undesired phases as well as an excessive particle agglomeration. More distinctly, different processing conditions of identical sols may lead to nanocomposites with a Verdet constant similar to that of commercial terbium gallium garnets used in Faraday rotators. Although having a similar performance than the currently chosen materials, the cost reduction introduced by replacing those with the silica-based ones is formidable, and hence the importance of this particular publication.


Dr Daniel Ortega (Author)
IMDEA Nanoscience

This material will be part of better current sensors that may be portable, almost free from external interferences for controlling and delivering electricity through the existing grids.

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The following have contributed to this page: Dr Daniel Ortega