Nanomagnet Arrays with Enhanced Magnetic Anisotropy

What is it about?

The implementation of nanomagnets in spintronics, magnetic storage or quantum computing requires the exploration of new materials and fabrication methods that allow the design of uniform nanostructure distributions with convenient magnetic properties. In this work, we explore the self-assembly of cobalt atoms on a modified gold surface as a flexible and efficient approach for the growth of magnetic nanodots. A gadolinium-gold trigon surface structure formed after evaporation of small amounts of Gd on Au(111) surface is used as a template for the subsequent growth of independent Co nanodots. They exhibit an out-of plane easy axis of magnetization and enhanced magnetic anisotropy values compared to other Co nanodots grown on conventional gold surfaces. As the main reason for these magnetic properties the large strain induced by the lattice mismatch at the interface between Co and trigons is discussed. The magnetic behavior of the Co nanodots has been investigated by X-ray magnetic circular dichroism while the structure of the trigon network and the morphology of the Co nanodots have been studies by scanning tunneling microscopy.

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Why is it important?

We present a novel nanotemplate with a hexagonal lattice of 9 nm that can be used as a substrate for magnetic Co nanoparticles. The ordered array of the nanoclusters present enhanced magnetic anisotropy values compared to similar Co nanoparticle arrays. This is an important issue since higher anisotropy values lead to higher critical temperatures of the magnetic properties. A device based on such a nanotemplate would be able to work in a larger temperature range compared to other templates.