A broad range of applications of magnetic nanostructures have been developed in recent years. Magnetic data storage, microelectronics, or biomedical uses such as cell separation or biosensing present a special interest among these applications. Atomic layer deposition (ALD) is a very suitable method for the conformal deposition of magnetic films in pore structures of high aspect ratio, while offering the precise tuning of the layer thickness and high uniformity.

For the ALD of Co and Ni, a metal oxide film has been grown initially by the reaction of CoCp2 (cobaltocene) or NiCp2 (nickelocene) with ozone. Subsequently, the metal oxide film has been reduced in hydrogen atmosphere after the ALD process and converted to the metallic ferromagnetic phase with low-degree of surface roughness. In a similar manner, Fe₃O₄ films have been grown by the ALD deposition of Fe₂O₃ films based on the reaction of water and iron(III) tert-butoxide (Fe₂(OtBu)₆) and followed by a hydrogen reduction. On the other hand, we have observed that direct reaction of a metal-organic precursor and hydrogen during the ALD cycle always yields very granular films with ill-defined magnetic properties and low deposition rates (<0.1 Å/cycle).

By conformal coating of self-ordered Al₂O₃ membranes, arrays of magnetic nanotubes with diameters down to 20 nm and wall thicknesses of <3 nm have been achieved. The magnetic properties of the nanotube arrays as a function of wall thickness and tube diameter have been studied by using SQUID magnetometry and compared with magnetic simulations. As an outlook we will discuss the properties of magnetic multi-layer nanotubes (core-shell) and the application of conformal magnetic coatings of other template systems and 3D nanostructures.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/11357 must be provided.

1. Hierarchical 3D ZnO and their shape-preserving transformation into zinc spinel nanostructures
2. Nanopores and Nanowires
3. Functional Nanostructured Coatings by Molecule-based PECVD Techniques
4. (Bio)organic-Inorganic Hybrid Nanostructures by ALD
5. Protective and Bio-compatible Nanostructured Surfaces by CVD Techniques: Controlled Modulation of Surface and Phase Structures
6. Lithium Niobate Nano- and Microtubes