Magnetic nanoparticles (NPs) are finding their place in many modern technologies such as electronics (memory or spintronic devices) and medicine (contrast media, electromagnetic thermal therapy) to name just a few examples. The application of modern techniques based on synchrotron radiation, in particular X-ray spectroscopies, as well as an rf transverse susceptibility probe, built ad hoc, allowed the author to investigate several classes of magnetic NPs with diverse applications. For example, the interesting anisotropic properties of CoW and CoPt NPs revealed new magnetic behaviour and phases. Gold NPs prepared on a biological template from Sulfolobus acidocaldarius S-layer, were shown to possess intrinsic magnetism caused by the electron exchange with the sulfur atoms of the template. Silica and oleic acid coated magnetite NPs showed excellent human compatibility while preserving the bulk magnetic figures of merit. Both macroscopic and microscopic properties of all these NPs, hitherto unexplained, have been revealed for the first time.

Nominated as an outstanding Ph.D. thesis by Universidad de Zaragoza, Spain Provides both macroscopic and microscopic studies of several magnetic nanoparticle systems including granular multilayer films, biological gold nanoparticles and particles for biomedical applications Presents a novel design of the RF transverse susceptibility setup used for direct measurements of magnetic anisotropy Includes supplementary material: sn.pub/extras

Autorentext
A. I. Figueroa obtained her B.S. degree in Engineering Physics at the Universidad del Cauca in Popayan, Colombia in 2008. Then she moved to Zaragoza, Spain where she completed her M. Sc. in Physics in 2009 and her Ph.D. in 2012. She is currently a postdoctoral researcher in the Magnetic Spectroscopy Lab of Diamond Light Source, the UK national synchrotron, in Oxfordshire. Her scientific interests are spintronics, magnetic materials and synchrotron radiation techniques applied to magnetism studies.

Inhalt
Introduction.- Experimental Techniques.- Structural and Magnetic Properties of Amorphous Co-W Alloyed Nanoparticles.- Breakdown of Hund's Third Rule in Amorphous Co-W Alloy Nanoparticles.- Structural and Magnetic Properties of Co-Pt Nanoparticles.- d-band Magnetism of Ag, Au, Pd and Pt Nanostructured Materials.- Transverse Susceptibility Measurement System for the PPMS.- Transverse Susceptibility of Iron Oxide Nanoparticles Systems.- General Conclusions.