Polarization Analyzed Small Angle Neutron Scattering Of Ferrite Nanoparticles

Ferromagnetic nanoparticles offer a range of possible applications in nanotechnology, biomedical practices, and data storage, but important issues exist regarding their true magnetic structure. We have been investigating 9 nm diameter Fe3 O4 nanoparticles and 11 nm diameter CoFe2 O4 nanoparticles coated with an oleic acid shell. The nanoparticles were synthesized by solution chemistry methods and characterized by X-ray diffraction, SQUID, and vibrating sample magnetometry. Polarization Analyzed Small Angle Neutron Scattering (PASANS) was used under various temperatures and applied magnetic fields to investigate the magnetic structure of the particles. PASANS has revealed the iron oxide particles have a canted magnetic shell in high field that disappears in lower field, while the cobalt iron oxide particles are fully canted. We have developed an energy-based model to explain the origins of this canting and shell formation that agrees with the experimental results.

Ferrite Nanostructured Magnetic Materials: Technologies and Applications provides detailed descriptions of the physical properties of ferrite nanoparticles and thin films. Synthesis methods and their applications in numerous fields are also included. And, since characterization methods play an important role in investigating the materials’ phenomena, various characterization tools applied to ferrite materials are also discussed. To meet the requirements of next-generation characterization tools in the field of ferrite research, synchrotron radiation-based spectroscopic and imaging tools are thoroughly explored.Finally, the book discusses current and emerging applications of ferrite nanostructured materials in industry, health, catalytic and environmental fields, making this comprehensive resource suitable for researchers and practitioners in the disciplines of materials science and engineering, chemistry and physics. Reviews the fundamentals of ferrite materials, including their magnetic, electrical, dielectric and optical properties Includes discussions on the most relevant and emerging synthesis and optimization of ferrite nanostructured materials for a diverse range of morphologies Provides an overview of both the most relevant and emerging applications of ferrite magnetic materials in industry, health, energy and environmental remediation

Magnetic Small-Angle Neutron Scattering provides the first extensive treatment of magnetic small-angle neutron scattering (SANS). The theoretical background required to compute magnetic SANS cross sections and correlation functions related to long-wavelength magnetization structures is laidout. The concepts are scrutinized based on the discussion of experimental neutron data. Regarding prior background knowledge, some familiarity with the basic magnetic interactions and phenomena as well as scattering theory is desired.Besides exposing the different origins of magnetic SANS, and furnishing the basics of the magnetic SANS technique in early chapters, a large part of the book is devoted to a comprehensive treatment of the continuum theory of micromagnetics, as it is relevant for the study of the elastic magneticSANS cross section. Analytical expressions for the magnetization Fourier components allow to highlight the essential features of magnetic SANS and to analyze experimental data both in reciprocal, as well as in real space. Later chapters provide an overview on the magnetic SANS of nanoparticles andso-called complex systems (e.g., ferrofluids, magnetic steels, spin glasses and amorphous magnets). It is this subfield where major progress is expected to be made in the coming years, mainly via the increased usage of numerical micromagnetic simulations (Chapter 7), which is a very promisingapproach for the understanding of the magnetic SANS from systems exhibiting nanoscale spin inhomogeneity.

The technique of small angle neutron scattering (SANS) is ideally suited for determining the length scale of magnetic correlations in nanocrystalline materials. The additional use of polarized neutrons also allows for a clear separation between magnetic and non-magnetic scattering. The temperature dependence of the SANS cross-section from a two-phase alloy, consisting of both amorphous and nano-crystalline parts, Fe89Zr7B3Cu1, has been measured in the temperature range from 293 to 500 K. The SANS measurements are accompanied by bulk magnetization and Mossbauer transmission data. In this range of temperatures, the magnetic contrast between the nanocrystalline and amorphous phases, which are both magnetic, changes dramatically. This phase contrast increases up to 380 K, which is the proposed decoupling temperature for the inter-granular exchange stiffness. Above this temperature, the contrast levels off slowly, being totally dominated by the decreasing magnetization of the nanocrystalline phase.

The manipulation and control of cells and sub-cellular structures through magnetic nanoparticle-based actuation is a relatively new technique that has led to novel and exciting biomedical applications. Nanomagnetic actuation is being used in laboratory studies of stem cells to determine how these mechanical cues can be used to control stem cell differentiation for regenerative medicine applications. This book explores this rapidly expanding field. It will interest industry bioscientists and biomedical engineers as well as academics in cellular biomechanics, cell and tissue engineering, and regenerative medicine. Key Features Focuses on the fundamentals and applications of magnetic actuation Includes contributions by world-class researchers from several countries and is edited by a well-known researcher in this field Offers multidisciplinary coverage and applications Supplies extensive references at the end of each chapter

This research monograph presents the latest results related to the characterization of low dimensional systems. Low-angle polarized neutron scattering and X-ray scattering at grazing incidence are used as the two main techniques to explore various physical phenomena of these systems. Special focus is put on systems like thin film transition metal and rare-earth layers, oxide heterostructures, hybrid systems, self-assembled nanostructures and self-diffusion. Readers will gain in-depth knowledge about the usage of specular scattering and off-specular scattering techniques. Investigation of in-plane and out-of-plane structures and magnetism with vector magnetometric information is illustrated comprehensively. The book caters to a wide audience working in the field of nano-dimensional magnetic systems and the neutron and X-ray reflectometry community in particular.

Research into the fascinating properties and applications of magnetic fluids - also called ferrofluids - is rapidly growing, making it necessary to provide, at regular intervals, a coherent and tutorial account of the combined theoretical and experimental advances in the field. This volume is an outgrow of seven years of research by some 30 interdisciplinary groups of scientists: theoretical physicists describing the behaviour of such complex fluids, chemical engineers synthesizing nanosize magnetic particles, experimentalist measuring the fluid properties and mechanical engineers exploring the many applications such fluids offer, in turn providing application-guided feedback to the modellers and requests for the preparation of new fluid types to chemists, in particular those providing optimum response to given magnetic field configurations. Moreover, recent developments towards biomedical applications widens this spectrum to include medicine and pharmacology. Consisting of six large chapters on synthesis and characterization, thermo- and electrodynamics, surface instabilities, structure and rheology, biomedical applications as well as engineering and technical applications, this work is both a unique source of reference for anyone working in the field and a suitable introduction for newcomers to the field.