Plasma Synthesis And Self Assembly Of Magnetic Nanoparticles

Nanomaterials are important tools for enabling technological progress as they can provide dramatically different properties as compared to the bulk counterparts. The field of nanoparticles is one of the most investigated within nanomaterials, thanks to the existing, relatively simple, means of manufacturing. In this thesis, high-power pulsed hollow cathode sputtering is used to nucleate and grow magnetic nanoparticles in a plasma. This sputtering technique provides a high degree of ionization of the sputtered material, which has previously been shown to aid in the growth of the nanoparticles. The magnetic properties of the particles are utilized and makes it possible for the grown particles to act as building blocks for self-assembly into more sophisticated nano structures, particularly when an external magnetic field is applied. These structures created are termed “nanowires” or “nanotrusses”, depending on the level of branching and inter-linking that occurs. Several different elements have been investigated in this thesis. In a novel approach, it is shown how nanoparticles with more advanced structures, and containing material from two hollow cathodes, can be fabricated using high-power pulses. The dual-element particles are achieved by using two distinct and individual elemental cathodes, and a pulse process that allows tuning of individual pulses separately to them. Nanoparticles grown and investigated are Fe, Ni, Pt, Fe-Ni and Ni-Pt. Alternatively, the addition of oxygen to the process allows the formation of oxide or hybrid metal oxide – metal particles. For all nanoparticles containing several elements, it is demonstrated that the stoichiometry can be easily varied, either by the amount of reactive gas let into the process or by tuning the amount of sputtered material through adjusting the electric power supplied to the different cathodes. One aim of the presented work is to find a suitable material for the use as a catalyst in the production of H2 gas through the process of water splitting. H2 is a good candidate to replace fossil fuels as an energy carrier. However, rare elements (such as Ir or Pt) needs to be used as the catalyst, otherwise a high overpotential is required for the splitting to occur, leading to a low efficiency. This work demonstrates a possible route to avoid this, by using nanomaterials to increase the surface-to-volume ratio, as well as optimizing the elemental ratio between different materials to lower the amount of noble elements required.

Timely and comprehensive, this book presents recent advances in magnetic nanomaterials research, covering the latest developments, including the design and preparation of magnetic nanoparticles, their physical and chemical properties as well as their applications in different fields, including biomedicine, magnetic energy storage, wave-absorbing and water remediation. By allowing researchers to get to the forefront developments related to magnetic nanomaterials in various disciplines, this is invaluable reading for the nano, magnetic, energy, medical, and environmental communities.

This interdisciplinary approach to the topic brings together reviews of the physics, chemistry, fabrication and application of magnetic nanoparticles and nanostructures within a single cover. With its discussion of the basics as well as the most recent developments, and featuring many examples of practical applications, the result is both a clear and concise introduction to the topic for beginners and a guide to relevant comprehensive physical phenomena and essential technological applications for experienced researchers.

Magnetic Nanoparticles Learn how to make and use magnetic nanoparticles in energy research, electrical engineering, and medicine In Magnetic Nanoparticles: Synthesis, Characterization, and Applications, a team of distinguished engineers and chemists delivers an insightful overview of magnetic materials with a focus on nano-sized particles. The book reviews the foundational concepts of magnetism before moving on to the synthesis of various magnetic nanoparticles and the functionalization of nanoparticles that enables their use in specific applications. The authors also highlight characterization techniques and the characteristics of nanostructured magnetic materials, like superconducting quantum interference device (SQUID) magnetometry. Advanced applications of magnetic nanoparticles in energy research, engineering, and medicine are also discussed, and explicit derivations and explanations in non-technical language help readers from diverse backgrounds understand the concepts contained within. Readers will also find: A thorough introduction to magnetic materials, including the theory and fundamentals of magnetization In-depth explorations of the types and characteristics of soft and hard magnetic materials Comprehensive discussions of the synthesis of nanostructured magnetic materials, including the importance of various preparation methods Expansive treatments of the surface modification of magnetic nanoparticles, including the technical resources employed in the process Perfect for materials scientists, applied physicists, and measurement and control engineers, Magnetic Nanoparticles: Synthesis, Characterization, and Applications will also earn a place in the libraries of inorganic chemists.

This comprehensive book set includes four volumes, covering the methods and protocols for the synthesis, fabrication, and characterization of nanomaterials. The first two books introduce the solution phase and gas synthesis approaches for nanomaterials, providing a number of most widely used protocols for each nanomaterial. An exhaustive list of nanomaterials are included, which are arranged according to the atomic number of the main element in the compound for easy search. For each material, the protocols are categorized according to the morphology of the nanostructure. A detailed reference is included in each protocol to point the readers to the source of the protocol. The third book describes many unconventional methods for the fabrication of nanostructures, including lithography and printing, self-assembly, chemical transformation, templated synthesis, electrospinning, laser induced synthesis, flame and plasma synthesis, and atomic layer deposition processes. The fourth book covers the typical methods for structural characterization of nanomaterials, including electron diffraction, electron microscopy, atomic force microscopy, scanning tunneling microscopy, X-ray diffraction, in-situ and operando X-ray techniques, X-ray absorption fine structure spectroscopy, static and dynamic light scattering, vibrational characterization methods, and NMR spectroscopy. In addition to the introduction of the basic operational principles of these tools, the book focuses explicitly on how they can be applied for analyzing nanomaterials. The handbook is a complete reference that can provide readers easily accessible information on how to synthesize and characterize nanomaterials desired for their target applications.

Top-down approaches are currently the main contributor of fabricating microelectronic devices. However, the prohibitive cost of numerous technological steps in these approaches is the main obstacle to further progress. Furthermore, a large number of applications necessitate fabrication of complex and ultra-small devices that cannot be made using these approaches. New approaches based on natural self-assembly of matter need to be developed to allow for fabrication of micro and nanoelectronic devices. Self-assembly of nanostructures is a dynamic field, which explores physics of these structures and new ways to fabricate them. However, the major problem is how to control the properties of the nanostructures resulting from low dimensionality. This book presents recent advances made to address this problem, and fabricate nanostructures using self-assembly.

Magnetic nanoparticles have been attracting much interest in the fields of advanced biological and medical applications such as drug delivery, magnetic resonance imaging, and array-based assaying as well as in the fields of separation science. This book presents current research in the study of the properties, synthesis and applications of magnetic nanoparticles. Topics include the synthesis of organic based magnetic nanoparticles-polymers and calixarene based magnetic nanoparticles; ferromagnetism in carbon and boron nitride nanostructures; and computer simulations, chemical syntheses and biomedical diagnosis using magnetic nanoparticles.

The book series Nanomaterials for the Life Sciences, provides an in-depth overview of all nanomaterial types and their uses in the life sciences. Each volume is dedicated to a specific material class and covers fundamentals, synthesis and characterization strategies, structure-property relationships and biomedical applications. The series brings nanomaterials to the Life Scientists and life science to the Materials Scientists so that synergies are seen and developed to the fullest. Written by international experts of various facets of this exciting field of research, the series is aimed at scientists of the following disciplines: biology, chemistry, materials science, physics, bioengineering, and medicine, together with cell biology, biomedical engineering, pharmaceutical chemistry, and toxicology, both in academia and fundamental research as well as in pharmaceutical companies. VOLUME 4 - Magnetic Nanomaterials This volume takes the reader on a tour showing how magnetic nanomaterials are used in the fields of diagnosis and therapy, as well as in tissue engineering and environmental applications.