Magnetic Materials, Materials Sciences, magnetic materials exchange-spring magnets soft magnetic materials atom probe field ion microscopy, magnetic materials, nanocrystalline materials, amorphous materials, crystallization, phase trans, nanostructured materials, spintronics, ferromagnetism, semiconductors, synchrotr, nanocomposite magnets atom probr field ion microscopy clustering magnetic properties microalloying a, composite materials, magnetic properties, crystalliz, neutron scatteringfine-particle systemsnanocrystalline materialsmagnetic properties of nanostructure.
Professor Kiyonori Suzuki’s research is primarily directed towards the magnetic properties of non-equilibrium and metastable materials, with particular emphasis placed on nanostructured materials for electromagnetic device applications. The key elements involved in this area of research are nanostructure-magnetic properties relationships, nanostructural formation mechanisms and magnetism in nanostructured systems (e.g., random anisotropy and exchange-spring effects). Major experimental techniques employed in my research include melt-spinning, sputtering, electron microscopy, atomic/magnetic force microscopy, thermal analysis, ac-susceptometry, small-angle neutron scattering and Mössbauer spectroscopy. Successful outcomes from my research in this field include the development of nanocrystalline Fe-M-B (M = early transition metal) soft magnetics alloys (US Patents No. 5449419 and No. 5474624) and the development of a two-phase random anisotropy model. I am also interested in other functional materials in the area of sustainable energy technologies such as hydrogen storage and permeation alloys. Professor Kiyonori Suzuki’s recent research topics are summarised as follows:
Nanostructured soft magnetic materials
Nanocomposite exchange-spring magnets
Magneto-transport properties in magnetic materials
Hydrogen storage and hydrogen-induced effects
Not started projects
An Investigation of Barium Ferrites as Electromagnetic Absorbers
This research project focuses on the feasibility of substituted barium ferrites for use as electromagnetic absorbers. To understand the magnetic loss mechanism with a goal of maximizing the absorption strength and tuning the frequency of absorption through control of the chemical, crystal structure, and morphological properties of Barium Ferrite.
Spin manipulation in oxide magnetic semiconductors towards spintronics applications
The project is to develop high quality diluted magnetic semiconductors (DMS) with magnetic element dopant for practical spintronics applications. The properties for the qualified DMS include intrinsic ferromagnetism, effective spin maipulation, high spin polarization and long distance of spin transport, which have not been well addressed so far. In this project, we will investigate these issues using advance tools, including muon spin relaxation and neutron reflectometry. We expect to establish criteria for evaluating DMS, understanding spin dynamics and mechanisms of spin manipulation and achieve qualified DMSs.
Advanced in-situ electron microscope facility for research in alloys, nanomaterials, functional materials, magnetic materials and minerals
Electron microscopes are key tools for selectively analysing nanostructures, from individual nanoparticles to embedded precipitates. However, the important properties of nanostructured materials are normally measured at the macroscopic level, not at the level of the nanostructure. This Facility will provide a powerful new capability to Australia, enabling the measurement and correlation of structure and properties at the nanoscale and in real time. It will be integrated across Victoria’s three largest electron microscope facilities providing comprehensive in-situ electrical, mechanical and thermal measurements. These capabilities are essential to advance a large range of multidisciplinary research projects at the cutting-edge of science.
Novel method of preparing microstructures in nanocomposite permanent magnets by means of rapid thermal annealing
National Hydrogen Materials Alliance
Intergranular magnetic coupling in multiphase nano-crystalline magnetic materials and its role in improving their soft and hard magnetic properties
Giant magnetic hardening in flash-annealed nano-composite magnets
One of the most important properties required of permanent magnets is the coercivity. Recent results from an international collaboration between the Chief Investigator and researchers from the Japanese materials industry have shown that rapid heating can enhance he coercivity of chormium-added iron-neodymium-boron-based nanocomposite magnets by 30 times. The aim of this project is to clerify the mechanism of this giant magnetic hardening effect and thereby establish a basis for further development of economically viable nanocomposite magnets with low neodymium content. Our novel flash-annealing process will allow exploration of new nanocomposite alloys, which may lead to Australian-owned patents.
Directional atomic ordering in nanocrystalline soft magnetic materials: Development of ultra-efficient magnetic core materials
Soft magnetic materials are used as magnetic cores in electromagnetic devices such as transformers. The latest material development is the use of nanocrystalline soft magnetic alloys. Our theory and experiments have shown that the magnetic softness of nanocrystalline alloys is greatly influenced by directional atomic ordering, which increases magnetic anisotropy and consequently increases heat loss. We will employ a novel magnetic annealing technique to establish the relationship between this anisotropy and the soft magnetic properties of nanocrystalline alloys. Emphasis will be placed on eliminating the induced anisotropy in iron-cobalt based alloys and thereby produce ultra-efficient, magnetic core materials.
Investigation of structural changes in the Nb-TiNi alloys in a hydrogen atmosphere at elevated temperatures
Spin structures of Nanocrystalline hard magnets
Origin of ferromagnetism in zinc-oxide semiconductors: A vital element to spintronics
The realization of ferromagnetism in semiconductors will potentially revolutionize the current electronic devices. The emerging concept underlying this is referred to as spintronics and zinc-oxide doped with transition metal (ZnO:TM) is a promising candidate for a room-temperature ferromagnetic semiconductor for spintronics. However, despite the experimental confirmation of spontaneous magnetization in ZnO:TM, this material remains controversial due to the following open question: Is ZnO:TM truly a ferromagnetic semiconductor or a non-magnetic semiconductor with a ferromagnetic impurity phase? This project will focuses on developing a fundamental understanding of the origin of ferromagnetism in ZnO semiconductor.
Nanostructured magnetic materials for clean automotive technologies
Recent results from an international collaboration between Monash and the Partner Organisation Toyota Motor have shown that the coercivity of manganese-bismuth magnets could be enhanced dramatically by nanoscale grain refinement and the coercivity could exceed the value of the rare-earth based magnets currently used in the petrol-electric hybrid drivetrain at its operation temperature. Our aim is to exploit a range of novel alloy design strategies in manganese-bismuth/iron nanocomposite magnets and thereby developing a new cost effective rare-earth free magnet for low emission technologies. This will be achieved through prevention of the intergranular atomic transport in the two-phase nanocomposites by surfactant-assisted ball milling.
The National Hydrogen Materials Reference Facility
Hydrogen energy technology is a vital element in the global response to climate change owing to increasing atmospheric carbon dioxide levels from burning fossil fuels. Hydrogen is a universal energy carrier that facilitates the transformation of energy from renewable and other sources for applications in industry, transport and homes. The National Hydrogen Materials Reference Facility is a multidisciplinary, state-of-the-art experimental facility for materials science supporting excellent research into advanced materials for hydrogen generation from fossil fuels and by solar means, hydrogen storage for automotive and stationary applications, hydrogen distribution and hydrogen end use, particularly in fuel cells that generate electricity.
Novel nanostructured alloy membranes for hydrogen permeation: Advanced materials technology for renewable energy
Hydrogen permeation alloy membranes are atomic sieves which allow only hydrogen atoms to permeate, making them vital to efficient hydrogen generation from biomass or gasified coal. A drawback of the current membrane separation technology is that the alloys used are mostly based on costly palladium. Our recent discovery of novel successful approaches to the design of niobium-based hydrogen permeation alloys will be systematically exploited to develop new palladium-free nanocomposite hydrogen permeation membranes with enhanced hydrogen separation capability.
A feasibility study of rare-earth free permanent magnets based on MnBi/Fe nanocomposites