Faculty of Engineering


Research Highlights

Materials Innovation through Magnetic Flux Control

There is a common misconception that some materials and substances are “non-magnetic” and do not respond to magnets at all, but in truth, everything is magnetic to a certain extent.

In primary school, most of us learn that certain objects like coins or water do not show responses to magnets, and their non-magnetism is presented as fact in children’s textbooks. However, when introduced to magnetic fields that are 100 or 1000 times stronger, these substances do, in fact, demonstrate a magnetic response.

When exposed to a sufficiently strong magnetic field, water is shown to be magnetically repulsive and aluminum to be attractive. The magnets we use in everyday life are not nearly strong enough to produce a visually observable reaction, but even so, the response of things like water and aluminum to magnets should be understood as “extremely weak” rather than “unresponsive”. Moreover, one can recognize that all materials and substances show some magnetic properties, and these should be referred to as “feeble magnetic” substances rather than “non-magnetic” substances.

Given that all materials are magnetic on some level, by introducing them to a magnetic field of sufficient intensity, we can expect them to demonstrate some visually observable response. In 1994, a Japanese company developed cryogen-free superconducting solenoidal electromagnets capable of producing a high magnetic field of 10 teslas while only requiring electric refrigeration, thereby foregoing the need for rare and expensive liquid helium. Thus, experiments using high-intensity magnetic fields were made much easier to perform, and allowed more researchers to contribute to the creation of a new field: “magnetoscience”.

At the current stage, our magnetoscience research group at KUAS focuses on material-production processes, with “magnetic alignment” being one of our main research projects. Our laboratory has a sophisticated superconducting electromagnet, which can generate a 10 tesla-class magnetic field, and a newly developed arranged magnet specialized for magnetic alignment work. We are also studying the crystal orientation of functional ceramics with anisotropic crystal structures. Our group also focuses on the development of materials appropriate for magnetic alignment. Enhancing the magnetic anisotropies of substances directly leads to a reduction of in the magnetic field required for magneticalignment, which is strongly related to the specification and cost of magnets. In this context, knowledge of solid-state chemistry and inorganic chemistry is useful.

The photograph below is an example of a tri-axial magnetic alignment using a modulated rotating magnetic field (MRF) generated by a superconducting electromagnet. The photograph shows a magnetically aligned sample of oxide-based superconductor crystals cured in transparent epoxy resin under a 10-tesla MRF at room temperature. The shape of the crystals is a plate-like cuboid and, in the photograph, the surfaces of the crystals with the largest area are aligning along the longest their longest axis. All of the crystals are well aligned, and this is obvious evidence of tri-axial magnetic alignment under MRF. In the case of epitaxy-based crystal growth, precise control of temperature and highly aligned templates are indispensable for obtaining such crystals. However, magnetic alignment can be achieved at room temperature without a highly aligned template or precise temperature control. This magnetoscientific technique, based on superconducting electromagnets, has the potential to become a standard production process for materials and to contribute to the next generation of materials innovation.