Papers by Author: Jun Akiyama

Abstract: A high magnetic field is a useful tool to control the crystal alignment of ceramic materials. In this study, a horizontal 10T static magnetic field was imposed on slurry containing hydroxyapatite (HAp) crystals under the horizontal mold rotation during slip casting process so as to introduce uni-axial alignment for some amount of crystals in the sample, and then it was sintered in atmosphere without the magnetic field. From X-ray diffraction, it has been found that the HAp crystals in the sample treated with the mold rotation under the magnetic field were aligned its c-axis to a particular direction.

Abstract: Formation of crystallographically orientaed hydroxyapatite (HAp) is one of the promising ways to utilize their anisotropic nature of chemical and biological properties. On the other hand, the development of super conducting magnet technology enables to introduce a high magnetic field which can control crystal orientation of non-magnetic materials with magnetic anisotropy. In this study, a high magnetic field and sample rotation are simultaneously imposed on the hydroxyapatite during a slip casting process in order to align its c-plane within a horizontal plane. From X-ray diffraction, it has been found that the HAp crystals in the sample treated with the magnetic field and the sample rotation were oriented to a particular direction in the slip casting process and it was enhanced by the subsequent sintering process, while the c-axis crystal orientation of the sample treated without the magnetic field and with the sample rotation was not observed before and after the sintering.

Abstract: A high magnetic field is a useful tool to control the crystal alignment of non-magnetic materials such as ceramics and polymers. In the case of Hydroxyapatite crystal, the a,b-axis is aligned parallel to the direction of an imposed magnetic field. This fact implies that the alignment of the c-axis is not controllable only using a high static magnetic field due to the freedom of the c-axis in a plane perpendicular to a magnetic field direction. In this study, a high static magnetic field and mold rotation was simultaneously so applied during a slip casting process as to align the c-axis of HAp poly crystals.