Formation of c-axis Aligned Polycrystal Hydroxyapatite Using High Magnetic Field with Mechanical Sample Rotation

Abstract

It is possible to control the crystal alignment of non-magnetic materials such as anisotropic ceramics and polymeric materials using a high magnetic field. However, the alignment of the c-axis direction in hexagonal crystals, with a magnetic susceptibility of χ_c<χ_a,b, is uncontrollable using a static magnetic field, because the c-axis can rotate in the plane perpendicular to the direction of the magnetic field. In this study, a high magnetic field and mechanical rotation are simultaneously imposed on a sample in order to align crystals parallel to that axis (c-axis) which has small magnetic susceptibility. This process of alignment was applied to hydroxyapatite (HAp) crystals and a sample was obtained, in which the c-axis of the HAp crystals aligned in a particular direction.