Magnetic recording medium having a dimensional variation
摘要
說明書
The magnetic powder includes a powder of nanoparticles containing an ε-iron oxide (hereinafter referred to as “ε-iron oxide particles”). Even if the ε-iron oxide particles are fine particles, a high coercive force can be obtained. Preferably, the ε-iron oxide contained in the ε-iron oxide particles preferentially have crystals oriented in the thickness direction (vertical direction) of the magnetic recording medium 10.
The ε-iron oxide particles have a spherical shape or a substantially spherical shape, or have a cubic shape or a substantially cubic shape. The ε-iron oxide particles have the shape as mentioned above, and thus, in a case where the ε-iron oxide particles are used as magnetic particles, the area of contact between the particles in the thickness direction of the medium can be reduced, thereby inhibiting the aggregation of the particles, as compared with a case of using hexagonal plate-shaped barium ferrite particles as magnetic particles. Thus, the dispersibility of the magnetic powder can be enhanced, thereby providing a more favorable signal-to-noise ratio (SNR).
The ε-iron oxide particles have a core-shell type structure. Specifically, as shown in
The core part 21 contains an ε-iron oxide. The ε-iron oxide contained in the core part 21 preferably has an ε—Fe2O3 crystal as a main phase, and more preferably a single-phase ε—Fe2O3.
