極薄磁性層を有する塗布型磁気記録媒体用メタル粒子の構造と磁気特性について The Structure and Magnetic Properties of Metal Particles for Advanced Thin Layer Metal Particulate Media
Metal particles, which are developing as advanced thin layer metal particulate media, have a coercive force of 167 to 191kA/m and a particle length of 60 to 80 nm. The particle form and its inner structure were examined with high resolution transmission electron microscopy and magnetic properties of these magnetic media. The particle length distribution which was defined as the standard deviation divided by the average length, was improved about 0.6 times of conventional metal particles.<BR>The coercive force decreased with increasing particle length as well as aspect ratio(length/width). The value of rotational hysteresis integral was close to 1.1 with increasing the content of metal particles consisted of a single metal crystallite.<BR>Larger content of single crystal metal particles or smaller number of metal crystallites in a metal particle seems to cause magnetization reversal similar to the coherent mode and large coercive force of 167kA/m or above. The enhanced characteristics of metal particle for extremely thin layer metal particulate media were achieved by the improvement of particle size and the particle size distribution of starting materials, and also the higher densification in the metal manufacturing processes.<BR>There is still great room for improvement in the properties of metal particles which may be contributed to the extremely high density magnetic recording.
粉体および粉末冶金 43(8), 961-965, 1996-08-15
Japan Society of Powder and Powder Metallurgy