| 摘要 |
PURPOSE:To manufacture a coating type optomagnetic recording medium having large magneto-optical effect, high density recording and small light scattering of the medium by dispersing or dissolving rare earth element iron garnet fine particles coated with oil soluble surfactant together with binder in organic solvent. CONSTITUTION:Solution containing element ions selected at a ratio for forming a rare earth element iron garnet represented by a formula RaBibFecMdOe and alkali hydroxide are so mixed that alkali hydroxide concentration after mixture become 0.1-8mol/l to generate precipitate, which is baked at 600-900 deg.C to obtain rare earth element iron garnet fine particles. The particles are coated with oil soluble surfactant. In the formula, R is a rare earth element selected from a group consisting of Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. M is an element substituted for iron. The average particle size of the particle is 30-1000Angstrom . If the particle size is smaller than 30Angstrom , it becomes superparamagnetic due to heat disturbance, while if it exceeds 1000Angstrom , light is scattered to generate noise. |
