MAGNETIC FLUID AND COLORING MAGNETIC FLUID

摘要

PURPOSE:To obtain a magnetic fluid that assumes a color other than dark brown by using a magnetic metal oxide having a predetermined composition. CONSTITUTION:A magnetic fluid is obtained by dispersing fine particles of a magnetic metal oxide into a solvent. The composition of the magnetic metal oxide satisfies the formula: (MgO)x(ZnO)y(Fe2O3)z, where x, y, and z satisfy the relationship: 0.2<=x<=1.0, 0.9<=z<=1.1, x+y=1. MgZn ferrite and gamma- hematite are red brown whereas CuZn ferrite and NiZn ferrite are dark red brown.