Crystal-grain network-structure and magnetic properties of fine α-Fe particles

For fine α-Fe pigments prepared from acicular α-FeOOH(:goethite), the relationship among the intergrain necking-structure and some magnetic properties including typical electro-acoustic tape-performances is studied. According to the preparation-condition, the size and necking-structure of crystal-grain are variously changed and the corresponding skeleton-particle of α-Fe is taken from the necklace to rod-type morphology. The magnetization mechanism is dependent on the particle-morphology. In the case of nearly the same-dimensional skeleton-particles, the recording-tapes prepared from the rod-type particles with smaller-size grains provide the lower bias-noise.