Fine acicular alpha -ferric oxide and production thereof

摘要

Disclosed herein is fine acicular alpha -ferric oxide which has the crystallite diameter (D10+E,ovs 1+EE 4) in the direction perpendicular to the (10+E,ovs 1+EE 4) plane and the crystallite diameter (D11+E,ovs 2+EE 0) in the direction perpendicular to the (11+E,ovs 2+EE 0) plane such that their ratio D10+E,ovs 1+EE 4/D11+E,ovs 2+EE 0 is in the range of 1-2, and also has a specific surface area of 40-50 m2g. Disclosed also herein is fine acicular alpha -ferric oxide which has the crystallite diameter (D10+E,ovs 1+EE 4) in the direction perpendicular to the (10+E,ovs 1+EE 4) plane and the crystallite diameter (D11+E,ovs 2+EE 0) in the direction perpendicular to the (11+E,ovs 2+EE 0) plane such that their ratio D10+E,ovs 1+EE 4/D11+E,ovs 2+EE 0 is the range of 1-2, and also has an average aspect ratio of 10-15 and a specific surface area of 20-40 m2/g. They are produced by wet process including the step of hydrothermal reaction.