Particles containing iron carbide.

摘要

The present invention provides acicular particles containing an iron carbide which are obtained by heating an aqueous dispersion of ferric hydroxide in an alkaline system in the presence of a water-soluble compound capable of coordinating to iron to obtain acicular alpha -ferric oxide and contacting the product with a carbon-containing reducing-and-carburizing agent or with a mixture of the agent and a carbon-free reducing agent, with or without contacting the product with the carbon-free reducing agent. These particles are controllable in coercive force and usable for magnetic record media of various standards.