| 摘要 |
A crystalline ferromagnetic material based upon nanoscale cobalt carbide particles and a method of manufacturing the material via a polyol reaction are disclosed. The crystalline ferromagnetic cobalt carbide nanoparticles are useful for high performance permanent magnet applications. The processes are extendable to other carbide phases. Fe- and FeCo-carbides are realizable by using as precursor salts Fe-, Co-, and mixtures of Fe- and Co-salts, such as acetates, nitrates, chlorides, bromides, citrates, and sulfates. The materials include mixtures and/or admixtures of cobalt carbides, as both Co2C and Co3C phases. Mixtures may be a collection of independent particles of Co2C and Co3C or a collection of particles which consist of an intimate combination of Co2C and Co3C phases within individual particles. The relative proportions of these two phases and the morphology of each phase contribute to their permanent magnet properties, particularly at room temperature to over 400 K. |
