RARE EARTH PERMANENT MAGNET

文件类型：PDF文档
文件大小：128K
PROBLEM TO BE SOLVED : To provide a rare earth permanent magnet having sufficient corrosion resistance. SOLUTION : The rare earth permanent magnet 1 consists of a magnet element 3, and a protective layer 5 formed to cover the entire surface of the magnet element 3 wherein the protective layer 5 includes a first layer 2, a second layer 4 and a third layer 6 sequentially from the magnet element 3 side. The first layer is a layer containing at least a rare earth element, iron and oxygen. The second layer contains at least a rare earth element and oxygen wherein the content ratio of rare earth element to iron is larger than that in the first layer. The third layer contains at least iron and oxygen and the content ratio of rare earth element to iron is smaller than that in the first layer. COPYRIGHT : (C)2007, JPO&INPIT