Hitachi Chemical Company, Ltd.

Hitachi, Ltd.

Shigeaki Funyu

Matahiro Komuro

Yuichi Satsu

Yoshii Morishita

Mitsuo Katayose

An R&#x2014;Fe&#x2014;B sintered magnet has a structure including main phase crystal grains and a grain boundary area surrounding the crystal grains. The sintered magnet includes fluorine and a specified metal element selected from elements belonging to Group 2 through Group 16 of periodic table excepting the rare earth element, carbon and boron. The fluorine has a higher concentration in a region closer to a magnet surface than in the center. The specified element also has a higher concentration in the region closer to the surface. The sintered magnet includes oxyfluoride containing carbon, Dy and the metal element in a grain boundary area region at a distance of 1 &#x3bc;m or greater from the magnet surface, and the carbon has a higher concentration than the concentration of the metal element in a region at a distance of 1 &#x3bc;m to 500 &#x3bc;m from the magnet surface.

Rotating machine with sintered magnet and method for producing sintered magnet

A fluoride coating film formed with a fluoride-containing solution wherein a rare earth fluoride or an alkaline earth metal fluoride, in particular, fluoride of Pr, Nd, Dy, Tb and Ho, is swollen in a solvent comprising a major amount of an alcohol, and the solution is a colloidal solution in which the rare earth fluoride or the alkaline earth metal fluoride is dispersed homogeneously in the solvent comprising a major amount of an alcohol improves magnetic properties of NdFeB rare earth magnets including not only sintered magnets but also bonded magnets.

Growing community of inventors

Tsuchiura, Japan

Shigeaki Funyu