Abstract: An R—Fe—B permanent magnet body is cleaned by ion sputtering, after which a Ti coating film is formed on the surface of the magnet body by a thin film forming method such as ion plating, after which an Al coating film is formed as an intermediate layer, after which an AlN coating film, TiN coating film, or Ti1−xAlxN coating film is formed by a thin film forming method such as ion reactive plating in N2 gas. By having the Al coating film layer present as an intermediate layer, it acts as a sacrificial coating film for the permanent magnet body and the foundation layer Ti coating film, whereupon adhesion with the Ti coating film is sharply improved, and the time until corrosion develops is lengthened, even in such severe corrosion resistance tests as salt water spray tests. Thus R—Fe—B permanent magnets are obtained which exhibit outstanding salt water spray resistance and wear resistance and which have stable magnetic characteristics.

Abstract: A permanent magnet useful in an ultra-high vacuum atmosphere, such as an undulator requiring the ultra-high vacuum atmosphere of less than 1.times.10.sup.-9 Pa and which, has excellent magnetic characteristics, includes an R-Fe-B system permanent magnet having a Ti undercoat layer on a surface thereof, an external layer selected from TiN, AlN and Ti.sub.1-x Al.sub.x N (x is 0.03 to 0.70), and an Al intermediate layer therebetween.

Abstract: A developing agent contains a first wax-containing binder resin having a first wax and a first binder resin, a second wax-containing binder resin having a second wax and a second binder resin, and a coloring material. If the dispersibility of a wax is low because its SP value, molecular weight, or glass transition point is high, combinations of these waxes and resins are so selected that a resin having an SP value close to the SP value of that wax or a resin having a high SP value is combined with that wax.