Abstract: The cleaning method of the present invention comprises; (a) immersing a material to be cleaned in a mixed solvent contained in the first open vessel, wherein the mixed solvent consists of a chlorofluoro-hydrocarbon with a boiling point of 20.degree.-50.degree. C. and an organic solvent with a boiling point of 50.degree. C. or more higher than that of said chlorofluoro-hydrocarbon and compatible therewith, but not azeotropic therewith, and kept at a temperature within a range between the boiling point of the chlorofluoro-hydrocarbon and a temperature of at least 30.degree. C.

Abstract: A mixed cleaning solvent containing dichlorotrifluoroethane and dimethoxymethane without containing Flon #113, which is suitable for cleaning and degreasing printed circuit boards and for eliminating flux residues and dust particles adhering thereon and which reveals high cleaning ability without occurrence of whity specks of volatilization residues including ionic residues on the treated surface with possible attainment of high stability to decomposition of the solvent component.

Abstract: A tilting mechanism tilts the wafer holding portions for wafers in any direction with respect to the direction of ion beams emitted from an ion source. The tilting mechanism is comprised of a linking mechanism for transmitting the rotation of the receiving plates to the wafer holding portions, tilted links for tilting the wafer holding portions, and a shaft being coupled to the tilted links and moving in the rotary disc. The wafer holding portions provide spherical portions, and the spherical portions are inserted in the receiving plates. A pin of the preceiving plates is fitted into the groove of the wafer holding portion. The distances between the ion source and the respective wafers are maintained equal. The ion beam irradiates uniformly the respective wafers and treats uniformly the respective wafers.

Abstract: The invention provides a method for producing a magnetic bias field in a magnetic bubble domain memory device. The method comprises coupling a magnetic bubble domain element with a permanent magnet. The permanent magnet is formed of a rare earth metal-containing alloy for use in the bubble domain memory device in respect of the reversible temperature coefficient of the magnet capable of being in compliance with the temperature coefficient of the bubble disappearance field of the memory device. The alloy characteristically contains nickel as an essential component so that the composition of the alloy is expressed by the formulaR(Co.sub.1-x-y Cu.sub.x Ni.sub.y).sub.z,in which R is a rare earth element, e.g. samarium or cerium, and s, y and z are each a positive number from 0.001 to 0.4, from 0.001 to 0.6 and from 4.0 to 9.0, respectively, with the proviso that x+y is smaller than 1.

Abstract: Permanent magnets are disclosed having a very high coercive force and a very great maximum energy product, and consisting essentially of a rare earth-cobalt based alloy. The alloy is expressed by the formula Sm.sub.1.sub.-u Ce.sub.u (Co.sub.1.sub.-v.sub.-w.sub.-x Cu.sub.v Fe.sub.w Mn.sub.x).sub.z where 0.ltoreq.u.ltoreq.0.20, 0.08.ltoreq.v.ltoreq.0.20, 0.ltoreq.w.ltoreq.0.08, 0.01.ltoreq.x.ltoreq.0.15 and 6.0.ltoreq.z.ltoreq.7.8, preferably 7.2.ltoreq.z.ltoreq.7.8. By using these alloys, the magnetic properties of the resultant permanent magnets are superiorly affected, and the magnet-preparing process is rendered much simplified. This is also because the conventional heat aging step may be eliminated, particularly when the z value is within the preferred range.