Abstract: In a hermetic vessel filled with hydrogen gas, a sodium borate and aluminum powder are reacted at not less than 400° C. and not more than 560° C. while performing stirring to produce sodium borohydride with the molar ratio of sodium contained in the sodium borate being larger than 0.5 relative to boron contained in the sodium borate.

Abstract: A sodium borate, aluminum powder and fluoride powder are mixed together in a hermetic vessel filled with hydrogen gas, and the mixture is reacted at not less than 410° C. and not more than 560° C. to produce sodium borohydride.

Abstract: According to the present invention, a magnetic recording medium is provided including a disk-shaped non-magnetic substrate and at least a perpendicular magnetic layer formed on the disk-shaped non-magnetic substrate, wherein the perpendicular magnetic layer has a structure in which an FePt or CoPt nanoparticle array is formed on a formation surface, on which a plurality of striations each having a circumferential directional component are formed, by a texturing treatment; a manufacturing method thereof; and a magnetic record/reproduction apparatus including the magnetic recording medium or a magnetic recording medium manufactured according to the manufacturing method.

Abstract: According to the present invention, a magnetic recording medium is provided including a disk-shaped non-magnetic substrate and at least a perpendicular magnetic layer formed on the disk-shaped non-magnetic substrate, wherein the perpendicular magnetic layer has a structure in which an FePt or CoPt nanoparticle array is formed on a formation surface, on which a plurality of striations each having a circumferential directional component are formed, by a texturing treatment; a manufacturing method thereof; and a magnetic record/reproduction apparatus including the magnetic recording medium or a magnetic recording medium manufactured according to the manufacturing method.

Abstract: A high density magnetic recording medium including aggregates of magnetic nanoparticles arranged stably and efficiently in demarcated sections in the surface of a substrate is manufactured by the steps of forming a plurality of parallel tracks in the surface of the substrate, forming a plurality of minute recesses serially at approximately equal intervals in each of the tracks, casting a liquid dispersion of magnetic nanoparticles into the minute recesses, and evaporating dispersing medium from the liquid dispersion, thereby forming an aggregate of magnetic nanoparticles in each of the minute recesses.