Abstract: A ferromagnetic material is composed of an iron alloy which contains 2 to 12% by weight of silicon and 5 to 25% by weight of at least one element selected from the group consisting of ruthenium, rhodium, palladium, iridium, platinum, gold and silver. This ferromagnetic material exhibits a high saturation flux density and good corrosion resistance. Excellent magnetic characteristics are obtained by a multilayered film which is obtained by alternatingly laminating the above ferromagnetic material and a spacer layer composed of other material. Further, a markedly increased recording density is exhibited by a magnetic head for perpendicular magnetic recording, when the end of the main pole is composed of the ferromagnetic material.

Abstract: A multilayered ferromagnetic amorphous alloy film is constituted by a plurality of main ferromagnetic material alloy films of a ferromagnetic amorphous alloy laminated one upon another with a spacer ferromagnetic material layer interposed therebetween, the spacer ferromagnetic material layer being of a ferromagnetic material different from the ferromagnetic alloy. Also disclosed is a magnetic head employing the above-described multilayered film for, at least, a portion of a core thereof. The multilayered film has excellent magnetic characteristics and is easily patterned.

Abstract: A thin-film magnetic head which has a structure wherein a spiral conductor coil having a plurality of turns is disposed between first and second magnetic layers being substantially in parallel with each other, through upper and lower inorganic insulator layers, and in which a part of the outermost turn of the conductor coil is exposed on a face opposite a magnetic recording medium along with the upper and lower inorganic insulator layers, to form a magnetic gap. This head can be readily manufactured by a manufacturing method including the step of forming the outermost turn of the conductor coil on the side of the face opposite the magnetic recording medium so as to be wider than any other part of the conductor coil, and the step of thereafter machining the face opposite the magnetic recording medium so as to expose the outermost turn of the conductor coil on the face opposite the magnetic recording medium.

Abstract: A perpendicular magnetic recording and reproducing thin film head of a structure excellent in magnetic characteristics and easy of fabrication, wherein a lower magnetic layer disposed on a flat nonmagnetic substrate is used as a main magnetic pole, a first insulator layer is formed on the main magnetic pole, a conductor for a coil and a second insulator layer are disposed on the first insulator layer, and an upper magnetic layer which lies in contact with the lower magnetic layer through the first insulator layer at one end thereof and directly at the other end thereof and which overlies the second insulator layer in a part thereof other than both the ends is disposed and used as an auxiliary magnetic pole.

Abstract: A magnetic recording and reproducing system comprising (i) a magnetic head including a first magnetic pole whose saturation flux density is at least 7 kG and whose edge face is 0.15-0.5 .mu.m thick, and a second magnetic pole which lies on the same side as the first magnetic pole with respect to a recording medium and whose edge face is at least 10 times thicker than that of the first magnetic pole, and (ii) the perpendicular magnetic recording medium including a perpendicular magnetization layer which has a coercive force of 250-600 Oe. in a direction perpendicular to a plane thereof and which is 0.1-0.5 .mu.m thick.

Abstract: A magnetic recording and reproducing apparatus comprises a magnetic head having magnetic cores in which at least portions thereof in the vicinity of a gap are made of M.sub.n -Z.sub.n ferrite single crystal and planes of the magnetic cores forming a principal magnetic circuit are formed by {110} planes of the ferrite and <100> directions contained in the {110} planes are inclined to a surface facing a magnetic recording medium, and means for relatively moving the magnetic recording medium in an opposite and parallel direction to a projection vector on said surface facing said recording medium, of a vector directed from a site far from the surface facing the magnetic recording medium to a site near said surface in the <100> direction projected on the surface facing the magnetic recording medium. The present magnetic recording and reproducing apparatus exhibits both high wear resistance and excellent read/write characteristic.

Abstract: A magnetic head having a magnetic core formed by facing a pair of magnetic substances through a working gap at a head section confronting a magnetic recording medium is disclosed in which at least one of the magnetic substances has magnetic anisotropy, and an angle .alpha. (in a C-shaped core half) and/or an angle .alpha.' (in an I-shaped core half) between a core surface confronting the magnetic recording medium and a direction having a maximum magnetic permeability in a main magnetic circuit plane of the magnetic substance having magnetic anisotropy is made larger than an orientation angle of the above direction for making minimum the magnetic reluctance of the main magnetic circuit of the magnetic core by .beta. (for .alpha.) and/or .beta.' (for .alpha.') to improve the recording/reproducing characteristic of the magnetic head, where .beta. is given by a formula ##EQU1## is equal to or less than 25.degree.

Abstract: In a magnetic head a single-crystal Mn--Zn ferrite is employed as a core material, and cut-away parts in the vicinities of a gap are filled with a glass the contraction rate of which is lower than that of the ferrite. A principal magnetic circuit-forming plane of the core is brought into agreement with the {1 1 0} plane of the ferrite, while an angle .theta. defined between the <1 0 0> direction within the {1 1 0} plane of the ferrite and a gap forming plane is made 5.degree.-40.degree. or 80.degree.-120.degree.. The magnetic head thus constructed exhibits very favorable write and read characteristics.

Abstract: A gas sensor comprising as a gas sensible material a spinel-type ferrite represented by the general formula AFe.sub.2 O.sub.4 in which A stands for at least one member selected from the group consisting of Li, Mg, Mn, Fe, Co, Ni, Cu, Zn and Pb is provided. In many cases, a catalyzer or a recovering agent need not be incorporated in this gas sensor, and it is characterized in that it is hardly influenced by moisture in the atmosphere.

Abstract: The temperature for preparation of garnet phase of the conventional yttrium or rare-earth iron garnet can be lowered by about several hundreds centigrade by substituting 24C site of the garnet by lead. Thus obtained lead-substituted yttrium or rare-earth iron garnet has greater specific Faraday rotation than lead-nonsubstituted yttrium or rare-earth iron garnet.