Abstract: A composite type magnetic head core slider including a slider body and a core chip, wherein a slot is formed in the slider body such that the slot is open in an end face of the slider body and located within a width of a central recessed portion between two parallel air-bearing portions formed on a surface of the slider body which is to face a magnetic disk, or within a width of an outer recessed portion disposed on one side of one of the air-bearing portions, which one side is remote from the central recessed portion. The core chip is fixed in the slot such that an upper end portion of the core chip protrudes above a surface of the central or outer recessed portion, and the protruding upper end portion of the core chip is subjected to an operation to form a track portion having a magnetic gap.

Abstract: A method of producing a ferrite/Sendust composite core for a magnetic head, in which a metal film made of any one of metals of Zn, Cr, Fe, Cd, Co, Ni, Sn and Pb is formed on a surface, where a track of the core is formed, of a gapped bar composed of ferrite and Sendust, before the gapped bar is subjected to a laser-induced etching in an alkali metal hydroxide aqueous solution. The metal film serves to prevent the formation of dull at an edge portion of the track, so that a magnetic core can be obatined having a track which is free from dulls and high in reliability.

Abstract: A composite core for magnetic head composed of ferrite and Sendust, in which a difference between a track width of ferrite track and a track width of Sendust track is so small can be obtained by subjecting a gapped bar composed of ferrite and Sendust to a laser-induced etching in an alkali metal hydroxide aqueous solution into which additives for generating aluminate ion in the aqueous solution.

Abstract: A core for magnetic head, which has a groove depth of at least 10 .mu.m with a dimensional accuracy not lower than .+-.2 .mu.m in the groove for defining the track of the core, can be obtained by subjecting a gapped bar made of ferrite and/or Sendust to a laser-induced etching wherein a laser beam having a focused beam diameter of not larger than 50 .mu.m, preferably not larger than 20 .mu.m, and a laser power P in a specified range is irradiated at a scanning speed V that is within a range between 2 .mu.m/sec and 200 .mu.m/sec and delimited by the laser power P, in a phosphoric acid or alkali metal hydroxide aqueous solution.

Abstract: A method of producing a magnetic head core slider including integrally formed slider body and yoke portion. The slider body has two parallel air bearing portions, while the yoke portion has a track portion. The slider body and yoke portion cooperatively provide a magnetic gap open in the track portion. The core slider is prepared from an integral ferrite bar consisting of a first and a second ferrite block which give the slider body and the yoke portion, respectively. Track-defining grooves are formed by laser-induced etching in one surface of the bar, such that the grooves extend across the interface of the bonded two blocks. The grooves define the width of the track portion. An etching mask is applied to cover portions of the bar corresponding to the air bearing portions and the track portion. The masked surface of the bar is chemically etched to form the air bearing portions, and a track protrusion including the track portion, such that the air bearing portion and the track protrusion have the same height.

Abstract: A core for magnetic head, which has a surface roughness of not higher than 2 .mu.m in the side wall of a groove for defining the track width of the core, can be obtained by subjecting at least a portion, which defines the track width, of a gapped bar made of ferrite and having a coil turn hole and a magnetic gap, to a laser-induced etching under a condition that a laser light having a power of 50-1,100 mW and a focused beam diameter of not larger than 20 .mu.m is irradiated to at least the track width-defining portion at a scanning speed of 2-110 .mu.m/sec in a halogen gas- or halide gas-containing atmosphere kept to a gas pressure of 10-200 Torr.