Abstract: Nucleoside 5?-phosphate ester is produced by culturing a bacterium belonging to the genus Escherichia having an ability to produce nucleoside 5?-phosphate ester, in which ushA gene and aphA gene do not function normally, in a medium to produce and accumulate nucleoside 5?-phosphate ester in the medium, and collecting the nucleoside 5?-phosphate ester from the medium.

Abstract: The present invention provides an insulation characteristic measuring method of measuring electrical insulation of magnetic head elements formed on a wafer. Each of the magnetic head elements includes an upper magnetic pole layer, a lower magnetic pole layer, insulation layers disposed between the upper and lower magnetic pole layers, and a coil layer formed of a conductive material and disposed between the insulation layers. In at least one of the magnetic head elements, the upper and lower magnetic pole layers are electrically insulated from each other, and the upper and lower magnetic pole layers and the coil layer of the element are respectively connected to terminals of electrodes for measuring insulation. The insulation characteristic of the magnetic head elements is measured by the electrodes. It is therefore possible to measure whether insulation is ensured between layers of the magnetic head elements, which need to be insulated from each other.

Abstract: Nucleoside 5?-phosphate ester is produced by culturing a bacterium belonging to the genus Escherichia having an ability to produce nucleoside 5?-phosphate ester, in which ushA gene and aphA gene do not function normally, in a medium to produce and accumulate nucleoside 5?-phosphate ester in the medium, and collecting the nucleoside 5?-phosphate ester from the medium.

Abstract: The method of manufacturing a thin film magnetic head is capable of precisely forming a core section with preventing the variation of the write-core head caused by ion milling for removing an electric conductive film and capable of improving yield of products. The method of manufacturing a thin film magnetic head, in which a core section having prescribed write-core width is formed by applying ion milling to an upper magnetic pole and a lower magnetic pole, comprises the steps of examining the write-core width of the core section; covering a surface of the core section with a protection film except an electric conductive film for preventing electro static charge of a wafer; and removing the exposed electric conductive film by ion milling.

Abstract: An object of the present invention is to provide a recording head having a magnetic pole simultaneously possessing a high saturation magnetic flux density, a high permeability and a high electric resistivity, and the magnetic pole of the recording head is a polycrystalline film comprising Fe whose content is not less than 57.5 atomic % and not more than 94.5 atomic %; one or more kinds of elements selected from the element group of Al, B, Ga, Si, Ge, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and Rh, whose whole content is not less than 1 atomic % and not more than 15 atomic %; N whose content is not less than 0.5 atomic % and not more than 10 atomic %; and O whose content is not less than 1.5 atomic % and not more than 22.5 atomic %.

Abstract: A liquid resist is introduced between adjacent conductive lines of a coil pattern girdling around a magnetic core piece. When the liquid resist is cured, an insulating resin filler can be fixed between the adjacent conductive lines of the coil pattern. An insulating metallic layer is formed to extend over the insulting resin filler and the conductive lines of the coil pattern. Thereafter, the insulating metallic layer is subjected to a flattening grinding treatment until at least a part of the conductive line is exposed at a flattened surface. Of the resist, of a higher fluidity, penetrates in every hole and corner between the adjacent conductive lines, the gap defined between the adjacent conductive lines is fully filled with the insulating material. No voids remain in the gap. The conductive line of the coil can be reliably prevented from corrosion or oxidation. Moreover, a relatively brittle of fragile insulating resin filler is reliably prevented from being subjected to the flattening.

Abstract: Nucleoside 5′-phosphate ester is produced by culturing a bacterium belonging to the genus Escherichia having an ability to produce nucleoside 5′-phosphate ester, in which ushA gene and aphA gene do not function normally, in a medium to produce and accumulate nucleoside 5′-phosphate ester in the medium, and collecting the nucleoside 5′-phosphate ester from the medium.

Abstract: A thin film magnetic head includes an upper and a lower magnetic pole layer extending forward from a central magnetic core within a thin film coil. A narrow upper and lower front magnetic pole piece are connected to the front ends of the upper and lower magnetic pole layer, respectively. The upper front magnetic pole piece extends rearward from its front end exposed at a medium-opposed surface. The lower front magnetic pole piece extends in a lateral direction along the medium-opposed surface by a lateral width larger than that of the upper front magnetic pole piece. The lower front magnetic pole piece extends rearward from the medium-opposed surface by a longitudinal length smaller than that of the upper front magnetic pole piece. The lower front magnetic pole piece serves to concentrate the magnetic flux at the front ends of the upper and lower front magnetic pole pieces.

Abstract: The method of manufacturing a thin film magnetic head is capable of precisely forming a core section with preventing the variation of the write-core head caused by ion milling for removing an electric conductive film and capable of improving yield of products. The method of manufacturing a thin film magnetic head, in which a core section having prescribed write-core width is formed by applying ion milling to an upper magnetic pole and a lower magnetic pole, comprises the steps of examining the write-core width of the core section; covering a surface of the core section with a protection film except an electric conductive film for preventing electro static charge of a wafer; and removing the exposed electric conductive film by ion milling.

Abstract: An upper auxiliary magnetic pole is formed in a space on a lower magnetic pole layer. A first insulating layer is then formed over the surface of the lower magnetic pole layer. The upper auxiliary magnetic pole is embedded within a swell formed on the surface of the first insulating layer. A second insulating layer is then formed over the surface of the first insulating layer. The second insulating layer has a property less abrasive than the first insulating layer. The second insulating layer is subjected to grinding over a wider area just after the swell has completely been removed. The abrasion can be suppressed at the thin film magnetic head in which the swell has been removed. The first insulating layer of a predetermined thickness reliably remains in each of the thin film magnetic heads on the wafer. An accurate adjustment of the thickness of the first insulating layer leads to a reliable establishment of a predetermined thickness in the upper auxiliary magnetic pole with less error.

Abstract: A liquid resist is introduced between adjacent conductive lines of a coil pattern girdling around a magnetic core piece. When the liquid resist is cured, an insulating resin filler can be fixed between the adjacent conductive lines of the coil pattern. An insulating metallic layer is formed to extend over the insulting resin filler and the conductive lines of the coil pattern. Thereafter, the insulating metallic layer is subjected to a flattening grinding treatment until at least a part of the conductive line is exposed at a flattened surface. Since the liquid of the resist, of a higher fluidity, penetrates in every hole and corner between the adjacent conductive lines, the gap defined between the adjacent conductive lines is fully filled with the insulating material. No voids remain in the gap. The conductive line of the coil can be reliably prevented from corrosion or oxidation.

Abstract: A liquid resist is introduced between adjacent conductive lines of a coil pattern girdling around a magnetic core piece. When the liquid resist is cured, an insulating resin filler can be fixed between the adjacent conductive lines of the coil pattern. An insulating metallic layer is formed to extend over the insulting resin filler and the conductive lines of the coil pattern. Thereafter, the insulating metallic layer is subjected to a flattening grinding treatment until at least a part of the conductive line is exposed at a flattened surface. Since the liquid of the resist, of a higher fluidity, penetrates in every hole and corner between the adjacent conductive lines, the gap defined between the adjacent conductive lines is fully filled with the insulating material. No voids remain in the gap. The conductive line of the coil can be reliably prevented from corrosion or oxidation.

Abstract: An object of the present invention is to provide a recording head having a magnetic pole simultaneously possessing a high saturation magnetic flux density, a high permeability and a high electric resistivity, and the magnetic pole of the recording head is a polycrystalline film comprising Fe whose content is not less than 57.5 atomic % and not more than 94.5 atomic %; one or more kinds of elements selected from the element group of Al, B, Ga, Si, Ge, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and Rh, whose whole content is not less than 1 atomic % and not more than 15 atomic %; N whose content is not less than 0.5 atomic % and not more than 10 atomic %; and O whose content is not less than 1.5 atomic % and not more than 22.5 atomic %.

Abstract: Nucleoside 5′-phosphate ester is produced by culturing a bacterium belonging to the genus Escherichia having an ability to produce nucleoside 5′-phosphate ester, in which ushA gene and aphA gene do not function normally, in a medium to produce and accumulate nucleoside 5′-phosphate ester in the medium, and collecting the nucleoside 5′-phosphate ester from the medium.

Abstract: An upper auxiliary magnetic pole is formed in a space on a lower magnetic pole layer. A first insulating layer is then formed over the surface of the lower magnetic pole layer. The upper auxiliary magnetic pole is embedded within a swell formed on the surface of the first insulating layer. A second insulating layer is then formed over the surface of the first insulating layer. The second insulating layer has a property less abrasive than the first insulating layer. The second insulating layer is subjected to grinding over a wider area just after the swell has completely been removed. The abrasion can be suppressed at the thin film magnetic head in which the swell has been removed. The first insulating layer of a predetermined thickness reliably remains in each of the thin film magnetic heads on the wafer. An accurate adjustment of the thickness of the first insulating layer leads to a reliable establishment of a predetermined thickness in the upper auxiliary magnetic pole with less error.

Abstract: A MR head employs a biasing soft magnetic film of a FeXN-based alloy which undergoes no change in the direction of its axis of easy magnetization even when subject to heat treatment. The MR head has an anisotropic magnetic field size of 10 Oe or greater, and electrical resistance p of 70 .mu..OMEGA.cm or greater, and a saturation flux density Bs of 1 T or greater. The direction of the axis of easy magnetization of the biasing soft magnetic film is oriented perpendicular to the direction of sense current, and the direction of the axis of easy magnetization of the MR film is oriented parallel to the sense current direction.