Abstract: Certain example embodiments relate to a manufacturing method for a disk drive unit. At least one head gimbal assembly having first terminal pads is provided. A controlling circuit for controlling the at least one head gimbal assembly is provided, with the controlling circuit having second terminal pads to connect with the first terminal pads. The at least one head gimbal assembly is disposed in a motor base. The controlling circuit is disposed in the motor base. The at least one head gimbal assembly and the controlling circuit are tightened to the motor base such that the first and second terminal pads are face-to-face and have an electrical touch contact therebetween.

Abstract: A method of manufacturing for providing closer head-to-media spacing, and the resulting disk, includes evenly lubricating a magnetic media disk, increasing the viscosity of a selected non-data zone region of the disk, and removing at least a portion of the lower viscosity region of the lubrication layer in a data zone region of the disk, thereby decreasing the thickness of the lubrication layer in the data zone portion of the lower viscosity region, producing a magnetic media disk capable of closer head-to-media spacing in the data zone portion of the lower viscosity region of the lubrication layer than in the non-data zone portion.

Abstract: An apparatus capable of producing a moveable magnetic field includes a moveable support structure (110) and a magnetic field source (120) supported by the moveable support structure, where the magnetic field source is in a fixed position relative to the moveable support structure. The magnetic field source generates a magnetic field at a wafer surface of at least approximately 50 Oersted, and the magnetic field is aligned so as to produce magnetic anisotropy in a plane of the moveable support structure.

Abstract: Provided are a method of producing a magnetic recording medium with improved environmental resistance, especially, corrosion resistance and an apparatus used therefor.

Abstract: A high yield in a manufacture of an HDD having a high recording density and using a patterned medium by a trench-like or a dot-like pattern is realized. In this HDD manufacturing method, a magnetic field size (writing and reading) of a head in a head manufacturing process is measured in a head unit inspection process. According to the result of the measurement, the head is classified into a plurality of groups in a head classifying process. In a patterned medium manufacturing process, a plurality of types of the patterned media which are designed so as to correspond to the classified head groups are manufactured. In an HDD assembly process, the HDD is manufactured by combining the plurality of head groups and the plurality of patterned media following a predetermined rule.

Abstract: The present invention provides a ferromagnetic/antiferromagnetic coupling film structure and a fabrication method thereof. The structure includes an antiferromagnetic layer of cobalt oxide having a thickness of 2 to 15 monolayers and formed on a substrate at a temperature ranging from 700K to 900K; and a ferromagnetic layer of cobalt having a thickness of at least one monolayer for being formed on the antiferromagnetic layer of cobalt oxide.

Abstract: A method for manufacturing a magnetic field detecting element having a free layer whose magnetization direction is variable depending on an external magnetic field and a pinned layer whose magnetization direction is fixed and these are stacked with an electrically conductive, nonmagnetic spacer layer sandwiched therebetween, wherein sense current flows in a direction perpendicular to film planes of the magnetic field detecting element. The method comprises: forming a spacer adjoining layer adjacent to the spacer layer, Heusler alloy layer, and a metal layer successively in this order; and forming either at least a part of the pinned layer or the free layer by heating the spacer adjoining layer, the Heusler alloy layer, and the metal layer. The spacer adjoining layer has a layer chiefly made of cobalt and iron. The Heusler alloy layer includes metal which is silver, gold, copper, palladium, or platinum, or an alloy thereof. The metal layer is made of the same.

Abstract: A process is described for the fabrication of a magnetic read head in which contact between the pinned layer and the AFM is limited to their edges. The principal steps are to deposit an antiferromagnetic layer and to then pattern it into a pair of antiferromagnetic layers separated by no more than about 2 microns. A layer of magnetic material that lies between, and is in contact with, said antiferromagnetic layers is then deposited, following which the layer of magnetic material is magnetized.

Abstract: Magnetic materials and uses thereof are provided. In one aspect, a magnetic film is provided. The magnetic film comprises superparamagnetic particles on at least one surface thereof. The magnetic film may be patterned and may comprise a ferromagnetic material. The superparamagnetic particles may be coated with a non-magnetic polymer and/or embedded in a non-magnetic host material. The magnetic film may have increased damping and/or decreased coercivity.

Abstract: An apparatus for manufacturing a magnetic recording medium is provided. The apparatus has a plurality of connected film forming chambers; a carrier for holding a substrate; a mechanism for placing the substrate on the carrier prior to forming a film; a mechanism for sequentially transferring the carriers into the connected film forming chambers; and a mechanism for removing the substrate from the carrier after the film is formed. The mechanism for transferring the carrier is a linear motor. Furthermore, a method for manufacturing the magnetic recording medium by using such apparatus is also provided.

Abstract: A method for manufacturing a magnetic recording medium with high reliability is provided, which can form a thin magnetic layer having a dry film thickness of, for example, 60 nm or less while the occurrence of defects on the surface is suppressed. In this method, a magnetic paint having a solid concentration NV (mass %) of 3?NV?8 is applied to a non-magnetic underlayer formed over a non-magnetic support to a wet film thickness Tw in a range of ?2300 (nm).

Abstract: Magnetic recording media having a magnetic layer with an easy magnetization axis lying about 35° out of plane of the magnetic layer is disclosed. This media has a reduced total magnetic layer thickness and higher signal, while improving the media signal-to-noise ratio (SNR).

Abstract: A magnetic sensor includes a single substrate, a conventional GMR element formed of a spin-valve film including a single-layer-pinned fixed magnetization layer, and a SAF element formed of a synthetic spin-valve film including a plural-layer-pinned fixed magnetization layer. When the spin-valve film intended to act as the conventional GMR element and the synthetic spin-valve film intended to act as the SAF element are subjected to the application of a magnetic field oriented in a single direction at a high temperature, they become giant magnetoresistive elements whose magnetic-field-detecting directions are antiparallel to each other. Since films intended to act as the conventional GMR element and the SAF element can be disposed close to each other, the magnetic sensor which has giant magnetoresistive elements whose magnetic-field-detecting directions are antiparallel to each other can be small.

Abstract: A glass substrate for a magnetic disk, wherein, in regions with respect to two places arbitrarily selected on a surface of the glass substrate on its central portion side relative to its outer peripheral end, a surface shape with a shape wavelength in a band of 60 to 500 ?m is extracted from surface shapes in each of the regions and, assuming that a root mean square roughness Rq of the surface shape is given as a microwaviness Rq, the difference between the microwavinesses Rq of the regions is 0.02 nm or less or the difference between standard deviations of the microwavinesses Rq of the regions is 0.04 nm or less.

Abstract: A magnetic tunneling element is constructed from a MgO or Mg—ZnO tunnel barrier and an amorphous magnetic layer in proximity with the tunnel barrier. The amorphous magnetic layer includes Co and at least one additional element selected to make the layer amorphous. Magnetic tunnel junctions formed from the amorphous magnetic layer, the tunnel barrier, and an additional ferromagnetic layer have tunneling magnetoresistance values of up to 200% or more.

Abstract: An aspect of the present invention relates to a method of manufacturing a hexagonal ferrite magnetic powder comprising preparing a melt by melting a starting material mixture comprising a hexagonal ferrite-forming component and a glass-forming component; rapidly cooling the melt to obtain an amorphous material comprising 0.3 to 2.0 weight percent of carbon atoms; heating the amorphous material to a temperature range of 580 to 700° C. and maintaining the amorphous material within the temperature range to precipitate hexagonal ferrite magnetic particles; and collecting the hexagonal ferrite magnetic particles precipitated.

Abstract: A method of forming a plating film capable of improving magnetic properties is provided. A photoresist pattern, having a first opening with an aspect ratio greater than 1 and a second opening with an aspect ratio smaller than that of the first opening, is formed on a surface of a substrate. A seed film is formed to cover an exposed surface of the substrate in the openings and an inner wall of the photoresist pattern in the openings. On the seed film in the openings, the plating film of magnetic material is deposited such that the first opening is filled under application of a magnetic field in the direction intersecting the surface of the substrate, and the second opening is filled under application of the magnetic field in the direction along the surface of the substrate.

Abstract: A wear-resistant article of manufacture, such as a screen, is produced by the method of providing a screen having a front face, a rear face, and openings extending through the screen from the front face to the rear face, contacting at least a portion of the screen with a coating material comprising ferromagnetic or paramagnetic hard particles and a braze material, subjecting at least a portion of the screen to a magnetic field during at least a portion of the contacting step, and transforming the coating material to a wear-resistant coating comprising the hard particles distributed in the braze material.

Abstract: A method of forming a nanowire comprising: providing nanoparticles of a metallic material; providing a vapor of fluorocarbon molecules by heating a solid polymer; depositing at least some of the carbon of said molecules onto an exterior of one of said particles to form a deposit of carbon which surrounds at least part of the exterior of said one particle and assembling further of said particles with said one particle to form an elongate configuration of material in the form of a nanowire. Similar methods of production of nanotubes are also disclosed.

Abstract: NG surface information obtained in a defect inspecting step of a magnetic disk substrate is depicted on the magnetic disc substrate, so that the information can be discriminated at a succeeding film depositing step.

Abstract: A method is provided for manufacturing a magneto-resistive device. The magneto-resistive device is for reducing the deterioration in the characteristics of the device due to annealing. The magneto-resistive device has a magneto-resistive layer formed on one surface side of a base, and an insulating layer formed of two layers and deposited around the magneto-resistive layer. The layer of the insulating layer closest to the base is made of a metal or semiconductor oxide. This layer extends over end faces of a plurality of layers made of different materials from one another, which make up the magneto-resistive device, and is in contact with the end faces of the plurality of layers with the same materials.

Abstract: There is provided a method for manufacturing a magnetoresistive element having a magnetization pinned layer, a magnetization free layer, and a spacer layer including an insulating layer arranged between the magnetization pinned layer and the magnetization free layer and current paths passing through the insulating layer. The method includes, in producing the spacer layer, depositing a first non-magnetic metal layer forming the current paths, depositing a second metal layer to be converted into the insulating layer on the first non-magnetic metal layer, and performing two stages of oxidation treatments in which a partial pressure of an oxidizing gas in a first oxidation treatment is set to 1/10 or less of a partial pressure of an oxidizing gas in a second oxidation treatment, and the second metal layer being irradiated with an ion beam or a RF plasma of a rare gas in the first oxidation treatment.

Abstract: A method for producing a mold having a fine groove-ridge pattern on the surface thereof is disclosed. The method includes: a release layer forming step of forming, on a surface of a Si original plate having a groove-ridge pattern, a release layer made of a metal film containing a metal having an ionization tendency lower than that of hydrogen (for example, at least one metal selected from the group consisting of Pt, Os, Ir, Au, Ru and Pd); an electroforming step of electroforming, after the release layer has been formed, a metal substrate forming a mold; and a releasing step of releasing a duplicated plate including the release layer and the metal substrate from the Si original plate after the electroforming step.

Abstract: The present invention relates to ferromagnetic materials based on nano-sized bacterial cellulose templates. More specifically, the present invention provides an agglomerate free magnetic nanoparticle cellulose material and a method of forming such magnetic nanoparticle cellulose material. Further, the magnetic nonoparticles are physically attached on the cellulose material and evenly distribute.

Abstract: An information storage medium with an array of laterally magnetised dots, as well as a process for producing this medium is disclosed. Each dot (2) contains at least one magnetic domain formed by a thin layer (4) of at least a magnetic material laterally covering this flat material and deposited at oblique incidence relative to the normal (z) to the plane (6) of the array. The invention applies in particular to computer hard drives.

Abstract: This invention relates to a magnetic composite powder, a method of preparing the same and an electromagnetic noise suppressing film comprising the same. The magnetic composite powder and the electromagnetic noise suppressing film can effectively suppress unwanted electromagnetic waves emitted by various parts of an advanced digital device having high performance characteristics in terms of speed, frequency and functionality.

Abstract: A method for preparing a protective layer (38) on a surface of the substrate (36) that requires a bonding temperature (BT) above a detrimental phase transformation temperature range (28) of the substrate, and then cooling the layer and substrate without cracking the layer or detrimentally transforming the substrate. The protective layer (38) and the substrate (36) are cooled from the bonding temperature (BT) to a temperature (46) above the detrimental phase transformation range (28) at a first cooling rate (30) slow enough to avoid cracking the protective layer. Next, the protective layer and the substrate are cooled to a temperature below the detrimental phase transformation range of the substrate at a second cooling rate (27) fast enough to pass the detrimental phase transformation range before a substantial transformation of the substrate into the detrimental phase can occur.

Abstract: The present invention is to provide an electromagnetic wave shielding material which comprises a transparent substrate and a fine line pattern formed thereon, wherein the fine line pattern comprises a metal plating film using a physically developed metal silver as a catalytic nucleus and a process for preparing an electromagnetic wave shielding material which comprises exposing a light-sensitive material having a physical development nuclei layer and a silver halide emulsion layer on a transparent substrate in this order, precipitating metal silver with an optional fine line pattern onto the physical development nuclei layer by physical development, then, removing a layer provided on the physical development nuclei layer, and subjecting to plating a metal with the use of the physically developed metal silver as a catalytic nucleus.

Abstract: A production process of magnetic recording media is provided in which, when using an oxide magnetic material as a perpendicular magnetic recording layer and forming a carbon protective layer using a plasma CVD method, stripping of the carbon protective layer and separation of a lubrication layer can be prevented, and satisfactory recording and reproduction characteristics can be obtained.

Abstract: In one aspect, a method of nanolithography is provided, the method comprising providing a substrate; providing a scanning probe microscope tip; coating the tip with a deposition compound; and subjecting said coated tip to a driving force to deliver said deposition compound to said substrate so as to produce a desired pattern. Another aspect of the invention provides a tip for use in nanolithography having an internal cavity and an aperture restricting movement of a deposition compound from the tip to the substrate. The rate and extent of movement of the deposition compound through the aperture is controlled by a driving force.

Abstract: Disclosed is a perpendicular magnetic recording medium on a substrate. The perpendicular magnetic recording medium has a recording layer. The recording layer includes a first granular recording layer and a second granular recording layer. There may be an exchange layer between the first granular recording layer and the second granular recording layer. Additionally or alternatively, the ratio of saturation magnetization of the first granular recording layer and the second granular recording layer may be greater than 1 and/or the first granular recording layer may have a relatively high magnetic anisotropy compared to the second granular recording layer magnetic anisotropy. A forming method is also disclosed.

Abstract: In an MR element, each of a pinned layer and a free layer includes a Heusler alloy layer. The Heusler alloy layer has two surfaces that are quadrilateral in shape and face toward opposite directions. The Heusler alloy layer includes one crystal grain that touches four sides of one of the two surfaces. In a method of manufacturing the MR element, a layered film to be the MR element is formed and patterned, and then heat treatment is performed on the layered film patterned, so that crystal grains included in a film to be the Heusler alloy layer in the layered film grow and one crystal grain that touches four sides of one of the surfaces of the film to be the Heusler alloy layer is thereby formed.

Abstract: A magnetic disk apparatus having a highly sensitive reproducing head and a method for manufacturing the magnetic disk apparatus are disclosed. A spin-value-type multilayer film composed of an antiferromagnetic layer, a ferromagnetic layer, a nonmagnetic layer and a free magnetic layer is used as a magnoresistive-effect device for the reproducing head. An antiferromagnetic reaction layer is formed between the antiferromagnetic layer and the ferromagnetic layer. The antiferromagnetic reaction layer is formed of a metallic compound containing oxygen.

Abstract: Microspheres, populations of microspheres, and methods for forming microspheres are provided. One microsphere configured to exhibit fluorescent and magnetic properties includes a core microsphere and a magnetic material coupled to a surface of the core microsphere. About 50% or less of the surface of the core microsphere is covered by the magnetic material. The microsphere also includes a polymer layer surrounding the magnetic material and the core microsphere. One population of microspheres configured to exhibit fluorescent and magnetic properties includes two or more subsets of microspheres. The two or more subsets of microspheres are configured to exhibit different fluorescent and/or magnetic properties. Individual microspheres in the two or more subsets are configured as described above.

Abstract: The invention discloses a device and a method for transferring a predeterminable, high-resolution magnetic design onto a document printed with a magnetic ink, in particular a magnetic optically variable ink. The device comprises a body of a composite permanent-magnetic material, having at least one flat or curved surface engraved with indicia corresponding to the design to be transferred, wherein the said magnetic material is permanently magnetized, preferably in a direction substantially perpendicular to the said surface. The method comprises imprinting or coating a first surface of a sheet or web with a magnetic ink or coating composition, and approaching the imprinted sheet or web to the engraved surface of a body of magnetized composite permanent-magnetic material while the ink is wet, followed by hardening the ink.

Abstract: Servo patterns and associated methods of fabricating servo patterns are described. For patterned storage media, data sectors and servo sectors may be patterned using self-assembly. In one embodiment, self-assembly is used to form a first array of islands and a second array of islands in servo sectors that are track-wise offset. A servo writing process is then performed to write a desired servo pattern in the arrays, such as for burst fields, synchronization fields, etc.

Abstract: Provided is a magnetic recording medium substrate suitable for preparation of a DT medium and a patterned medium, and the magnetic recording medium substrate is possible to be of easy preparation of the DT medium and the patterned medium with no complicated processes. Disclosed is a magnetic recording medium substrate comprising a circular plate-shaped substrate made of a nonmagnetic base material, wherein a predetermined region of a surface of the substrate to form a magnetic film on the surface is more roughened than another region of the surface. When forming a magnetic film on this substrate, the magnetic film is formed in the region of the substrate surface, which is more roughened than the other region, to easily prepare the DT medium and the patterned medium.

Abstract: The invention includes devices and methods for forming random arrays of magnetic particles, arrays formed using these devices and methods, and to methods of using the arrays. The invention provides an assembly (chip) with magnetic domains that produce localized magnetic fields capable of immobilizing magnetic particles such as commercially available magnetic beads. Probe or sensor molecules can be coupled to the beads, which are then dispersed on the assembly, forming a random order array. The arrays can be used for analyzing samples, targets, and/or the interaction between samples and targets. The invention finds particular use in processes such as high-throughput genotyping and other nucleic acid hybridization-based assays.

Abstract: An aspect of the present invention relates to a magnetic recording medium comprising a magnetic layer on a nonmagnetic organic material support, wherein the magnetic layer comprises a magnetic material comprising a hard magnetic material comprising a rare earth element, and on a portion of a surface of the hard magnetic material, a soft magnetic region, and the soft magnetic region is exchange-coupled with the hard magnetic material. Another aspect of the present invention relates to a method of manufacturing a magnetic recording medium comprising forming a hard magnetic layer by coating a coating liquid comprising a hard magnetic material comprising a rare earth element on a nonmagnetic organic material support, and forming, on at least a portion of a surface of the hard magnetic material comprised in the hard magnetic layer, a soft magnetic region, the soft magnetic region being exchange-coupled with the hard magnetic material.

Abstract: Apparatuses, methods and systems for applying a coating to an ear of corn in a high throughput manner are disclosed. The system includes means for moving the ear of corn through the system and means for coating the ear of corn with a coating while passing through the system. The apparatus includes a carrying position for an ear of corn, an automated line having a plurality of the carrying positions, and an automated coating station adapted to apply a coating to the ear of corn on the automated line. The method includes staging a plurality of ears of corn on an automated line, passing the automated line through an ear coating process, and coating the plurality of ears of corn with a coating.

Abstract: An aspect of the present invention relates to a method of manufacturing a hexagonal ferrite magnetic powder comprising preparing a melt by melting a starting material mixture, wherein the starting material mixture comprises at least one hexagonal ferrite-forming component and glass-forming component comprising at least one B2O3 component and a content of the B2O3 component in the mixture ranges from 15 to 27 mole percent in terms of B2O3; rapidly cooling the melt to obtain a solid having a saturation magnetization level of equal to or lower than 0.6 A·m2/kg; and heating the solid to a temperature range of 600 to 690° C. and maintaining the solid within the temperature range to precipitate a hexagonal ferrite magnetic powder having an average plate diameter ranging from 15 to 25 nm.

Abstract: A magnetic recording medium, a manufacturing method thereof, and a magnetic recording/reproducing apparatus are provided, capable, with a configuration having a magnetic recording film only on one side, of suppressing warp occurrence, and obtaining a high quality and thin-type magnetic recording medium. When forming a recording layer having at least a magnetic recording film on one main surface of a substrate by means of a vapor-phase film forming method, a thin film is formed on the other main surface of the substrate using a vapor-phase film forming method. When the recording layer is formed as a multiple layer structure, the thin film is also formed as a multiple layer structure with the same number of laminations as for the recording layer 5, and layer pairs of the same lamination order as the recording layer and the thin film are preferably formed concurrently in the same chamber.

Abstract: The invention relates to a perpendicular magnetic recording medium comprising a substrate and a granular magnetic layer comprising ruthenium or ruthenium oxide in the grain boundaries.

Abstract: Provided are a magnetic recording medium substrate whereupon a magnetic layer can be regularly formed in a recording area, a magnetic recording medium and a method for manufacturing the magnetic recording medium substrate. A plurality of recording areas wherein the magnetic layer is to be formed are formed on the surface of the disk-shaped magnetic recording medium substrate. The size of the recording area is an integral multiple of a lattice constant of a unit lattice of a single crystal structure constituting the magnetic layer. For instance, the width of a protruding section (3) to be used as the recording area is an integral multiple of the lattice constant of the unit lattice of the single crystal structure configuring the magnetic layer.

Abstract: There are provided a composite magnetic body exhibiting a sufficiently low magnetic loss at frequencies of several hundreds of megahertz to several gigahertz, and a method of manufacturing the same. The composite magnetic body contains a magnetic powder dispersed in an insulating material. The magnetic powder is in a spherical shape or an elliptic shape. The composite magnetic body has any one of the following characteristics (a) to (c): (a) the relative magnetic permeability ?r is larger than 1 and the loss tangent tan ? is 0.1 or less, at a frequency of 1 GHz or 500 MHz; (b) the real part ?r? of the complex permeability is more than 10 and the loss tangent tan ? is 0.3 or less, at a frequency of 1.2 GHz or less; and (c) the real part ?r? of the complex permeability is more than 1 at a frequency of 4 GHz or less, and the loss tangent tan ? is 0.1 or less at a frequency of 1 GHz or less.

Abstract: A perpendicular magnetic recording medium is manufactured having excellent thermal stability and recording performances across the entire disk surface. In one embodiment, the recording layer includes at least two layers deposited by using a reactive sputtering method under an oxygen-containing atmosphere at a deposition rate larger than the second recording layer which is formed on the first recording layer while depositing the first recording layer on the intermediate layer.

Abstract: An in-line film forming apparatus capable of conveying a carrier at a high speed, increasing the exhaust capability within a film forming chamber, and easily realizing a high vacuum degree in a short time is provided. A conveyor mechanism has a linear motor drive mechanism which drives the carrier in a noncontact state, a horizontal guide mechanism which is provided so as to be able to contact a side portion of the carrier, and guides the carrier driven by the linear motor drive mechanism in a horizontal direction, and a vertical guide mechanism which is provided so as to be able to contact a lower end of the carrier, and guides the carrier driven by the linear motor drive mechanism in the vertical direction.

Abstract: An electromagnetic noise suppressor of the present invention includes a base material containing a binding agent and a composite layer formed by integrating the binding agent that is a part of the base material and the magnetic material. This electromagnetic noise suppressor has high electromagnetic noise suppressing effect in the sub-microwave band, and enables it to reduce the space requirement and weight. The electromagnetic noise suppressor can be manufactured by forming the composite layer on the surface of the base material by physical vapor deposition of the magnetic material onto the surface of the base material. The article with an electromagnetic noise suppressing function of the present invention is an electronic component, a printed wiring board, a semiconductor integrated circuit or other article of which at least a part of the surface is covered by the electromagnetic noise suppressor of the present invention.

Abstract: A perpendicular magnetic recording medium and method thereof, includes a nonmagnetic substrate; a soft magnetic under layer; an intermediate layer; a bilayer magnetic recording layer; a protective layer; and a liquid lubricant layer. According to a following order, the soft magnetic under layer, the intermediate layer, the bilayer magnetic recording layer, the protective layer, and the liquid lubricant layer are sequentially stacked on the nonmagnetic substrate. The bilayer magnetic recording layer includes a first magnetic layer including a CoCr alloy crystalline film, and a second magnetic layer including a rare earth-transition metal alloy noncrystalline film.

Abstract: The present invention provides a method of manufacturing a magnetic recording medium that is made by applying a magnetic paint containing a ferromagnetic powder and a binder to a nonmagnetic support, wherein the magnetic paint contains a magnetic liquid, which contains the ferromagnetic powder and the binder, and a polishing material liquid, which contains a polishing material and a solvent, and wherein the magnetic liquid and the polishing material liquid are individually subjected to dispersion treatment, the magnetic liquid and the polishing material liquid are then mixed together, and after that, a mixed liquid of the magnetic liquid and the polishing material liquid are subjected to dispersion treatment by application of ultrasonic waves.