865 results about "Recording density" patented technology

Provided is a magnetic recording medium capable of achieving high reproduction output in a short wavelength region. The magnetic recording medium comprises a nonmagnetic layer comprising a nonmagnetic powder and a binder and a magnetic layer comprising a ferromagnetic powder and a binder in this order on a nonmagnetic support. The magnetic layer has a squareness ranging from 0.6 to 1.0 in a perpendicular direction, and the magnetic recording medium is employed for recording a magnetic signal on the medium in a longitudinal direction at a linear recording density of equal to or greater than 300 Kbpi using a recording head with a gap length of equal to or less than 0.3 micrometer, and reproducing the magnetic signal using a magnetoresistive head with a shield spacing of equal to or less than 0.2 micrometer.

Disclosed is a magnetic disk that has excellent durability, particularly excellent LUL durability, and excellent alumina resistance and has a high level of reliability under a low flying height of a magnetic head involved in a recent tendency toward a rapid increase in recording density and a very severe environment resistance requirement due to diversified applications. A magnetic disk (10) comprises a substrate (1) and at least a magnetic layer (6), a carbon-based protective layer (7), and a lubricating layer (8) provided in that order over the substrate (1). The lubricating layer (8) contains a compound that has a perfluoropolyether main chain in the structure thereof and has an aromatic group and a polar group at the end of the molecule.

It is intended to reduce the media noise, and to improve the recording density dependence of read output voltage. The present invention provides a perpendicular magnetic recording media and its manufacturing process, wherein a perpendicular magnetic recording medium comprises a soft magnetic underlayer film and a perpendicular magnetizing film, these films being formed on a substrate in this order, a smoothness control film such as Cr film, being inserted between the substrate and the soft magnetic underlayer film. Therefore, perpendicular orientation and surface smoothness are improved for the perpendicular magnetizing film laminated on the smooth surface of the soft magnetic underlayer film. As the perpendicular orientation is improved for the perpendicular magnetizing film, the initial layer is reduced, thereby media noise being lowered and recording density dependence of read output voltage being improved. In addition, as the surface smoothness is improved for the perpendicular magnetizing film, sliding characteristics of a recording/reproducing head is also improved, thereby this also lowering the media noise.

It is aimed to provide a perpendicular magnetic recording medium capable of dealing with an ultra-higher recording density than before and its manufacturing method.

The present invention concerns a perpendicular magnetic recording medium including at least a seed layer made of noncrystalline ceramic, a crystalline orientation control layer and a magnetic layer made of a material mainly containing a FePt alloy in this order on a substrate. This perpendicular magnetic recording medium is suitably manufactured by forming at least the seed layer, the orientation control layer and the magnetic layer made of the material mainly containing the FePt alloy in this order on the substrate by sputtering, wherein the magnetic layer is formed at a predetermined temperature of 500° C. or less.

An object of the present invention is to provide a perpendicular magnetic recording medium the SNR of which is improved by reducing noise thought to be due to an auxiliary recording layer so that a higher recording density can be achieved, and a method of manufacturing the same.

In order to achieve the above object, a representative configuration of a perpendicular magnetic recording medium 100 according to the present invention includes, on a base, at least a magnetic recording layer 122 having a granular structure in which a non-magnetic grain boundary portion is formed between crystal particles grown in a columnar shape; a non-magnetic split layer 124 disposed on the magnetic recording layer 122 and containing Ru and oxygen; and an auxiliary recording layer 126 that is disposed on the split layer 124 and that is magnetically approximately continuous in an in-plane direction of a main surface of the base 110.

An object of the present invention is to provide a perpendicular magnetic recording medium the SNR of which is further improved while a high coercive force Hc is secured so that a higher recoding density can be achieved.

The structure of a perpendicular magnetic recording medium 100 according to the present invention includes, on a base, at least a first magnetic recording layer 122a having a granular structure in which a non-magnetic grain boundary portion is formed between crystal particles grown in a columnar shape; a non-magnetic split layer 122b containing Ru disposed on the first magnetic layer; and a second magnetic recording layer 122c that is disposed on the split layer and that has a granular structure in which a non-magnetic grain boundary portion is formed between crystal particles grown in a columnar shape, wherein the first magnetic layer and the second magnetic layer contain oxides that form the grain boundary, and when an oxide content of the first magnetic layer is represented by A and an oxide content of the second magnetic layer is represented by B, a relationship between the oxide contents A/B is in the range of 0.5<A/B<1.0.

A magnetic disk is provided which is excellent in durability of the magnetic disk or particularly in LUL durability and CFT characteristics and has high reliability under a decreased floating amount of the magnetic head accompanying the recent rapid increase in a recording density and extremely severe environmental resistance accompanying diversification of the applications.

The magnetic disk of the present invention is a magnetic disk having at least a magnetic layer, a carbon protective layer, and a lubrication layer sequentially provided on a substrate, and the lubrication layer is a film formed by a lubricant that contains two types of compounds having a perfluoropolyether main chain in the structure, a molecular weight distribution of the two types in total being within a range of 1 to 1.2, the two types of compounds including a compound a having a hydroxyl group at the end and a compound b having a number average molecular weight smaller than the number average molecular weight of the compound a and not more than 1500, and a content of the compound b in the two types of compounds being not more than 10%.

A CPP-GMR spin value sensor structure with an improved MR ratio and increased resistance is disclosed. All layers except certain pinned layers, copper spacers, and a Ta capping layer are oxygen doped by adding a partial O₂ pressure to the Ar sputtering gas during deposition. Oxygen doped CoFe free and pinned layers are made slightly thicker to offset a small decrease in magnetic moment caused by the oxygen dopant. Incorporating oxygen in the MnPt AFM layer enhances the exchange bias strength. An insertion layer such as a nano-oxide layer is included in one or more of the free, pinned, and spacer layers to increase interfacial scattering. The thickness of all layers except the copper spacer may be increased to enhance bulk scattering. A CPP-GMR single or dual spin valve of the present invention has up to a threefold increase in resistance and a 2 to 3% increase in MR ratio.

[Problem] A perpendicular magnetic disk with an improved SNR and an increased recording density by further improving crystal orientation of a preliminary ground layer formed of an Ni-base alloy is provided.

[Solution] A typical structure of the perpendicular magnetic disk according to the present invention includes, on a base 110, a soft magnetic layer 130, a Ta alloy layer 140 provided on the soft magnetic layer 130, an Ni alloy layer 142 provided on the Ta alloy layer 140, a ground layer 150 provided on the Ni alloy layer 142 and having Ru as a main component, and a granular magnetic layer 160 provided on the ground layer 150. The Ta alloy layer 140 is a layer containing 10 atomic percent or more and 45 atomic percent or less Ta and having amorphous and soft magnetic properties.

A lubricant compound for a magnetic disk is provided which can realize further reduction of the magnetic spacing and moreover, has high reliability under a lower floating amount of the magnetic head involved with the recent rapid increase in the recording density and under extremely severe environmental resistance involved with diversification of the applications.

A lubricant compound is contained in a lubrication layer of a magnetic disk in which at least a magnetic layer, a protective layer, and a lubrication layer are sequentially provided on a substrate, and the lubricant compound contains a component A and a component B expressed by the following chemical formula:

[Chemical formula]1

Component A: X=OH

Component B: X=OCH₂CH(OH)CH₂OH

and a component C made of a specific compound having a phosphezene ring in the structure thereof.

By improving sliding durability while ensuring a high SNR, an improvement in reliability and a further increase in recording density are to be achieved.

The structure of a method of manufacturing a perpendicular magnetic recording medium according to the present invention includes: a main recording layer forming step of forming, on a substrate, at least a main recording layer formed of magnetic particles having a CoCrPt alloy as a main component and a non-magnetic grain boundary part having an oxide as a main component; a split layer forming step of forming a split layer having a Ru alloy or a Co alloy as a main component on the main recording layer; a first heating step of performing a heat treatment on the substrate after the split layer forming step; an auxiliary recording layer forming step of forming an auxiliary recording layer formed of a material having CoCrPt as a main component after the first heating step; a second heating step of performing a heat treatment on the substrate after the auxiliary recording layer forming step; and a protective layer forming step of forming a protective layer having carbon as a main component by CVD after the second heating step.

A perpendicular magnetic recording medium has a magnetic recording layer and laminated magnetic layers composed of different materials. In a first magnetic layer of the magnetic recording layer, ferromagnetic grains are surrounded by a nonmagnetic grain boundary region composed principally of oxide and/or nitride. In a second magnetic layer of the magnetic recording layer, ferromagnetic grains are surrounded by a nonmagnetic grain boundary region composed principally of chromium. The recording medium has an intermediate layer composed of a material having hcp or fcc structure. Advantageously, a heating process is conducted after forming the first magnetic layer and before forming the second magnetic layer. The medium achieves improvement in electromagnetic conversion characteristics and simultaneously improvement in corrosion resistance to provide a perpendicular magnetic recording medium with high recording density and simultaneously high reliability.

The present invention is to make it possible to form a fine pattern, and improve a recording density on a magnetic recording medium and increase signal intensity. There is provided an electron beam irradiating method which irradiates an electron beam on a resist to perform irradiating using an electron beam irradiating apparatus provided with a moving mechanism which moves a state on which a substrate applied with the resist is put in one horizontal direction, and a rotating mechanism which rotates the stage. The electron beam irradiating method includes: exposing a portion once exposed while changing a deflection amount of the electron beam at least one time in the next round and rounds subsequent thereto, when exposure is performed while a deflection amount of an electron beam is being gradually changed so as to draw a concentric circle for each round.

Embodiments of the invention achieve a decrease in electric power consumption while ensuring high recording density and high reliability in a magnetic disk apparatus. In one embodiment, a magnetic disk apparatus comprises a rotatable magnetic disk and a magnetic head slider to be able to fly above a surface of the magnetic disk. The magnetic head slider comprises an air bearing surface, by which the magnetic head slider is caused to fly and come near to the rotating surface of the magnetic disk with a predetermined spacing therebetween, recording and reproducing elements to perform at least one of recording on and reproduction from the magnetic disk, and a heating device to adjust a distance between the recording and reproducing elements and the surface of the magnetic disk. The heating device is mounted such that heating thereof causes a part of the air bearing surface to expand and project to increase a distance between the recording and reproducing elements and the surface of the magnetic disk.

A method is designed for recording contents information along a track of an optical disk of a writeable type. A volume detection step is carried out for detecting an actual volume of the contents information to be recorded into the optical disk. A capacity detection step is carried out for detecting a nominal capacity of the optical disk, which indicates a rated volume of information to be recorded at maximum. A density determination step is carried out for determining a recording density of the contents information based on the detected actual volume and the detected nominal capacity. A record step is carried out for recording the contents information into the optical disk at the determined recording density such that the actual volume of the contents information can fit into the nominal capacity of the optical disk.

The present invention provides an optical disk identification device for use in an optical disk reproduction apparatus for reproducing a plurality of types of optical disks based on information recorded on the optical disks. Recorded information is reproduced from an optical disk 1 while an optical pickup 3 is fixed at a focal position Pf. A focal position detector 32 generates a focal position detection signal Sg that is either at a high level or at a low level at the focal position Pf based on reproduced signals Sa, Sb, Sc, Sd. An RF signal detector 20 detects an RF signal Srf from the reproduced signal based on the focal position detection signal Sg. A recording density identifier 31, S14, S20 identifies the recording density of the optical disk based on the RF signal. A format identifier S16 to S24 identifies the type of the optical disk based on the detected recording density.