447results about "Base layers for recording layers" patented technology

The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape. VIVA 0.1, which is a height that is obtained by measuring a surface of the magnetic layer with an atomic force microscope and at which a cross-sectional area is 0.1% with a measurement region area as 100%, is 5 nm or more and 10 nm or less, and standard deviation σ of the VIVA 0.1 in a width direction of the surface of the magnetic layer is 1.0 nm or less.

The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape. CS VIVA 0.1, which is a height that is obtained by measuring a surface of the magnetic layer with an atomic force microscope and at which a cutout length is 0.1% with a length of one side of a measurement region as 100%, is 4 nm or more and 10 nm or less, and standard deviation a of the CS VIVA 0.1 in a width direction of the surface of the magnetic layer is 1.0 nm or less.

The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape. A core void volume Vvc specified in international organization for standardization (ISO) 25178 on a surface of the magnetic layer is 1.200 nm3 or more and 3.000 nm3 or less, and standard deviation a of the Vvc in a width direction of the surface of the magnetic layer is 0.120 nm3 or less.

To provide a magnetic tape which can contribute to increase of the operation stability of a drive in recording and / or reproduction after a long-time storage.SOLUTION: The magnetic tape has a non-magnetic supporting body and a magnetic layer including ferromagnetic powders. The present invention also provides a magnetic tape cartridge and a magnetic tape device including the magnetic tape. The height Spk of a protruding mounting part defined by ISO 25178 in the surface of the magnetic layer is at least 1.5nm and is 3.0nm at largest. The standard deviation σ of the Spk in the width direction of the surface of the magnetic layer is 0.5 nm at largest.SELECTED DRAWING: None

A main object of the present technology is to improve the reliability of a magnetic recording tape by controlling the distribution of the binder in the underlayer.The present technology provides a magnetic recording medium including a magnetic layer, an underlayer, and a base layer in this order, the underlayer containing a chlorine-containing binder, the underlayer including a part having a thickness of 130 nm or less, the part having a chlorine count equal to or more than a threshold described below:[T⁢hreshold]=[⁠an⁢ average⁢ chlorine⁢ count⁢ in⁢ the⁢ underlayer]+6×[a⁢ standard⁢ deviation⁢ determined⁢ in⁢ calculation⁢ of⁢ the⁢ average⁢ chlorine⁢ count].Furthermore, the present technology also provides a magnetic recording medium including a magnetic layer, an underlayer, and a base layer in this order, the underlayer containing a chlorine-containing binder, the underlayer including a part having a thickness of 12% or less of a thickness of the underlayer, the part having a chlorine count equal to or more than the above-described threshold.

Various apparatuses, systems, methods, and media are disclosed to provide a heat-assisted magnetic recording (HAMR) medium that includes a sacrificial layer and corresponding etching processes to minimize head to media spacing. The medium may include the sacrificial layer and a capping layer where each of the layers is etched to reduce roughness. The sacrificial layer is configured to ensure an etch rate that allows for selective etching and may be deposited on the capping layer and after etching, may remain along grain boundaries of the capping layer. The remaining portions of the sacrificial layer may form a discontinuous layer, including layer segments positioned along grain boundaries of the capping layer. The sacrificial layer may be made of non-magnetic materials different from the materials of the capping layer or materials of an overcoat layer deposited on the etched capping layer.

Provided is a magnetic recording medium with a tape shape capable of correcting a change in width of the magnetic recording medium by adjusting a running tension of the magnetic recording medium in a case where the magnetic recording medium is saved or caused to run in a high-temperature environment. The magnetic recording medium is a magnetic recording medium with a tape shape, an amount of change in average width of the magnetic recording medium before and after the magnetic recording medium is left still for 40 hours in an environment at a temperature of 50° C. and a relative humidity of 40% RH in a state where a tension of 0.55 N is applied in a longitudinal direction is 170 ppm or less, and an average tension responsiveness with respect to a tension in the longitudinal direction in the environment at a temperature of 50° C. and a relative humidity of 40% RH is 700 ppm / N or more.

The present invention relates to an aluminum alloy disk material (1) having: a peeled surface, which is obtained by peeling a base layer containing Ni from at least one recycled material of an intermediate material or finished product including an aluminum alloy disk and the base layer; and an oxide film (10) on the surface of the peeled surface.

To provide an aluminum alloy plate for a magnetic disk, an aluminum alloy plate blank for a magnetic disk, and an aluminum alloy plate substrate for a magnetic disk, which have good rigidity and are capable of suppressing thermal deformation during magnetic film sputtering.SOLUTION: An aluminum alloy plate for a magnetic disk contains 0.1-7.0 mass % of Mg, 0.005-1.0 mass % of Cr, 3-100 mass ppm of Be, Mn, 100 mass ppm or less of Ti, and 0.20 mass % or less of Si. The total of at least one or more of Fe, Mn, and Ni is 0.03-5.9 mass %, and the remainder comprises Al and impurities. The solid-soluble amount of Mn in an aluminum parent phase is 0.03 mass % or more.SELECTED DRAWING: None

In an amorphous glass for a magnetic recording medium substrate or for a glass spacer for a magnetic recording and reproducing apparatus, an SiO2 content is in a range of 56 mol % or more, an MgO content is in a range of 15 mol % or more and 28 mol % or less, a total content of Al2O3, MgO, and CaO (Al2O3+MgO+CaO) is 29.0 mol % or more and 36.50 mol % or less, the total content of SiO2, MgO, Li2O, Al2O3, and CaO (SiO2+MgO+Li2O+Al2O3+CaO) is 95.0 mol % or more, a mole ratio of the total content of SiO2 and MgO relative to the Li2O content [(SiO2+MgO) / Li2O] is 13 or more, and a mole ratio of a CaO content relative to a total content of Al2O3 and MgO [CaO / (Al2O3+MgO)] is 0.10 or less.

The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder, in which a half-width of a frictional force, which is measured on a surface of the magnetic layer with a lateral force microscope, is 200 mV or less, and standard deviation σ of the half-width of the frictional force in a width direction of the surface of the magnetic layer is 50.0 mV or less.

An alkali-free glass sheet of the present invention contains, as a glass composition, in mol %, from 69% to 76% of SiO2, from 12% to 15% of Al2O3, from 0% to 2% of B2O3, from 0% to 0.5% of Li2O+Na2O+K2O, from 2% to 10% of MgO, from 2% to 12% of CaO, more than 0% to 5% of SrO, more than 0% to 5% of BaO, and from 12% to 18% of MgO+CaO+SrO+BaO, in which a mol % ratio Al2O3 / (MgO+CaO+SrO+BaO) is from 0.5 to 1.5, and a mol % ratio SrO / BaO is from 0.3 to 1.6.

The magnetic tape includes a non-magnetic support, and a magnetic layer containing a ferromagnetic powder. A magnetic tape cartridge and a magnetic tape apparatus include the magnetic tape. Svi obtained by measuring a surface of the magnetic layer with an atomic force microscope and by Equation A is 0.080 or more and 0.130 or less, and standard deviation σ of the Svi in a width direction of the surface of the magnetic layer is 0.010 or less. In Equation A, Sq is a root-mean-square height Sq specified in ISO 25178, Vv(h0.8) is a void volume in a region where a load area ratio in a bearing curve is 80% or more and 100% or less, and A is a measurement region area.Svi=(Vv⁡(h0.8)A) / SqEquation⁢ A

A glass is an amorphous oxide glass. An SiO2 content ranges from 56 mol % to 80 mol %, an Li2O content is 2.00 mol % or less, a B2O3 content ranges from 0 mol % to 4 mol %, a total content of MgO and CaO (MgO+CaO) ranges from 9 mol % to 40 mol %, and the oxide glass has a specific gravity of 2.75 g / cm3 or less, and a glass transition temperature of 650° C. or higher.

A sputtering target according to the present invention contains Co and Pt as metal components, wherein a molar ratio of a content of Pt to a content of Co is from 5 / 100 to 45 / 100, and wherein the sputtering target contains Nb2O5 as a metal oxide component.

Provided is a magnetic tape having a non-magnetic support and a magnetic layer containing a ferromagnetic powder, wherein the protrusion height Spk defined in ISO 25178 is 1.2 to 2.8 nm inclusive, said protrusion height Spk being measured in a measurement region of 5 × 5 μm on the surface of the magnetic layer after 500 cycles of back and forth sliding with respect to an LTO8 head at a head inclination angle of 15° at a temperature of 15°C and a relative humidity of 80%.

An information recording medium disc according to an embodiment is a disc having a plate thickness of 0.51 mm or less, and is provided with a substrate and a cover layer. The substrate has one main surface and another main surface, and also has a side wall surface connecting the two main surfaces. A cover layer covers both main surfaces and side wall surfaces of the substrate. The disk has a specific elastic modulus E / d [106 m2 / s2] of 40 or more as calculated from a Young's modulus E [GPa] and a density d [g / cm3]. When 30 [G] impact of 2 [m seconds is applied to the disk in the normal direction of the main surface of the disk substrate in a state in which the inner peripheral end of the disk is fixed, the maximum amplitude caused by vibration in the thickness direction of the outer peripheral end of the disk substrate is 0.25 mm or less.

Provided is a magnetic tape apparatus. In a case where a maximum value of an absolute value of a difference between a servo band interval obtained before the following storage and a servo band interval obtained after the storage of N cycles, in which a predetermined storage is set as one cycle, is denoted by A, and a medium life is equal to or longer than 5 years, which is calculated by a linear function of A and a logarithm loge T of T derived from a value of A and a value of the logarithm loge T of a total storage time T of the storage of the N cycles, each of which is obtained by setting N as 1, 2, 3, 4, or 5. The medium life is T, in a case where A satisfies Expression a: A=1.5−B+C.

To provide a glass that can suppress the deformation of a glass substrate, is excellent in moldability, and has a low burden on manufacturing equipment.SOLUTION: Provided is an alkali-free glass in which thermal expansion coefficient, Young's modulus, strain point, temperature T4 at which viscosity is 104 dPa s, glass surface devitrification temperature, and temperature T2 at which viscosity is 102 dPa s are within specified range, and contained amount of SiO2, Al2O3, B2O3, MgO, CaO, SrO, and BaO, MgO+CaO+SrO+BaO, and MgO / CaO are within specified range.SELECTED DRAWING: None

A glass substrate for a magnetic recording medium of the present invention has an average coefficient of linear thermal expansion within a temperature range of from 30° C. to 380° C. of from 30×10−7 / ° C. to 40×10−7 / ° C., a Young's modulus of 80 GPa or more, a specific Young's modulus of 30 GPa / g·cm−3 or more, and a strain point of 700° C. or more.

Disks for use in hard disk drives (HDD) or other magnetic recording apparatus. The disks are configured based on a finding that internal stress within a disk can make the disk more resistant to shock forces. In one example, a disk is provided that has a substrate with a thickness of no more than 0.5 millimeters and an internal stress no less than 300 megapascals. The relatively high internal stress within the substrate of the disk serves to reduce the magnitude of deflections caused by mechanical shocks to an HDD in which the disk is installed, as compared to other disks of equal thickness but with relatively less internal stress. Multi-platter stacks of the disks are described. Methods are also described for fabricating such disks and for rejecting disks that do not meet certain internal stress-based criteria. Substrates are also described.

An alkali-free glass sheet according to the present invention contains, as a glass composition, in mol %, from 60% to 80% of SiO2, from 12% to 15% of Al2O3, from 1.2% to 4% of B2O3, from 0% to 0.5% of Li2O+Na2O+K2O, from 2% to 8% of MgO, from 2% to 11% of CaO, from 0% to 5% of SrO, from 0% to 5% of BaO, and from 10% to 16% of MgO+CaO+SrO+BaO, in which a mol % ratio B2O3 / Al2O3 is from 0.1 to 0.3, a mol % ratio (B2O3+BaO) / SiO2 is from 0.01 to 0.1, and MgO+CaO+SrO+BaO—Al2O3 is from −2% to +2%.

A disk-shaped glass substrate manufacturing method for manufacturing a glass substrate (1) includes preparing a disk-shaped glass blank having main surfaces (11a, 11b) and an outer circumferential end face (12), and irradiating the disk-shaped glass blank with a laser beam (L) along a distance longer than one lap of the outer circumferential end face (12) of the disk-shaped glass blank.

To provide a glass which enables suppression of deformation such as warpage of a glass substrate, is excellent in moldability, is low in a burden on a manufacturing facility, is low in a crystal growth rate, and is further excellent in productivity and quality.SOLUTION: An alkali-free glass contains 50 to 80% SiO2, 8 to 20% Al2O3, 0.1% or more B2O3, 1% or more SrO, 1% or more BaO, 0 to 0.2% Li2O+Na2O+K2O, and 0 to 1% P2O5, wherein [MgO] / [CaO] is 1.5 or less, a value of Formula (B) is 710 to 800, a value of Formula (E) is 3.00 to 5.50. The alkali-free glass has a Young's modulus of 83 GPa or more, a strain point of 690°C or higher, T4 of 1,400°C or lower, T2 of 1,800°C or lower, an internal devitrification temperature of 1,320°C or lower, a ηd of 104.4dPa s or more, a ηc of 104.2dPa s or more, a crystal growth rate of 100 μm / hr or less, a density of 2.8 g / cm3 or less, and an average thermal expansion coefficient of 30×10-7 / °C to 45×10-7 / °C.SELECTED DRAWING: None

To provide an aluminum alloy sheet for a magnetic disk, an aluminum alloy sheet blank for the magnetic disk, and an aluminum alloy sheet substrate for the magnetic disk, having satisfactory rigidity and capable of suppressing thermal deformation during magnetic film sputtering.SOLUTION: An aluminum alloy sheet for a magnetic disk, comprising: 0.1 to 7.0 mass% of Mg; 0.005 to 1.0 mass% of Cr; 3 to 100 mass ppm of Be; 0.20 mass% or less of Si; 0.05 to 5.9 mass% of at least one or more of Fe, Mn, and Ni in total; and a balance of Al and impurities.SELECTED DRAWING: None

The present invention relates to an aluminum alloy disc blank for a magnetic disc, characterized by being formed of an aluminum alloy containing Fe: 0.005 to 1.800 mass%, the balance consisting of Al and unavoidable impurities, and a flatness change of the aluminum alloy disc blank for a magnetic disc being 2.0 μm or less when the aluminum alloy disc blank for a magnetic disc is kept in the atmosphere at 50°C or lower for 336 hours.

An alkali-free glass includes, in mol % in terms of oxides: SiO2: 63-75%; Al2O3: 10-16%; B2O3: 0-5%; MgO: 0.1-15%; CaO: 0.1-12%; SrO: 0-8%; and BaO: 0-6%. [MgO] / [CaO] is 1.5 or smaller. A value of Formula (A) is 82.5 or larger. A value of Formula (B) is 690 or larger and 800 or smaller. A value of Formula (C) is 100 or smaller. A value of Formula (D) is 20 or smaller. The alkali-free glass has a Young's modulus of 83 GPa or larger and a surface devitrification viscosity ηc of 104.2 dPa·s or higher.

A magnetic recording medium includes a nonmagnetic substrate, an underlayer disposed above the nonmagnetic substrate, and a magnetic recording layer disposed above the underlayer. The magnetic recording layer includes a first magnetic layer disposed above the underlayer, and a second magnetic layer disposed above the first magnetic layer. Each of the first magnetic layer and the second magnetic layer has a granular structure including magnetic grains having a L10 structure and a grain boundary portion. The grain boundary portion of the first magnetic layer includes aluminum nitride, and the grain boundary portion of the second magnetic layer includes hexagonal boron nitride. An aluminum nitride content in the first magnetic layer is in a range of 15 vol % to 35 vol %, and a peak in a B1s spectrum of the grain boundary portion of the second magnetic layer observed using X-ray photoelectron spectroscopy is 191.6 eV or less.

To provide a glass for a magnetic recording medium substrate having excellent heat resistance and rigidity, a magnetic recording medium substrate made of the glass, a magnetic recording medium including the substrate, and a glass spacer for a magnetic recording device.SOLUTION: A glass for a magnetic recording medium substrate is an amorphous oxide glass having a SiO2 content of 56 to 80 mol%, a Li2O content of 1 to 10 mol%, a B2O3 content of 0 to 4 mol%, a total content of MgO and CaO (MgO+CaO) of 9 to 40 mol%, a specific gravity of 2.75 g / cm3 or less, a glass transition temperature of 650°C or more, and a Young's modulus of 90 GPa or more.SELECTED DRAWING: None