Abstract: A magnetic-disk substrate according to an embodiment includes two main surfaces and an outer circumferential edge surface. In the magnetic-disk substrate, the outer circumferential edge surface includes two chamfered surfaces that are respectively connected to the main surfaces, and a side wall surface that is curved and extends to protrude outward between the two chamfered surfaces. The side wall surface has a radius of curvature of 1100 ?m or more on a cross-section of the magnetic-disk substrate extending along a plate thickness direction of the magnetic-disk substrate.

Abstract: A polishing liquid containing: abrasive grains; a first nitrogen-containing compound; a second nitrogen-containing compound; and water, in which the first nitrogen-containing compound contains at least one selected from the group consisting of (I) a compound having an aromatic ring containing one nitrogen atom in the ring and a hydroxyl group, (II) a compound having an aromatic ring containing one nitrogen atom in the ring and a functional group containing a nitrogen atom, (III) a compound having a 6-membered ring containing two nitrogen atoms in the ring, (IV) a compound having a benzene ring and a ring containing a nitrogen atom in the ring, and (V) a compound having a benzene ring to which two or more functional groups containing a nitrogen atom are bonded, and an HLB value of the second nitrogen-containing compound is 7 or more.

Abstract: A polishing liquid includes abrasive grains containing at least one selected from the group consisting of cerium oxide and silicon oxide; a nitrogen-containing compound; and water. The nitrogen-containing compound contains nicotinamide. A polishing liquid set includes constituent components of a polishing liquid stored while being divided into a first liquid and a second liquid. A polishing method includes a step of polishing a surface to be polished by using a polishing liquid.

Abstract: Letting a particle diameter be Dx (?m) when a cumulative particle volume cumulated from the small particle diameter side reaches x (%) of the total particle volume in a particle size distribution obtained regarding cerium oxide included in a polishing liquid using a laser diffraction/scattering method, D5 is 1 ?m or less, D100 is 3 ?m or more, D50 is 0.8 to 2.4 ?m, and Dpeak?D5 is less than D95?Dpeak.

Abstract: A magnetic-disk substrate has an average value of squares of inclinations that is 0.0025 or less, and a frequency at which squares of inclinations are 0.004 or more is 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm. The main surface is configured to receive at least a magnetic recording layer thereon. The magnetic-disk substrate includes an outer circumferential end portion and an inner circumferential end portion, and the outer circumferential end portion and the inner circumferential end portion have chamfered portions.

Abstract: Letting a particle diameter be Dx (?m) when a cumulative particle volume cumulated from the small particle diameter side reaches x (%) of the total particle volume in a particle size distribution obtained regarding cerium oxide included in a polishing liquid using a laser diffraction/scattering method, D5 is 1 ?m or less, and a difference between D95 and D5 is 3 ?m or more.

Abstract: Provided is a CMP polishing liquid used for removing a part of an insulating portion of a base substrate, which includes a substrate, a stopper provided on one surface of the substrate, and the insulating portion provided on a surface of the stopper opposite to the substrate, by CMP to expose the stopper, the polishing liquid containing: abrasive grains containing cerium; a nonionic water-soluble compound A; a polymer compound B having at least one selected from the group consisting of carboxylic acid groups and carboxylate groups; a basic pH adjusting agent which is optionally contained; and water, in which a content of the basic pH adjusting agent is less than 1.3×10?2 mol/kg based on the total mass of the polishing liquid.

Abstract: A magnetic-disk substrate has an average value of squares of inclinations that is 0.0025 or less, and a frequency at which squares of inclinations are 0.004 or more is 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm. The main surface is configured to receive at least a magnetic recording layer thereon. The magnetic-disk substrate includes an outer circumferential end portion and an inner circumferential end portion, and the outer circumferential end portion and the inner circumferential end portion have chamfered portions.

Abstract: Chamfering processing for chamfering an edge face of a disk-shaped glass plate includes a step of disposing the glass plate such that a portion of the glass plate is disposed in a heating space for heating the glass plate and the remaining portion is disposed outside the heating space; and a step of softening a portion of the edge face of the glass plate by irradiating a circumferential portion of the edge face with a laser beam outside the heating space while rotating the glass plate in one direction around the center of the glass plate, and heating the softened portion of the edge face that has reached the heating space through the rotation.

Abstract: A polishing liquid containing: abrasive grains; a first nitrogen-containing compound; a second nitrogen-containing compound; and water, in which the first nitrogen-containing compound contains at least one selected from the group consisting of (I) a compound having an aromatic ring containing one nitrogen atom in the ring and a hydroxyl group, (II) a compound having an aromatic ring containing one nitrogen atom in the ring and a functional group containing a nitrogen atom, (III) a compound having a 6-membered ring containing two nitrogen atoms in the ring, (IV) a compound having a benzene ring and a ring containing a nitrogen atom in the ring, and (V) a compound having a benzene ring to which two or more functional groups containing a nitrogen atom are bonded, and an HLB value of the second nitrogen-containing compound is 7 or more.

Abstract: Letting a particle diameter be Dx (?m) when a cumulative particle volume cumulated from the small particle diameter side reaches x (%) of the total particle volume in a particle size distribution obtained regarding cerium oxide included in a polishing liquid using a laser diffraction/scattering method, D5 is 1 ?m or less, and a difference between D95 and D5 is 3 ?m or more.

Abstract: Letting a particle diameter be Dx (?m) when a cumulative particle volume cumulated from the small particle diameter side reaches x (%) of the total particle volume in a particle size distribution obtained regarding cerium oxide included in a polishing liquid using a laser diffraction/scattering method, D5 is 1 ?m or less, and a difference between D95 and D5 is 3 ?m or more.

Abstract: A magnetic-disk substrate has an average value of squares of inclinations that is 0.0025 or less, and a frequency at which squares of inclinations are 0.004 or more is 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm. The main surface is configured to receive at least a magnetic recording layer thereon. The magnetic-disk substrate includes an outer circumferential end portion and an inner circumferential end portion, and the outer circumferential end portion and the inner circumferential end portion have chamfered portions.

Abstract: A hard disk drive includes a magnetic-disk substrate in which an average value of squares of inclinations is 0.0025 or less and a frequency at which squares of inclinations are 0.004 or more is 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm.

Abstract: Provided is a CMP polishing liquid used for removing a part of an insulating portion of a base substrate, which includes a substrate, a stopper provided on one surface of the substrate, and the insulating portion provided on a surface of the stopper opposite to the substrate, by CMP to expose the stopper, the polishing liquid containing: abrasive grains containing cerium; a nonionic water-soluble compound A; a polymer compound B having at least one selected from the group consisting of carboxylic acid groups and carboxylate groups; a basic pH adjusting agent which is optionally contained; and water, in which a content of the basic pH adjusting agent is less than 1.3×10?2 mol/kg based on the total mass of the polishing liquid.

Abstract: A polishing liquid containing: abrasive grains containing at least one selected from the group consisting of cerium oxide and silicon oxide; a nitrogen-containing compound; and water, in which the nitrogen-containing compound contains at least one selected from the group consisting of (I) a compound having an aromatic ring containing one nitrogen atom in the ring and a hydroxyl group, (II) a compound having an aromatic ring containing one nitrogen atom in the ring and a functional group containing a nitrogen atom, (III) a compound having a 6-membered ring containing two nitrogen atoms in the ring, (IV) a compound having a benzene ring and a ring containing a nitrogen atom in the ring, and (V) a compound having a benzene ring to which two or more functional groups containing a nitrogen atom are bonded.

Abstract: Letting a particle diameter be Dx (?m) when a cumulative particle volume cumulated from the small particle diameter side reaches x(%) of the total particle volume in a particle size distribution obtained regarding cerium oxide included in a polishing liquid using a laser diffraction/scattering method, D5 is 1 ?m or less, and a difference between D95 and D5 is 3 ?m or more.

Abstract: A magnetic disk substrate having a flat main surface, an end face, and a chamfered face formed between the main surface and the end face. The substrate has an offset portion, present on the main surface within a range of 92.0 to 97.0% in a radial direction from a center of the substrate. A distance from the center of the substrate to the end face of the substrate in a radial direction is 100%, the offset portion being raised or lowered with respect to a virtual straight line connecting two points on the main surface, set at positions of 92.0% and 97.0%. A maximum distance from the virtual straight line to the offset portion in a direction perpendicular to the virtual straight line is a “maximum offset value.

Abstract: A hard disk drive includes a magnetic-disk substrate in which an average value of squares of inclinations is 0.0025 or less and a frequency at which squares of inclinations are 0.004 or more is 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm.

Abstract: A magnetic-disk glass substrate of the present invention has an average value of squares of inclinations of 0.0025 or less and a frequency at which squares of inclinations are 0.004 or more of 15% or less, in a case where samples of inclinations on a main surface are obtained at intervals of 10 nm.