MAGNETIC TAPE AND MAGNETIC TAPE DEVICE

• US 20180374507A1
• Filed: 06/15/2018
• Published: 12/27/2018
• Est. Priority Date: 06/23/2017
• Status: Active Grant

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Inventors: KASADA, Norihito
• Granted Patent: US 10,366,721 B2
• Time in Patent Office: Days
• CPC Class Codes: G11B 20/1201 on tapes
• CPC Class Codes: G11B 5/00813 magnetic tapes
• CPC Class Codes: G11B 5/00817 on longitudinal tracks only, e.g. for serpentine format recording
• CPC Class Codes: G11B 5/3906 Details related to the use of magnetic thin film layers or to their effects
• CPC Class Codes: G11B 5/3909 Arrangements using a magnetic tunnel junction
• CPC Class Codes: G11B 5/584 for track following on tapes
• CPC Class Codes: G11B 5/5926 recorded in separate tracks, e.g. servo tracks
• CPC Class Codes: G11B 5/70 on a base layer
• CPC Class Codes: G11B 5/70615 containing Fe metal or alloys G11B5/70621 takes precedence
• CPC Class Codes: G11B 5/70678 Ferrites
• CPC Class Codes: G11B 5/712 characterised by the surface treatment or coating of magnetic particles

Abstract

The magnetic tape includes a non-magnetic support; and a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support, in which the magnetic layer includes a timing-based servo pattern, the ferromagnetic powder is ferromagnetic hexagonal ferrite powder having an activation volume equal to or smaller than 1,600 nm³, an XRD intensity ratio Int(110)/Int(114) obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0, a vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00, and an edge shape of the timing-based servo pattern specified by magnetic force microscope observation is a shape in which a difference (L_99.9−L_0.1) is equal to or smaller than 180 nm, and a magnetic tape device including the magnetic tape.

Claims

1. A magnetic tape comprising:

a non-magnetic support; and

a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support,

wherein the magnetic layer includes a timing-based servo pattern,

the ferromagnetic powder is ferromagnetic hexagonal ferrite powder having an activation volume equal to or smaller than 1,600 nm³,

an intensity ratio Int(110)/Int(114) of a peak intensity Int(110) of a diffraction peak of a (110) plane with respect to a peak intensity Int(114) of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0,

a vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00, and

an edge shape of the timing-based servo pattern specified by magnetic force microscope observation is a shape in which a difference (L_99.9−

L_0.1) of a value L_99.9 of a cumulative distribution function of 99.9% of a position shift width from an ideal shape in a longitudinal direction of the magnetic tape and a value L_0.1 of the cumulative distribution function of 0.1% is equal to or smaller than 180 nm.

2. The magnetic tape according to claim 1,

wherein the timing-based servo pattern is a linear servo pattern which continuously or discontinuously extends from one side to the other side in a width direction of the magnetic tape.

3. The magnetic tape according to claim 2,

wherein the timing-based servo pattern is a linear servo pattern which continuously extends from one side to the other side in the width direction of the magnetic tape and which is tilted with respect to the width direction by an angle of α

, and

the ideal shape is a linear shape extending in a direction of the angle α

.

4. The magnetic tape according to claim 1,

wherein the vertical direction squareness ratio of the magnetic tape is 0.65 to 0.90.

5. The magnetic tape according to claim 1,

wherein the difference (L_99.9−

L_0.1) is equal to or smaller than 150 nm.

6. The magnetic tape according to claim 1,

wherein the activation volume of the ferromagnetic hexagonal ferrite powder is 800 nm³ to 1,600 nm³.

7. The magnetic tape according to claim 1, further comprising:

a non-magnetic layer including non-magnetic powder and a binding agent between the non-magnetic support and the magnetic layer.

8. A magnetic tape device comprising:

a magnetic tape;

a magnetic head; and

a servo head,

wherein the magnetic tape is a magnetic tape comprising;

a non-magnetic support; and

a magnetic layer including ferromagnetic powder and a binding agent on the non-magnetic support,

wherein the magnetic layer includes a timing-based servo pattern,

the ferromagnetic powder is ferromagnetic hexagonal ferrite powder having an activation volume equal to or smaller than 1,600 nm³,

an intensity ratio Int(110)/Int(114) of a peak intensity Int(110) of a diffraction peak of a (110) plane with respect to a peak intensity Int(114) of a diffraction peak of a (114) plane of a hexagonal ferrite crystal structure obtained by an X-ray diffraction analysis of the magnetic layer by using an In-Plane method is 0.5 to 4.0,

a vertical direction squareness ratio of the magnetic tape is 0.65 to 1.00, and

an edge shape of the timing-based servo pattern specified by magnetic force microscope observation is a shape in which a difference (L_99.9−

L_0.1) of a value L_99.9 of a cumulative distribution function of 99.9% of a position shift width from an ideal shape in a longitudinal direction of the magnetic tape and a value

9. The magnetic tape device according to claim 8,

wherein the timing-based servo pattern is a linear servo pattern which continuously or discontinuously extends from one side to the other side in a width direction of the magnetic tape.

10. The magnetic tape device according to claim 9,

wherein the timing-based servo pattern is a linear servo pattern which continuously extends from one side to the other side in the width direction of the magnetic tape and which is tilted with respect to the width direction by an angle of α

, and

the ideal shape is a linear shape extending in a direction of the angle α

.

11. The magnetic tape device according to claim 8,

wherein the vertical direction squareness ratio of the magnetic tape is 0.65 to 0.90.

12. The magnetic tape device according to claim 8,

wherein the difference (L_99.9−

L_0.1) is equal to or smaller than 150 nm.

13. The magnetic tape device according to claim 8,

wherein the activation volume of the ferromagnetic hexagonal ferrite powder is 800 nm³ to 1,600 nm³.

14. The magnetic tape device according to claim 8,

wherein the magnetic tape further comprises a non-magnetic layer including non-magnetic powder and a binding agent between the non-magnetic support and the magnetic layer.