Magnetic recording device

Abstract

A magnetic recording device which can write magnetic information with high density. The device uses, for a magnetic recording layer of a magnetic recording medium, a magnetic material whose anisotropy energy varies with an applied electric field. The head has an electrode for applying an electric field to a recording area of the magnetic recording medium. Magnetic recording is performed by applying an AC electric field from the electrode while a DC magnetic field is applied to the recording area of the magnetic recording layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more particularly described with reference to the accompanying drawings, in which:

FIG. 1 is a conceptual diagram showing a magnetic recording and reproduction device according to an embodiment of the present invention;

FIGS. 2A to 2C show the relationships between magnetization curves and external magnetic fields and recording conditions, wherein FIG. 2A shows that at E=0 magnetized state M_L is held with a large coercivity; FIG. 2B shows that at E=E₀ magnetized state M_H is held with a small coercivity; and FIG. 2C shows that at E=0 magnetized state M_H is held with a large coercivity;

FIG. 3 is a conceptual diagram showing a magnetic recording and reproduction device according to another embodiment of the present invention;

FIG. 4 show the relationships between magnetization curves and external magnetic fields and recording conditions, wherein FIG. 4A shows a large coercivity at E=0; FIG. 4B shows a small coercivity at E=E₀; and FIG. 4C shows that at E=0 magnetized state M_H or M_L is held;

FIG. 5 is a conceptual diagram showing a magnetic recording and reproduction device according to another embodiment of the present invention;

FIG. 6 schematically shows an example of a magnetic head structure according to an embodiment of the present invention;

FIG. 7 schematically shows an example of a magnetic head structure according to an embodiment of the present invention;

FIG. 8 schematically shows an example of a magnetic disk device structure according to an embodiment of the present invention; and

FIG. 9 schematically shows an example of a magnetic disk device structure according to an embodiment of the present invention.

Claims

1. A magnetic recording device, comprising: a magnetic recording medium having a magnetic recording layer comprising a magnetic material with an anisotropy energy that varies with applied external energy;external energy application means that applies the external energy to the magnetic recording medium; andmagnetic field application means that applies a magnetic field to the magnetic recording medium,wherein magnetic information is written to the magnetic recording medium by applying magnetic field and the external energy.

2. The magnetic recording device according to claim 1, wherein coercivity of the magnetic material decreases when the electric field is applied.

3. A magnetic recording device comprising: a magnetic recording medium having a magnetic recording layer comprising a magnetic material with an anisotropy energy that varies with an applied electric field;a drive which drives the magnetic recording medium;a head comprising an electrode for applying at least a DC one of the assisting electric field to a recording area of the magnetic recording layer and a magnetic pole for applying a magnetic field to the recording area; andan actuator which moves the head to a desired position of the magnetic recording medium,wherein magnetic recording is performed by applying an AC one of the magnetic field from the magnetic pole and the DC assisting electric field to the magnetic recording layer.

4. The magnetic recording device according to claim 3, wherein the electrode is located between a pair of the magnetic poles for applying the magnetic field to the recording area.

5. The magnetic recording device according to claim 3, wherein the coercivity of the magnetic material decreases when the assisting electric field is applied.

6. The magnetic recording device according to claim 3, wherein the magnetic material of the magnetic recording medium is a magnetic semiconductor material.

7. The magnetic recording device according to claim 3, wherein the magnetic material of the magnetic recording medium is one selected from Mn-doped GaAs compound, Mn-doped InAs compound, and a material which comprised of one of GaN and ZnO.

8-12. (canceled)

13. The magnetic recording device according to claim 1, wherein the magnetic recording layer is readily magnetizable in a direction perpendicular to at least an upper surface of said recording medium.

14. (canceled)

15. The magnetic recording device according to claim 1, wherein the magnetic recording layer is readily magnetizable in a direction longitudinal to at least an upper surface of said recording medium.

16. (canceled)