Magnetoresistive head and information regeneration apparatus

A magnetoresistive head, provided with a magnetoresistive film being a multilayered film including:

• a pinned magnetic layer having magnetization whose direction is fixed;
• a free magnetic layer having magnetization whose direction changes in accordance with an external magnetic field;
• and a first nonmagnetic layer held by the pinned magnetic layer and the free magnetic layer in a layer thickness direction, and indicating a magnitude of resistance in accordance with an angle formed by the magnetization direction of the pinned magnetic layer and the magnetization direction of the free magnetic layer, for detecting the magnitude of resistance of the magnetoresistive film to detect a strength of said external magnetic field,
• said magnetoresistive head comprising:
• a second nonmagnetic layer disposed on a side of said free magnetic layer opposite to said first nonmagnetic layer;
• and
• a bias application layer, disposed on a side of said second nonmagnetic layer opposite to said free magnetic layer, for applying, to said free magnetic layer, a bias magnetic field generated by a static interlayer coupling, directed in a direction opposite to the magnetization direction of said pinned magnetic layer and having a strength of 800 A/m or more.

A magnetoresistive head comprising a magnetoresistive film being a multilayered film including:

• a first pinned magnetic layer having magnetization whose direction is fixed;
• a first nonmagnetic layer formed on said first pinned magnetic layer;
• a free magnetic layer formed on said first nonmagnetic layer, and provided with a first soft magnetic layer and a second soft magnetic layer formed of a soft magnetic material and an antiparallel coupling middle layer, formed between the soft magnetic layers, for coupling magnetizations of the soft magnetic layers in opposite directions, in which the magnetization directions of the soft magnetic layers coupled in the opposite directions change in accordance with an external magnetic field;
• a second nonmagnetic layer formed on said free magnetic layer;
• and
• a second pinned magnetic layer formed on said second nonmagnetic layer and provided with magnetization fixed in the same direction as the magnetization direction of said first pinned magnetic layer, and indicating a magnitude of resistance in accordance with an angle formed by the magnetization direction of said first pinned magnetic layer and the magnetization direction of said first soft magnetic layer,
• said magnetoresistive head detecting the magnitude of resistance of the magnetoresistive film to detect a strength of said external magnetic field.

An information regeneration apparatus comprising a magnetic head, disposed in the vicinity of or in contact with a magnetic recording medium on which information is recorded by a magnetization direction, for detecting the magnetization direction of each point of the magnetic recording medium, to regenerate the information in accordance with the magnetization direction of each point of said magnetic recording medium detected by the magnetic head,

• said magnetic head, provided with comprising a magnetoresistive film being a multilayered film including:
• a pinned magnetic layer having magnetization whose direction is fixed;
• a free magnetic layer having magnetization whose direction changes in accordance with an external magnetic field;
• and a first nonmagnetic layer held by the pinned magnetic layer and the free magnetic layer in a layer thickness direction, and indicating a magnitude of resistance in accordance with an angle formed by the magnetization direction of the pinned magnetic layer and the magnetization direction of the free magnetic layer, for detecting the magnitude of resistance of the magnetoresistive film to detect a strength of said external magnetic field,
• said magnetic head comprising:
• a second nonmagnetic layer disposed adjacent to the surface of said free magnetic layer on a side opposite to the side of said first nonmagnetic layer;
• and
• a bias application layer, disposed adjacent to the surface of said second nonmagnetic layer on a side opposite to the side of said free magnetic layer, for applying, to said free magnetic layer, a bias magnetic field generated by a static interlayer coupling and directed in a direction opposite to the magnetization direction of said pinned magnetic layer, the bias application layer comprising a material including at least one material of an antiferromagnetic material of an ordered form and a hard magnetic material.

An information regeneration apparatus comprising a magnetic head, disposed in the vicinity of or in contact with a magnetic recording medium on which information is recorded by a magnetization direction, for detecting the magnetization direction of each point of the magnetic recording medium, to regenerate the information in accordance with the magnetization direction of each point of said magnetic recording medium detected by the magnetic head,

• said magnetic head, provided with a magnetoresistive film being a multilayered film including:
• a pinned magnetic layer having magnetization whose direction is fixed;
• a free magnetic layer having magnetization whose direction changes in accordance with an external magnetic field;
• and a first nonmagnetic layer held by the pinned magnetic layer and the free magnetic layer in a layer thickness direction, and indicating a magnitude of resistance in accordance with an angle formed by the magnetization direction of the pinned magnetic layer and the magnetization direction of the free magnetic layer, for detecting the magnitude of resistance of the magnetoresistive film to detect a strength of said external magnetic field,
• said magnetic head comprising:
• a second nonmagnetic layer disposed on a side of said free magnetic layer opposite to the first nonmagnetic layer;
• and
• a bias application layer, disposed on a side of said second nonmagnetic layer opposite to said free magnetic layer, for applying, to said free magnetic layer, a bias magnetic field generated by a static interlayer coupling, directed in a direction opposite to the magnetization direction of said pinned magnetic layer and having a strength of 800 A/m or more.