Magnetic disc apparatus

A magnetic disc apparatus comprising a magnetic head of magneto-resistance effect type including:

• a magneto-resistance effect film for sensing an external magnetization and changing the direction of magnetization, said magneto-resistance effect film being a ferromagnetic film in which an electrical resistance thereof changes in accordance with the direction of magnetization;
• a pair of electrodes for supplying a current to said magneto-resistance effect film;
• and
• a magnetic domain control layer of antiferromagnetic material for controlling the magnetic domain of said magneto-resistance effect film;
• said magnetic disc apparatus comprising said magnetic head of magneto-resistance effect type further including a non-magnetic film formed narrower than the length of said magneto-resistance effect film and wider than the interval of said electrodes between said magneto-resistance effect film and said magnetic domain control layer and in contact with said magneto-resistance effect film and said magnetic domain control layer for breaking the magnetic coupling between said magneto-resistance effect film and said magnetic domain control layer, and a ferromagnetic film having a soft magnetic characteristic for applying a laterally biasing magnetic field to said magneto-resistance effect film being provided at an opposite side of said magneto-resistance effect film from that of said magnetic domain control layer of antiferromagnetic material so that said magneto-resistance effect film is disposed between said magnetic domain control layer of antiferromagnetic material and said ferromagnetic film having the soft magnetic characteristic.

A magnetic disc apparatus comprising a thin-film dual magnetic head including a reproduction head and a recording head:

• said reproduction head including a magneto-resistance effect film for converting a magnetic signal into an electrical signal by use of the magneto-resistance effect, said magneto-resistance effect film being a ferromagnetic film in which an electrical resistance thereof changes in accordance with a direction of magnetization, a pair of electrodes for supplying a signal detection current to said magneto-resistance effect film, and a magnetic domain control layer of antiferromagnetic material for controlling the magnetic domain of said magneto-resistance effect film;
• said recording head including a first magnetic pole, a second magnetic pole in contact with one side of said first magnetic pole and forming a gap with the other side of said first magnetic pole, and a coil wound between said magnetic poles, said recording head converting the current flowing in said coil into a magnetization;
• said magnetic disc apparatus comprising said thin dual magnetic head basically including said reproduction head and said recording head further including an isolation film of a non-magnetic material disposed between said magneto-resistance effect film and said magnetic domain control layer and in contact with said magnetic-resistance effect film and said magnetic domain control layer for breaking the magnetic coupling between said magneto-resistance effect film and said magnetic domain control layer, said isolation film having a length of at least 1 .mu.m and being smaller than a track width of said recording head and a ferromagnetic film having a soft magnetic characteristic for applying a laterally biasing magnetic field to said magneto-resistance effect film being provided at an opposite side of said magneto-resistance effect film from that of said magnetic domain control layer of antiferromagnetic material so that said magneto-resistance effect film is disposed between said magnetic domain control layer of antiferromagnetic material and said ferromagnetic film having the soft magnetic characteristic.

A magnetic disc apparatus comprising a magnetic head of magneto-resistance effect type including:

• a magneto-resistance effect film for converting a magnetic signal into an electrical signal by use of the magneto-resistance effect, said magneto-resistance effect film being a ferromagnetic film in which an electrical resistance thereof changes in accordance with a direction of magnetization;
• a pair of electrodes for supplying a signal detection current to said magneto-resistance effect film;
• and
• a magnetic domain control layer of antiferromagnetic material for controlling the magnetic domain of said magneto-resistance effect film;
• said magnetic disc apparatus comprising said magnetic head of magneto-resistive effect type further including an alteration layer as a paramagnetized magnetic domain control layer in a part of the interface of said magnetic domain control layer in contact with said magneto-resistance effect film and said magnetic domain control layer, and a ferromagnetic film having a soft magnetic characteristic for applying a laterally biasing magnetic field to said magneto-resistance effect film being provided at an opposite side of said magneto-resistance effect film from that of said magnetic domain control layer of antiferromagnetic material so that said magneto-resistance effect film is disposed between said magnetic domain control layer of antiferromagnetic material and said ferromagnetic film having the soft magnetic characteristic.

A magnetic disc apparatus comprising a magnetic head of magneto-resistance effect type including:

• a magneto-resistance effect film for converting a magnetic signal into an electric signal by use of the magneto-resistance effect, said magneto-resistance effect film being a ferromagnetic film in which an electrical resistance thereof changes in accordance with a direction of magnetization;
• a pair of electrodes for supplying the signal detection current to said magneto-resistance film;
• and
• a magnetic domain control layer of antiferromagnetic material for applying a vertically biasing magnetic field to said magneto-resistance effect film;
• said magnetic disc apparatus comprising said magnetic head of magneto-resistance effect type further including an isolation film of a non-magnetic material formed in a magneto-sensitive portion of said magneto-resistance effect film between said magneto-resistance effect film and said magnetic domain control layer and in contact with said magneto-resistance effect film and said magnetic domain control layer for breaking the magnetic coupling between said magneto-resistance effect film and said magnetic domain control layer, and a ferromagnetic film having a soft magnetic characteristic for applying a laterally biasing magnetic field to said magneto-resistance effect film being provided at an opposite side of said magneto-resistance effect film from that of said magnetic domain control layer of antiferromagnetic material so that said magneto-resistance effect film is disposed between said magnetic domain control layer of antiferromagnetic material and said ferromagnetic film having the soft magnetic characteristic.

A magnetic disc apparatus comprising a magnetic head of magneto-resistance effect type including:

• a magneto-resistance effect film for converting a magnetic signal into an electrical signal by use of the magneto-resistance effect;
• a pair of electrodes for supplying a signal detection current to said magneto-resistance effect film;
• and
• a magnetic domain control layer of antiferromagnetic material for applying a vertical biasing magnetic field to said magnetic-resistance effect film;
• said magnetic disc apparatus comprising said magnetic head of magneto-resistance effect type further including an isolation film disposed on said magnetic domain control layer at a portion thereof corresponding to the central part of said magneto-resistance effect film to remove magnetic coupling between said magnetic domain control layer and magneto-resistance effect film, said magneto-resistance effect film being disposed covering both said isolation film and end portions of said isolation film where no isolation film is disposed, so as to create regions where said magnetic domain control layer and magneto-resistance effect film are in direct contact with each other at said end portions of said isolation film, and a ferromagnetic film having a soft magnetic characteristic for applying a laterally biasing magnetic field to said magneto-resistance effect film being provided at an opposite side of said magneto-resistance effect film from that of said magnetic domain control layer of antiferromagnetic material so that said magneto-resistance effect film is disposed between said magnetic domain control layer of antiferromagnetic material and said ferromagnetic film having the soft magnetic characteristic.

A magnetic disc apparatus comprising a magnetic head of magneto-resistance effect type including:

• a magneto-resistance effect film for converting a magnetic signal into an electrical signal by use of the magneto-resistance effect film;
• and
• a magnetic domain control layer of antiferromagnetic material for applying a vertical biasing magnetic field to said magneto-resistance film;
• said magnetic disc apparatus comprising said magnetic head of magneto-resistance effect type further including an isolation film disposed on said magnetic domain control layer at a portion thereof corresponding to the central part of said magneto-resistance effect film to remove magnetic coupling between said magnetic domain control layer and magneto-resistance effect film, said magneto-resistance effect film being disposed covering both said isolation film and end portions of said isolation film where no isolation film is disposed, so as to create regions where said magnetic domain control layer and magneto-resistance effect film are magnetically coupled with each other at said end portions of said isolation film, and a ferromagnetic film having a soft magnetic characteristic for applying a laterally biasing magnetic field to said magneto-resistance effect film being provided at an opposite side of said magneto-resistance effect film from that of said magnetic domain control layer of antiferromagnetic material so that said magneto-resistance effect film is disposed between said magnetic domain control layer of antiferromagnetic material and said ferromagnetic film having the soft magnetic characteristic.

A magnetic disc apparatus comprising a magnetic head of magneto-resistance effect type including:

• a magneto-resistance effect film for sensing an external magnetization and changing the direction of magnetization, said magneto-resistance effect film being a ferromagnetic film in which an electrical resistance thereof changes in accordance with the direction of magnetization;
• a pair of electrodes for supplying a current to said magneto-resistance effect film;
• and
• a magnetic domain control layer of antiferromagnetic material for controlling the magnetic domain of said magneto-resistance effect film;
• and
• said magnetic disc apparatus comprising said magnetic head of magneto-resistance effect type further including a non-magnetic film formed narrower than the length of said magneto-resistance effect film and narrower than the interval of said electrodes between said magneto-resistance effect film and said magnetic domain control layer, and a ferromagnetic film having a soft magnetic characteristic for applying a laterally biasing magnetic field to said magneto-resistance effect film being provided at an opposite side of said magneto-resistance effect film from that of said magnetic domain control layer of antiferromagnetic material so that said magneto-resistance effect film is disposed between said magnetic domain control layer of antiferromagnetic material and said ferromagnetic film having the soft magnetic characteristic.

A magnetic disc apparatus comprising a magnetic head of magneto-resistance effect type including:

• a magneto-resistance effect film for converting a magnetic signal into an electrical signal by use of the magneto-resistance effect, said magneto-resistance effect film being a ferromagnetic film in which an electrical resistance thereof changes in accordance with a direction of magnetization;
• a pair of electrodes for supplying a signal detection current to said magneto-resistance effect film;
• and
• a magnetic domain control layer of antiferromagnetic material for controlling the magnetic domain of said magneto-resistance effect film;
• said magnetic disc apparatus comprising said magnetic head of magneto-resistance effect type further including an isolation film of a non-magnetic material formed in a magneto-sensitive portion of said magneto-resistance effect film between said magneto-resistance effect film and said magnetic domain control layer and in contact with said magneto-resistance effect film and said magnetic domain control layer for breaking the magnetic coupling between said magneto-resistance effect film and said magnetic domain control layer, and at least one of a shunt film and a soft film, said shunt film being made of a non-magnetic metal film disposed in contact with said magneto-resistance effect film so as to apply a lateral biasing magnetic field to said magneto-resistance effect film, said soft film being made of a ferromagnetic film having a soft magnetic characteristic formed through a non-magnetic layer.

A magnetic disc apparatus comprising a magnetic head of magneto-resistance effect type including:

• a magneto-resistance effect film for sensing an external magnetization and changing the direction of magnetization, said magneto-resistance effect film being a ferromagnetic film in which an electrical resistance thereof changes in accordance with the direction of magnetization;
• a pair of electrodes for supplying a current to said magneto-resistance effect film;
• and
• a magnetic domain control layer of antiferromagnetic material for controlling the magnetic domain of said magneto-resistance effect film;
• said magnetic disc apparatus comprising said magnetic head of magneto-resistance effect type further including a non-magnetic film formed narrower than the length of said magneto-resistance effect film and wider than the interval of said electrodes between said magneto-resistance effect film and said magnetic domain control layer and in contact with said magneto-resistance effect film and said magnetic domain control layer, at least one of a shunt film and a soft film, said shunt film being made of a non-magnetic metal film disposed in contact with said magneto-resistance effect film so as to apply a lateral biasing magnetic field to said magneto-resistance effect film, said soft film being made of a ferromagnetic film having a soft magnetic characteristic formed through a non-magnetic layer.

A magnetic disc apparatus comprising a magnetic head of magneto-resistance effect type including:

• a magneto-resistance effect film for converting a magnetic signal into an electric signal by use of the magneto-resistance effect, said magneto-resistance effect film being a ferromagnetic film in which an electrical resistance thereof changes in accordance with a direction of magnetization;
• a pair of electrodes for supplying the signal detection current to said magneto-resistance film;
• and
• a magnetic domain control layer of antiferromagnetic material for applying a vertically biasing magnetic field to said magneto-resistance effect film;
• said magnetic disc apparatus comprising said magnetic head of magneto-resistance effect type further including an isolation film of a non-magnetic material formed in a magneto-sensitive portion of said magneto-resistance effect film between said magneto-resistance effect film and said magnetic domain control layer and in contact with said magneto-resistance effect film and said magnetic domain control layer for breaking the magnetic coupling between said magneto-resistance effect film and said magnetic domain control layer, at least one of a shunt film and a soft film, said shunt film being made of a non-magnetic metal film disposed in contact with said magneto-resistance effect film so as to apply a lateral biasing magnetic field to said magneto-resistance effect film, said soft film being made of a ferromagnetic film having a soft magnetic characteristic formed through a non-magnetic layer.

A magnetic disc apparatus comprising a magnetic head of magneto-resistance effect type including:

• a magneto-resistance effect film for converting a magnetic signal into an electrical signal by use of the magneto-resistance effect, said magneto-resistance effect film being a ferromagnetic film in which an electrical resistance thereof changes in accordance with a direction of magnetization;
• a pair of electrodes for supplying a signal detection current to said magneto-resistance effect film;
• and
• a magnetic domain control layer of antiferromagnetic material for controlling the magnetic domain of said magneto-resistance effect film;
• said magnetic disc apparatus comprising said magnetic head of magneto-resistive effect type further including an alteration layer as a paramagnetized magnetic domain control layer in a part of the interface of said magnetic domain control layer in contact with said magneto-resistance effect film and said magnetic domain control layer, at least one of a shunt film and a soft film, said shunt film being made of a non-magnetic metal film disposed in contact with said magneto-resistance effect film so as to apply a lateral biasing magnetic field to said magneto-resistance effect film, said soft film being made of a ferromagnetic film having a soft magnetic characteristic formed through a non-magnetic layer.

A magnetic disc apparatus comprising a magnetic head of magneto-resistance effect type including:

• a magneto-resistance effect film for converting a magnetic signal into an electric signal by use of the magneto-resistance effect, said magneto-resistance effect film being a ferromagnetic film in which an electrical resistance thereof changes in accordance with a direction of magnetization;
• a pair of electrodes for supplying the signal detection current to said magneto-resistance film;
• and
• a magnetic domain control layer of antiferromagnetic material for applying a vertically biasing magnetic field to said magneto-resistance effect film;
• said magnetic disc apparatus comprising said magnetic head of magneto-resistance effect type further including an isolation film of a non-magnetic material formed in a magneto-sensitive portion of said magneto-resistance effect film between said magneto-resistance effect film and said magnetic domain control layer and in contact with said magneto-resistance effect film and said magnetic domain control layer for breaking the magnetic coupling between said magneto-resistance effect film and said magnetic domain control layer, at least one of a shunt film and a soft film, said shunt film being made of a non-magnetic metal film disposed in contact with said magneto-resistance effect film so as to apply a lateral biasing magnetic field to said magneto-resistance effect film, said soft film being made of a ferromagnetic film having a soft magnetic characteristic formed through a non-magnetic layer.

A magnetic disc apparatus comprising a magnetic head of magneto-resistance effect type including:

• a magneto-resistance effect film for converting a magnetic signal into an electrical signal by use of the magneto-resistance effect;
• a pair of electrodes for supplying a signal detection current to said magneto-resistance effect film;
• and a magnetic domain control layer of antiferromagnetic material for applying a vertical biasing magnetic field to said magnetic-resistance effect film;
• said magnetic disc apparatus comprising said magnetic head of magneto-resistance effect type further including an isolation film disposed on said magnetic domain control layer at a portion thereof corresponding to the central part of said magneto-resistance effect film to remove magnetic coupling between said magnetic domain control layer and magneto-resistance effect film, said magneto-resistance effect film being posed covering both said isolation film and end portions of said isolation film where no isolation film is disposed, so as to create regions where said magnetic domain control layer and magneto-resistance effect film are in direct contact with each other at said end portions of said isolation film, at least one of a shunt film and a soft film, said shunt film being made of a non-magnetic metal film disposed in contact with said magneto-resistance effect film so as to apply a lateral biasing magnetic field to said magneto-resistance effect film, said soft film being made of a ferromagnetic film having a soft magnetic characteristic formed through a non-magnetic layer.

A magnetic disc apparatus comprising a magnetic head of magneto-resistance effect type including:

• a magneto-resistance effect film for converting a magnetic signal into an electrical signal by use of the magneto-resistance effect film;
• and
• a magnetic domain control layer of antiferromagnetic material for applying a vertical biasing magnetic field to said magneto-resistance film;
• said magnetic disc apparatus comprising said magnetic head of magneto-resistance effect type further including an isolation film disposed on said magnetic domain control layer at a portion thereof corresponding to the central part of said magneto-resistance effect film to remove magnetic coupling between said magnetic domain control layer and magneto-resistance effect film, said magneto-resistance effect film being disposed covering both said isolation film and end portions of said isolation film where no isolation film is disposed, so as to create regions where said magnetic domain control layer and magneto-resistance effect film are magnetically coupled with each other at said end portions of said isolation film, at least one of a shunt film and a soft film, said shunt film being made of a non-magnetic metal film disposed in contact with said magneto-resistance effect film so as to apply a lateral biasing magnetic field to said magneto-resistance effect film, said soft film being made of a ferromagnetic film having a soft magnetic characteristic formed through a non-magnetic layer.