Magnetic head for perpendicular magnetic recording with controlled state of magnetization of the end face of the pole layer

A head gimbal assembly comprising:

• a slider including a magnetic head for perpendicular magnetic recording and disposed to face toward a recording medium;
• and a suspension flexibly supporting the slider, wherein:
• the magnetic head comprises:
• a medium facing surface that faces toward the recording medium;
• a coil for generating a magnetic field corresponding to data to be written on the recording medium;
• and
• a pole layer allowing a magnetic flux corresponding to the field generated by the coil to pass therethrough, and generating a write magnetic field for writing the data on the recording medium by means of a perpendicular magnetic recording system, wherein:
• the pole layer incorporates a track width defining portion and a wide portion that is located away from the medium facing surface and coupled to the track width defining portion;
• the track width defining portion has an end face that is located in the medium facing surface and that defines a track width;
• a maximum width of the wide portion is greater than the track width and equal to or greater than a length of the wide portion taken in a direction orthogonal to the medium facing surface;
• the pole layer is made of a magnetic material and does not include any nonmagnetic layer inside;
• and
• when the coil is generating no magnetic field, in the end face of the track width defining portion, there exist a first region and a second region in which directions of components of magnetization orthogonal to the medium facing surface are opposite.

A head arm assembly comprising:

• a slider including a magnetic head for perpendicular magnetic recording and disposed to face toward a recording medium;
• a suspension flexibly supporting the slider;
• and an arm for making the slider travel across tracks of the recording medium, the suspension being attached to the arm, wherein:
• the magnetic head comprises:
• a medium facing surface that faces toward the recording medium;
• a coil for generating a magnetic field corresponding to data to be written on the recording medium;
• and
• a pole layer allowing a magnetic flux corresponding to the field generated by the coil to pass therethrough, and generating a write magnetic field for writing the data on the recording medium through the use of a perpendicular magnetic recording system, wherein:
• the pole layer incorporates a track width defining portion and a wide portion that is located away from the medium facing surface and coupled to the track width defining portion;
• the track width defining portion has an end face that is located in the medium facing surface and that defines a track width;
• a maximum width of the wide portion is greater than the track width and equal to or greater than a length of the wide portion taken in a direction orthogonal to the medium facing surface;
• the pole layer is made of a magnetic material and does not include any nonmagnetic layer inside;
• and
• when the coil is generating no magnetic field, in the end face of the track width defining portion, there exist a first region and a second region in which directions of components of magnetization orthogonal to the medium facing surface are opposite.

A magnetic disk drive comprising:

• a slider including a magnetic head for perpendicular magnetic recording and disposed to face toward a recording medium that is driven to rotate;
• and an alignment device supporting the slider and aligning the slider with respect to the recording medium, wherein:
• the magnetic head comprises:
• a medium facing surface that faces toward the recording medium;
• a coil for generating a magnetic field corresponding to data to be written on the recording medium;
• and
• a pole layer allowing a magnetic flux corresponding to the field generated by the coil to pass therethrough, and generating a write magnetic field for writing the data on the recording medium through the use of a perpendicular magnetic recording system, wherein:
• the pole layer incorporates a track width defining portion and a wide portion that islocated away from the medium facing surface and coupled to the track width defining portion;
• the track width defining portion has an end face that is located in the medium facing surface and that defines a track width;
• a maximum width of the wide portion is greater than the track width and equal to or greater than a length of the wide portion taken in a direction orthogonal to the medium facing surface;
• the pole layer is made of a magnetic material and does not include any nonmagnetic layer inside;
• and
• when the coil is generating no magnetic field, in the end face of the track width defining portion, there exist a first region and a second region in which directions of components of magnetization orthogonal to the medium facing surface are opposite.