Magnetic head and disk device having the same

Abstract

A magnetic head includes a main magnetic pole, a write shield separated from the main magnetic pole by a write gap, a first side shield that is separated from the main magnetic pole by a first side gap, a second side shield that is separated from the main magnetic pole by a second side gap, a first layer that has a first magnetic relative permeability and is disposed in the write gap between the main magnetic pole and the write shield, and a second layer that has a second magnetic relative permeability and is disposed in the first side gap and the second side gap, wherein the first magnetic relative permeability is smaller than the second magnetic relative permeability.

What is claimed is: 
     
         1 . A magnetic head comprising:
 a main magnetic pole that generates a recording magnetic field;   a write shield disposed adjacent to the main magnetic pole and separated from the main magnetic pole by a write gap;   a first side shield that is disposed on a first side of the main magnetic pole in a track width direction from the main magnetic pole and is separated from the main magnetic pole by a first side gap;   a second side shield that is disposed on a second side of the main magnetic pole in the track width direction from the main magnetic pole and is separated from the main magnetic pole by a second side gap;   a first layer that has a first magnetic relative permeability and is disposed in the write gap between the main magnetic pole and the write shield; and   a second layer that has a second magnetic relative permeability and is disposed in the first side gap and the second side gap, wherein   the first magnetic relative permeability is smaller than the second magnetic relative permeability,   the first layer includes a magnetic flux control layer in which a plurality of conductive layers are stacked, the magnetic flux control layer having a magnetic relative permeability smaller than that of air when a current flows through the magnetic flux control layer.   
     
     
         2 . The magnetic head according to  claim 1 , further comprising:
 a connection terminal that is configured to flow the current through the main magnetic pole, the magnetic flux control layer, and the write shield.   
     
     
         3 . The magnetic head according to  claim 1 , wherein
 the magnetic flux control layer includes a first control layer containing at least one element selected from the group consisting of Fe, Co, and Ni and a second control layer containing at least one element selected from the group consisting of Cu, Ag, and Au and stacked on the first control layer.   
     
     
         4 . The magnetic head according to  claim 1 , wherein
 the main magnetic pole and the write shield are electrically connected to each other via the magnetic flux control layer.   
     
     
         5 . A disk device comprising:
 a disk-shaped recording medium; and   a magnetic head comprising:   a main magnetic pole that generates a recording magnetic field;   a write shield disposed adjacent to the main magnetic pole and separated from the main magnetic pole by a write gap;   a first side shield that is disposed on a first side of the main magnetic pole in a track width direction from the main magnetic pole and is separated from the main magnetic pole by a first side gap;   a second side shield that is disposed on a second side of the main magnetic pole in the track width direction from the main magnetic pole and is separated from the main magnetic pole by a second side gap;   a first layer that has a first magnetic relative permeability and is disposed in the write gap between the main magnetic pole and the write shield; and   a second layer that has a second magnetic relative permeability and is disposed in the first side gap and the second side gap, wherein   the first magnetic relative permeability is smaller than the second magnetic relative permeability, and   the first layer includes a magnetic flux control layer in which a plurality of conductive layers are stacked, the magnetic flux control layer having a magnetic relative permeability smaller than that of air when a current flows through the magnetic flux control layer.   
     
     
         6 . The disk device according to  claim 5 , wherein
 the magnetic flux control layer includes a first control layer containing at least one element selected from the group consisting of Fe, Co, and Ni and a second control layer containing at least one element selected from the group consisting of Cu, Ag, and Au and stacked on the first control layer.   
     
     
         7 . The disk device according to  claim 5 , wherein
 the main magnetic pole and the write shield are electrically connected to each other via the magnetic flux control layer.