Shield Stabilization Configuration With Applied Bias

Abstract

An apparatus includes a sensor stack, first and second shields positioned on opposite sides of the sensor stack, and a first shield stabilization structure adjacent to the first shield and applying a bias magnetic field to the first shield. A second shield stabilization structure can be positioned adjacent to the second shield.

1 . An apparatus comprising:
 a sensor stack;   first and second shields positioned on opposite sides of the sensor stack; and   a first shield stabilization structure adjacent to the first shield and applying a bias magnetic field to the first shield.   
     
     
         2 . The apparatus of  claim 1 , wherein the first shield stabilization structure comprises:
 a first antiferromagnetic layer adjacent to a first magnetic layer.   
     
     
         3 . The apparatus of  claim 2 , further comprising:
 a second magnetic layer separated from the first magnetic layer by a first non-magnetic layer to form a first synthetic antiferromagnetic structure.   
     
     
         4 . The apparatus of  claim 3 , wherein magnetic moment between the first and second magnetic layers is balanced. 
     
     
         5 . The apparatus of  claim 1 , further comprising:
 a second shield stabilization structure adjacent to the second shield and applying a bias magnetic field to the second shield.   
     
     
         6 . The apparatus of  claim 5 , wherein the second shield stabilization structure comprises:
 a first antiferromagnetic adjacent to a first magnetic layer.   
     
     
         7 . The apparatus of  claim 6 , further comprising:
 a second magnetic layer separated from the first magnetic layer by a first non-magnetic layer to form a first synthetic antiferromagnetic structure.   
     
     
         8 . The apparatus of  claim 1 , wherein the first shield stabilization structure is positioned adjacent to a portion of the first shield. 
     
     
         9 . The apparatus of  claim 1 , wherein a width and depth of the first stabilization structure are greater than or equal to a width and depth of the sensor stack. 
     
     
         10 . The apparatus of  claim 9 , wherein the width of the first stabilization structure is greater than the depth of the first stabilization structure. 
     
     
         11 . An apparatus comprising:
 a sensor stack;   first and second shields positioned on opposite sides of the sensor stack; and   first and second magnetic layers positioned adjacent to the first shield and having balanced antiparallel magnetic moments.   
     
     
         12 . The apparatus of  claim 11 , further comprising:
 a first antiferromagnetic layer adjacent to a first magnetic layer.   
     
     
         13 . The apparatus of  claim 12 , further comprising:
 a first non-magnetic layer between the first and second magnetic layers.   
     
     
         14 . The apparatus of  claim 11 , further comprising:
 third and fourth magnetic layers positioned adjacent to the second shield and having balanced antiparallel magnetic moments.   
     
     
         15 . The apparatus of  claim 14 , further comprising:
 a second antiferromagnetic layer adjacent to a third magnetic layer.   
     
     
         16 . The apparatus of  claim 15 , further comprising:
 a second non-magnetic layer between the third and fourth magnetic layers.   
     
     
         17 . An apparatus comprising:
 a data storage medium;   a recording head including a sensor stack, first and second shields positioned on opposite sides of the sensor stack, and a first shield stabilization structure adjacent to the first shield and applying a bias magnetic field to the first shield; and   an arm for positioning the recording head adjacent to the data storage medium.   
     
     
         18 . The apparatus of  claim 17 , wherein the first shield stabilization structure comprises:
 a first antiferromagnetic adjacent to a first magnetic layer.   
     
     
         19 . The apparatus of  claim 18 , further comprising:
 a second magnetic layer separated from the first magnetic layer by a first non-magnetic layer to form a first synthetic antiferromagnetic structure.   
     
     
         20 . The apparatus of  claim 19 , wherein magnetic moment between the first and second magnetic layers is balanced. 
     
     
         21 . A method comprising:
 providing a sensor structure including a sensor stack, first and second shields positioned on opposite sides of the sensor stack, and a first shield stabilization structure adjacent to the first shield and applying a bias magnetic field to the first shield; and   annealing the structure at a first temperature lower than an anneal temperature of the sensor stack, to set a direction of magnetization of the first shield stabilization structure.   
     
     
         22 . The method of  claim 21 , wherein the first shield stabilization structure comprises a first antiferromagnetic layer adjacent to a first magnetic layer, and the first temperature is higher than an antiferromagnetic blocking temperature of the first antiferromagnetic layer. 
     
     
         23 . The method of  claim 21 , wherein the sensor structure includes a second shield stabilization structure adjacent to the second shield and applying a bias magnetic field to the second shield, the first shield stabilization structure comprises a first antiferromagnetic layer adjacent to a first magnetic layer, the second shield stabilization structure comprises a second antiferromagnetic layer adjacent to a second magnetic layer, and the first temperature is higher than an antiferromagnetic blocking temperature of the first and second antiferromagnetic layers.