Coupled soft bias scissor type sensor

#In recent years, the read heads of magnetoresistive devices and recording bits on magnetic recording media have become progressively smaller, and as a result, the recording density of stored data has increased. Smaller recording bits generate smaller magnetic flux and smaller output signals, which increase the sensitivity requirements of the read head. A scissor type sensor, which has two free ferromagnetic layers being coupled in anti-parallel directions relative to each other, has been proposed to further improve the sensitivity of the read head. One difficulty encountered is that when various stresses, including external magnetic fields and heat, are applied to read heads with scissor type sensors, bias magnetization reversal often occurs and causes hysteresis in the transfer curve. These complications have limited the practical application of scissor type sensors in conventional magnetoresistive devices.

#The present disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings, in which the like reference numerals indicate like elements and in which:

#FIG. 1 illustrates an exemplary magnetic disk drive, according to one disclosed embodiment;

#FIG. 2 is a schematic partial cross-sectional view through the middle section of a magnetic read head according to an embodiment of the invention;

#A selected embodiment of the present invention will now be described with reference to the accompanying drawings. It will be apparent to those skilled in the art from this disclosure that the following description of an embodiment of the invention is provided for illustration only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

#The present disclosure is directed to a TMR (tunnel junction magnetoresistive) and CPP-GMR (current perpendicular to plane giant magnetoresistive) read head, an embodiment of which is shown beginning in FIG. 2, for a magnetic recording system such as a disk drive as shown in FIG. 1.

#Turning initially to FIG. 1, this Figure illustrates a top view of an exemplary hard disk drive (HDD) 1, according to an embodiment of the disclosure. HDD 1 is coupled to an associated host computing system 2, and is used to store information used by the computing system during processing. As illustrated, HDD 1 may include one or more perpendicular magnetic recording media 3, actuators 4, actuator arms 5, and suspension arms 6 associated with each of the perpendicular magnetic recording media 3, and a spindle motor 7 affixed in a chassis 8. The perpendicular magnetic recording media 3 may be arranged in a vertical stack, if more than one is provided. Moreover, the one or more perpendicular magnetic recording media 3 may be coupled with the spindle motor 7 for rotation in a rotation direction R.