Method for AFC shields for multiple sensor magnetic transducers and magnetic transducers having multiple sensors and AFC shields
View Patent ↗A method and system provide a magnetic transducer having an air-bearing surface (ABS). The method includes providing a first shield, a first read sensor, an antiferromagnetically coupled (AFC) shield that includes an antiferromagnet, a second read sensor and a second shield. The read sensors are between the first and second shields. The AFC shield is between the read sensors. An optional anneal for the first shield is in a magnetic field at a first angle from the ABS. Anneals for the first and second read sensors are in magnetic fields in desired first and second read sensor bias directions. The AFC shield anneal is in a magnetic field at a third angle from the ABS. The second shield anneal is in a magnetic field at a fifth angle from the ABS. The fifth angle is selected based on a thickness and a desired AFC shield bias direction for the antiferromagnet.
1. A method for providing a magnetic read transducer having an air-bearing surface (ABS) location, the method comprising:
providing a first shield;
providing a first read sensor residing in a down track direction from the first shield;
providing an antiferromagnetically coupled (AFC) shield residing in the down track direction from the first read sensor, wherein the AFC shield includes a first plurality of ferromagnetic layers interleaved with at least a first nonmagnetic spacer layer and a first antiferromagnet, wherein the first antiferromagnet adjoins one of the first plurality of ferromagnetic layers;
providing a second read sensor, wherein the AFC shield resides between the first read sensor and the second read sensor;
providing a second shield, wherein the second shield includes at least one ferromagnetic layer;
annealing at least the AFC shield in a magnetic field at an angle from the ABS location, wherein the angle is selected based on a thickness of the antiferromagnet and a desired AFC shield bias direction, the annealing resulting in the AFC shield being biased in the desired AFC shield bias direction, wherein the desired AFC shield bias direction is in a direction at least zero degrees and not more than forty-five degrees from the ABS location;
providing an additional AFC shield residing in the down track direction from the second read sensor, wherein the second read sensor is between the AFC shield and the additional AFC shield, wherein the additional AFC shield includes a second plurality of ferromagnetic layers interleaved with at least a second nonmagnetic spacer layer and a second antiferromagnet, wherein providing the additional AFC shield includes annealing the additional AFC shield, the second read sensor, the AFC shield, the first read sensor and the first shield in an additional magnetic field having an additional direction at an additional angle from the ABS location; and
providing a third read sensor residing in the down track direction from the additional AFC shield, wherein the additional AFC shield is between the second read sensor and the third read sensor, wherein the third read sensor is between the additional AFC shield and the second shield, wherein providing the third read sensor includes annealing the first shield, the first read sensor, the AFC shield, the second read sensor, the additional AFC shield and the third read sensor in another magnetic field having another direction at a second additional angle from the ABS location, wherein the other direction is a desired third read sensor bias direction.
2. The method of claim 1 wherein providing the AFC shield further includes:
providing a CoFeB insertion layer in at least one ferromagnetic layer of the first plurality of ferromagnetic layers.
3. The method of claim 2 wherein providing the AFC shield further includes:
configuring the at least the first nonmagnetic layer to have a thickness corresponding to a first antiferromagnetic peak or a second antiferromagnetic peak in a Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between the first plurality of ferromagnetic layers.
4. The method of claim 3 wherein configuring the at least the first nonmagnetic layer such that the thickness is within the second antiferromagnetic peak in the RKKY interaction.
5. The method of claim 4 wherein providing the second shield further includes:
providing an additional AFC shield of the second shield, the additional AFC shield of the second shield including a second plurality of ferromagnetic layers of the second shield interleaved with at least a second nonmagnetic spacer layer of the second shield and a second antiferromagnet of the second shield.
6. The method of claim 5 wherein providing the additional AFC shield further includes:
providing an additional CoFeB insertion layer in at least a ferromagnetic layer of the second plurality of ferromagnetic layers.
7. The method of claim 6 wherein providing the additional AFC shield further includes:
configuring the at least the second nonmagnetic layer to have an additional thickness corresponding to the first antiferromagnetic peak or the second antiferromagnetic peak in the RKKY interaction between the second plurality of ferromagnetic layers.