Methods for controlling stray fields of magnetic features using magneto-elastic anisotropy
Systems and methods for controlling stray fields of a magnetic feature are provided. One such method can involve selecting a plurality of materials for a magnetic feature, selecting a plurality of additives, combining the plurality of materials for the magnetic feature and the plurality of additives in an electrolyte solution to form a combined solution, adding nitrogen to the combined solution, degassing the combined solution, depositing the combined solution as a thin film on a wafer using pulse plating, and lapping the thin film to form an edge of the magnetic feature. In several embodiments, the magnetic feature is a component of a magnetic transducer such as a writer pole, a reader shield, or a writer shield.
1. A method for controlling stray fields of a magnetic feature, the method comprising:
determining a product of a magneto-striction and a tensile stress for candidate materials for a magnetic feature;
selecting a plurality of materials for the magnetic feature from the candidate materials such that the product of the magneto-striction and the tensile stress of the magnetic feature is a positive value;
selecting a plurality of additives;
combining the plurality of materials for the magnetic feature and the plurality of additives in an electrolyte solution to form a combined solution;
adding N to the combined solution;
degassing the combined solution;
depositing a thin film on a wafer from the combined solution using pulse plating to form the magnetic feature having the positive value; and
lapping the thin film to form an edge of the magnetic feature.
2. The method of claim 1 , wherein the magnetic feature is a component of a magnetic transducer selected from the group consisting of a writer pole, a reader shield, and a writer shield.
3. The method of claim 1 , wherein the selecting the plurality of materials for the magnetic feature from the candidate materials such that the product of the magneto-striction and the tensile stress of the magnetic feature is the positive value further comprises selecting a dopant and/or the plurality of additives such that the product of the magneto-striction and the tensile stress is the positive value.
4. The method of claim 3 , wherein the dopant is a material selected from the group consisting of S, O, H, N, C, and combinations thereof.
5. The method of claim 1 , wherein the plurality of additives comprise hydroxylmethyl-P-tolysulfone (HPT) in a concentration between about 0 to about 10 parts per million.
6. The method of claim 1 :
wherein the magnetic feature comprises a writer pole; and
wherein the plurality of materials for the magnetic feature comprise CoFe having an Fe content between about 50 and about 75 percent.
7. The method of claim 1 :
wherein the magnetic feature comprises a writer pole;
wherein the plurality of materials for the magnetic feature comprise CoFe with a preselected Fe content; and
wherein the selecting the plurality of additives comprises selecting the plurality of additives to achieve the preselected Fe content.
8. The method of claim 1 :
wherein the adding the N to the combined solution comprises adding the N to the combined solution to remove oxygen from the combined solution; and
wherein the degassing the combined solution comprises degassing the combined solution to remove oxygen and N from the combined solution.
9. The method of claim 1 , wherein the degassing the combined solution comprises applying a vacuum pressure to a membrane in contact with the combined solution.
10. The method of claim 1 :
wherein the magnetic feature comprises Fe; and
the method further comprising providing a sacrificial anode immersed in the combined solution to reverse oxidation of Fe 3+ present in the combined solution.
11. The method of claim 10 :
wherein the plurality of materials comprise Fe 2+ ; and
wherein the sacrificial anode comprises an active metal and is immersed in the combined solution to reverse oxidation of the Fe 3+ .
12. The method of claim 1 , wherein the magnetic feature comprises a writer pole.
13. The method of claim 12 :
wherein the selecting the plurality of materials for the magnetic feature from the candidate materials such that the product of the magneto-striction and the tensile stress of the magnetic feature is the positive value further comprises selecting a dopant and/or the plurality of additives such that the product of the magneto-striction and the tensile stress is the positive value; and
wherein the dopant is a material selected from the group consisting of S, O, H, N, C, and combinations thereof.
14. The method of claim 13 , wherein the plurality of additives comprise hydroxylmethyl-P-tolysulfone (HPT) in a concentration between about 0 to about 10 parts per million.
15. The method of claim 14 :
wherein the plurality of materials for the magnetic feature comprise CoFe having an Fe content between about 50 and about 75 percent.
16. The method of claim 15 , wherein the degassing the combined solution comprises applying a vacuum pressure to a membrane in contact with the combined solution.
17. The method of claim 16 :
the method further comprising providing a sacrificial anode immersed in the combined solution to reverse oxidation of Fe 3+ present in the combined solution.
18. The method of claim 17 :
wherein the plurality of materials comprise Fe 2+ ; and
wherein the sacrificial anode comprises an active metal and is immersed in the combined solution to reverse oxidation of the Fe 3+ .
19. The method of claim 1 :
wherein the selecting the plurality of materials for the magnetic feature from the candidate materials such that the product of the magneto-striction and the tensile stress of the magnetic feature is the positive value further comprises selecting a dopant and/or the plurality of additives such that the product of the magneto-striction and the tensile stress is the positive value; and
wherein the dopant comprises S, O, H, and N.
20. The method of claim 1 :
wherein the selecting, if the product is the positive value, the plurality of materials for the magnetic feature from the candidate materials further comprises selecting a dopant and/or the plurality of additives such that the product of the magneto-striction and the tensile stress is the positive value; and
wherein the dopant comprises S and H, wherein a concentration of H is greater than a concentration of S.