Spin-torque oscillator for microwave assisted magnetic recording
View Patent ↗A microwave assisted magnetic recording write head having a spin torque oscillator capable of producing high strength high frequency magnetic oscillations with reduced applied current. The spin torque oscillator uses a magnetic field generation layer with a high moment material including such as Fe and Co that is formed on an interlayer having a face centered cubic (fcc) crystal structure, that functions as an under-layer. The high moment magnetic field generation layer has also reduced magnetic damping.
1. A magnetic write head for magnetic data recording, comprising:
a magnetic write pole; and
a spin torque oscillator located adjacent to the magnetic write pole, the spin torque oscillator further comprising:
a magnetic spin injection layer, comprising Co—Fe—B;
a magnetic field generation layer comprising an alloy containing one or more of Fe and Co and having a body centered cubic crystalline structure;
a first non-magnetic interlayer disposed between the magnetic spin injection layer and the magnetic field generation layer; and
a second interlayer disposed adjacent to the magnetic field generation layer, the second interlayer comprising a non-magnetic material having a face centered cubic crystal structure, the magnetic field generation layer having the body centered cubic crystalline structure being formed on the second interlayer having the face centered cubic crystalline structure.
2. The magnetic write head as in claim 1 wherein the magnetic field generation layer comprises Co—Fe having a Fe content of 25 to 100 atomic percent.
3. The magnetic write head as in claim 1 wherein the magnetic field generation layer is a multi-layered structure.
4. The magnetic write head as in claim 1 wherein the magnetic field generation layer comprises a Heusler alloy.
5. The magnetic write head as in claim 4 wherein the magnetic field generation layer comprises one or more of CoFeGe, CoFeAl and CoFeSi.
6. The magnetic write head as in claim 1 wherein the spin injection layer further comprises one or more of Co—Pt, Co—Cr—Pt, CoPd, Fe—Pt, Co—Fe—Pd or Tb—Fe—Co.
7. The magnetic write head as in claim 1 wherein the spin injection layer comprises a multi-layered structure further comprising Co and Pt, Co and Pd, or Co and Ni.
8. The magnetic write head as in claim 1 wherein the spin injection layer further comprises a Heusler alloy.
9. The magnetic write head as in claim 1 wherein the magnetic field generation layer is located between the write pole and the first interlayer and spin injection layer, and wherein the second interlayer is located between the magnetic field generation layer and the write pole.
10. The magnetic write head as in claim 1 wherein the magnetic field generation layer is located between the write pole and the first interlayer, and wherein the second interlayer is located between the magnetic field generation layer and the write pole, and wherein the spin injection layer is located between the first interlayer and a trailing magnetic shield.
11. The magnetic write head as in claim 1 wherein the spin injection layer is located between the write pole and the first interlayer, and wherein the magnetic field generation layer is located between the first interlayer and a trailing magnetic shield, and wherein the second interlayer is located between the magnetic field generation layer and the trailing magnetic shield.
12. The magnetic write head as in claim 10 wherein the magnetic field generation layer has been thermally treated to change its crystal structure.
13. The magnetic write head as in claim 1 wherein the magnetic field generation layer comprises a magnetic material having a body centered cubic structure.
14. The magnetic write head as in claim 1 , wherein the second interlayer comprises one or more of Pt, Ir, or Ni—Fe.
15. A magnetic data recording system, comprising:
a housing;
a magnetic media mounted within the housing
a slider;
an actuator connected with the slider for moving the slider adjacent to a surface of the magnetic media; and
a write head formed on the slider, the write head further comprising:
a magnetic write pole; and
a spin torque oscillator located adjacent to the magnetic write pole, the spin torque oscillator further comprising:
a magnetic spin injection layer comprising Co—Fe—B;
a magnetic field generation layer comprising an alloy containing one or more of Fe and Co and having a body centered cubic crystalline structure;
a first non-magnetic interlayer disposed between the magnetic spin injection layer and the magnetic field generation layer; and
a second interlayer disposed adjacent to the magnetic field generation layer, the second interlayer comprising a non-magnetic material having a face centered cubic crystal structure, the magnetic field generation layer having the body centered cubic crystalline structure being formed on the second interlayer having the face centered cubic crystalline structure.
16. The magnetic data recording system as in claim 15 wherein the magnetic field generation layer comprises a magnetic material having a body centered cubic crystal structure.
17. The magnetic data recording system as in claim 15 wherein the magnetic field generation layer comprises Co—Fe having a Fe content of 25 to 100 atomic percent.
18. The magnetic data recording system as in claim 15 wherein the magnetic field generation layer comprises a Heusler alloy.
19. The magnetic data recording system as in claim 15 wherein the magnetic field generation layer is a multi-layered structure.
20. The magnetic data recording system as in claim 15 , wherein the second interlayer comprises one or more of Pt, Ir, or Ni—Fe.