I claim:
1. In a magnetic read head having an air bearing surface (ABS), a magnetic tunnel junction (MTJ) sensor for connection to sense circuitry for detecting changes in electrical resistance within the sensor, the sensor comprising:
a MTJ stack with an active region disposed at the ABS and having two opposite sides each disposed generally orthogonally to the ABS, the MTJ stack comprising:
an antiferromagnetic (AFM) layer spanning the active region,
a pinned layer of ferromagnetic (FM) material in contact with the AFM layer,
a free layer of FM material spanning the active region and extending beyond each of the two opposite sides thereof, and
a tunnel junction layer of electrically nonconductive material disposed between the pinned layer and the free layer in the active region; and
a longitudinal bias layer formed on and in contact with the free layer outside of the active region for biasing the magnetic moment of the free layer in substantially a predetermined direction in the absence of an external magnetic field.
2. The sensor of claim 1 further comprising:
an insulating layer of electrically nonconductive material formed on and in contact with the free layer outside of the active region and in abutting contact with the two opposite sides of the active region.
3. The sensor of claim 2 wherein the longitudinal bias layer is disposed without contacting the active region.
4. The sensor of claim 3 wherein the longitudinal bias layer comprises a hard magnetic (HM) material.
5. The sensor of claim 3 wherein the longitudinal bias layer comprises an AFM material.
6. The sensor of claim 1 wherein the longitudinal bias layer is disposed without contacting the active region.
7. The sensor of claim 6 wherein the longitudinal bias layer comprises a HM material.
8. The sensor of claim 6 wherein the longitudinal bias layer comprises an AFM material.
9. The sensor of claim 1 further comprising:
the longitudinal bias layer comprises an electrically nonconductive AFM material disposed outside of the active region and in abutting contact with the two opposite sides of the active region.
10. The sensor of claim 1 wherein the longitudinal bias layer comprises an electrically nonconductive HM material disposed outside of the active region and in abutting contact with the two opposite sides of the active region.
11. A direct access storage device (DASD) comprising:
a magnetic recording disk having at least one surface for storing magnetically recorded data;
a magnetic read head having an air bearing surface (ABS) disposed for reading the data from the magnetic recording disk surface;
in the magnetic read head, a magnetic tunnel junction (MTJ) sensor comprising:
a MTJ stack with an active region disposed at the ABS and having two opposite sides each disposed generally orthogonally to the ABS, the MTJ stack comprising:
an antiferromagnetic (AFM) layer spanning the active region,
a pinned layer of ferromagnetic (FM) material in contact with the AFM layer,
a free layer of FM material spanning the active region and extending beyond each of the two opposite sides thereof, and
a tunnel junction layer of electrically nonconductive material disposed between the pinned layer and the free layer in the active region; and
a longitudinal bias layer formed on and in contact with the free layer outside of the active region for biasing the magnetic moment of the free layer in substantially a predetermined direction in the absence of an external magnetic field;
an actuator for moving the magnetic read head across the magnetic recording disk surface to access the data stored thereon; and
a data channel having sense circuitry coupled electrically to the MTJ sensor for detecting changes in resistance of the MTJ sensor caused by rotation of the magnetic moment of the free ferromagnetic layer relative to the fixed magnetic moment of the pinned layer responsive to magnetic fields representing the data stored on the magnet recording disk surface.
12. The DASD of claim 11 further comprising:
an insulating layer of electrically nonconductive material formed on and in contact with the free layer outside of the active region and in abutting contact with the two opposite sides of the active region.
13. The DASD of claim 12 wherein the longitudinal bias layer is disposed without contacting the active region.
14. The DASD of claim 13 wherein the longitudinal bias layer comprises a hard magnetic (HM) material.
15. The DASD of claim 13 wherein the longitudinal bias layer comprises an AFM material.
16. The DASD of claim 11 wherein the longitudinal bias layer is disposed without contacting the active region.
17. The DASD of claim 16 wherein the longitudinal bias layer comprises a HM material.
18. The DASD of claim 16 wherein the longitudinal bias layer comprises an AFM material.
19. The DASD of claim 11 further comprising:
the longitudinal bias layer comprises an electrically nonconductive AFM material disposed outside of the active region and in abutting contact with the two opposite sides of the active region.
20. The DASD of claim 11 wherein the longitudinal bias layer comprises an electrically nonconductive AFM material disposed outside of the active region and in abutting contact with the two opposite sides of the active region.
21. In a magnetic read head having an air bearing surface (ABS), a magnetic tunnel junction (MTJ) sensor for connection to sense circuitry for detecting changes in electrical resistance within the sensor, the sensor comprising:
a MTJ stack with an active region disposed at the ABS and having two opposite sides each disposed generally orthogonally to the ABS, the MTJ stack comprising:
an antiferromagnetic (AFM) layer spanning the active region,
a pinned layer of ferromagnetic (FM) material in contact with the AFM layer,
a free layer of FM material spanning the active region, and
a tunnel junction layer of electrically nonconductive material disposed between the pinned layer and the free layer in the active region; and
a nonconductive longitudinal bias layer formed outside of the active region and in abutting contact with the two opposite sides of the active region for biasing the magnetic moment of the free layer in substantially a predetermined direction in the absence of an external magnetic field.
22. The sensor of claim 21 wherein the nonconductive longitudinal bias layer comprises a hard magnetic (HM) material.
23. A direct access storage device (DASD) comprising:
a magnetic recording disk having at least one surface for storing magnetically recorded data;
a magnetic read head having an air bearing surface (ABS) disposed for reading the data from the magnetic recording disk surface;
in the magnetic read head, a magnetic tunnel junction (MTJ) sensor comprising:
a MTJ stack with an active region disposed at the ABS and having two opposite sides each disposed generally orthogonally to the ABS, the MTJ stack comprising:
an antiferromagnetic (AFM) layer spanning the active region,
a pinned layer of ferromagnetic (FM) material in contact with the AFM layer,
a free layer of FM material spanning the active region, and
a tunnel junction layer of electrically nonconductive material disposed between the pinned layer and the free layer in the active region; and
a nonconductive longitudinal bias layer formed outside of the active region and in abutting contact with the two opposite sides of the active region for biasing the magnetic moment of the free layer in substantially a predetermined direction in the absence of an external magnetic field;
an actuator for moving the magnetic read head across the magnetic recording disk surface to access the data stored thereon; and
a data channel having sense circuitry coupled electrically to the MTJ sensor for detecting changes in resistance of the MTJ sensor caused by rotation of the magnetic moment of the free ferromagnetic layer relative to the fixed magnetic moment of the pinned layer responsive to magnetic fields representing the data stored on the magnetic recording disk surface.
24. The sensor of claim 23 wherein the nonconductive longitudinal bias layer comprises a hard magnetic (HM) material.
25. A method for fabricating a magnetic tunnel junction (MTJ) sensor for use in a magnetic read head having an air bearing surface (ABS), the method comprising the unordered steps of:
(a) forming a MTJ stack with an active region disposed at the ABS and having two opposite sides each disposed generally orthogonally to the ABS, including the unordered steps of:
(a.1) forming an antiferromagnetic (AFM) layer,
(a.2) forming a pinned layer of ferromagnetic (FM) material in contact with the AFM layer,
(a.3) forming a free layer of FM material,
(a.4) forming a tunnel junction layer of electrically nonconductive material disposed between the pinned layer and the free layer, and
(a.5) removing all material outside of the active region from the AFM layer, the pinned layer, and the tunnel junction layer to define the two opposite sides of the active region; and
(b) forming a longitudinal bias layer outside of the active region in contact with the free layer for biasing the magnetic moment of the free layer in substantially a predetermined direction in the absence of an external magnetic field.
26. The method of claim 25 further comprising the step of:
(c) forming an insulating layer of electrically nonconductive material on and in contact with the free layer outside of the active region and in abutting contact with the two opposite sides of the active region.
27. The method of claim 26 wherein the longitudinal bias layer is disposed without contacting the active region.
28. The method of claim 27 wherein the longitudinal bias layer comprises a hard magnetic (HM) material.
29. The method of claim 27 wherein the longitudinal bias layer comprises an AFM material.
30. The method of claim 25 wherein the longitudinal bias layer is disposed without contacting the active region.
31. The method of claim 30 wherein the longitudinal bias layer comprises a HM material.
32. The method of claim 30 wherein the longitudinal bias layer comprises an AFM material.
33. The method of claim 25 wherein the forming step (b) further comprises the step of:
(b.1) forming a nonconductive longitudinal bias layer outside of the active region and in abutting contact with the two opposite sides of the active region for biasing the magnetic moment of the free layer in substantially a predetermined direction in the absence of an external magnetic field.
34. The sensor of claim 33 wherein the nonconductive longitudinal bias layer comprises a HM material.
35. The sensor of claim 33 wherein the nonconductive longitudinal bias layer comprises an AFM material.
36. The method of claim 25 wherein the removing step (a.5) further comprises the step of:
(a.5.1) removing all material outside of the active region from the AFM layer, the pinned layer, the tunnel junction layer and the free layer to define the two opposite sides of the active region.
37. The method of claim 36 wherein the forming step (b) further comprises the step of:
(b.1) depositing additional FM material on the free layer in the active region and beyond the two opposite sides of the active region.
38. The method of claim 37 further comprising the step of:
(c) forming an insulating layer of electrically nonconductive material on and in contact with the free layer outside of the active region and in abutting contact with the two opposite sides of the active region.
39. The method of claim 38 wherein the longitudinal bias layer is disposed without contacting the active region.
40. The method of claim 39 wherein the longitudinal bias layer comprises a hard magnetic (HM) material.
41. The method of claim 39 wherein the longitudinal bias layer comprises an AFM material.
42. The method of claim 37 wherein the longitudinal bias layer is disposed without contacting the active region.
43. The method of claim 42 wherein the longitudinal bias layer comprises a HM material.
44. The method of claim 42 wherein the longitudinal bias layer comprises an AFM material.
45. The method of claim 36 wherein the forming step (b) further comprises the step of:
(b.1) forming a nonconductive longitudinal bias layer outside of the active region and in abutting contact with the two opposite sides of the active region for biasing the magnetic moment of the free layer in substantially a predetermined direction in the absence of an external magnetic field.
46. The method of claim 45 wherein the nonconductive longitudinal bias layer comprises a hard magnetic (HM) material.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A system for performing waveform analysis on coagulation data comprising:
a coagulation analyzer configured to measure at least one of turbidity and optical density of a coagulation assay and to output the measured data; and
a waveform analysis tool coupled to the coagulation analyzer and configured to receive the measured data, the waveform analysis tool configured to analyze the measured data to determine a coagulation status of the coagulation assay not provided by the coagulation analyzer.
2. The system of claim 1 wherein the waveform analysis tool is configured to perform at least one of:
collecting multiple sets of measured coagulation data for multiple plasma samples;
plotting multiple sets of measured coagulation data for multiple plasma samples on one or more graphs; and
identifying slope, minima, maxima and area under curve for measured coagulation data.
3. The system of claim 1 wherein the waveform analysis tool is configured to perform at least one of:
diagnosing bleeding disorders based on measured coagulation data; and
screening for bleeding disorders based on measured coagulation data.
4. The system of claim 1 wherein the waveform analysis tool is configured to perform at least one of:
discriminating between different coagulation factor deficiencies based on measured coagulation data; and
discriminating between discrete levels of coagulation factors based on measured coagulation data.
5. The system of claim 1 wherein the waveform analysis tool is configured to perform diagnosing of treatment methods based on measured coagulation data.
6. The system of claim 1 wherein the waveform analysis tool is configured to perform at least one of:
discriminating between hemophiliac plasma, with and without inhibitors, and with or without therapeutic proteins used to treat hemophilia, based on measured coagulation data; and
discriminating between different activators of coagulation based on measured coagulation data.
7. The system of claim 1 wherein the waveform analysis tool is configured to perform at least one of:
monitoring effects of therapeutic agents based on measured coagulation data;
monitoring tailored or patient specific therapies based on measured coagulation data; and
monitoring therapeutic dosing based measured on coagulation data.
8. The system of claim 1 wherein the waveform analysis tool is configured to perform at least one of:
screening for new therapeutic compounds to treat coagulation blood disorders based on measured coagulation data;
screening for a dosage andor efficacy of new anticoagulants or procoagulants based on measured coagulation data; and
screening for efficacy of new anticoagulants or procoagulants based on measured coagulation data.
9. A method comprising:
obtaining a plasma sample from a patient;
performing a coagulation assay on the plasma sample;
measuring a coagulation property of the plasma sample using a coagulation analyzer so as to generate measured data;
performing waveform analysis on the measured data so as to obtain turbidity characteristics; and
employing the waveform analysis to determine a coagulation status of the coagulation assay not provided by the coagulation analyzer.
10. The method of claim 9, wherein the coagulation assay includes one or more of an activated partial thromboplastin time (\u201caPTT\u201d) assay, a prothrombin time (\u201cPT\u201d) assay, a dilute prothrombin (\u201cdPT\u201d) assay, and a factor specific coagulation assay.
11. The method of claim 9, wherein the measured coagulation property includes turbidity.
12. The method of claim 9, wherein the measured coagulation property includes optical density.
13. The method of claim 9, wherein performing waveform analysis includes at least one of:
collecting multiple sets of measured coagulation data for multiple plasma samples;
plotting multiple sets of measured coagulation data for multiple plasma samples on one or more graphs; and
identifying slope, minima, maxima and area under curve for measured coagulation data.
14. The method of claim 9, wherein employing the waveform analysis to determine a coagulation status of the coagulation assay includes at least one of:
diagnosing bleeding disorders based on measured coagulation data; and
screening for bleeding disorders based on measured coagulation data.
15. The method of claim 9, wherein employing the waveform analysis to determine a coagulation status of the coagulation assay includes at least one of:
discriminating between different coagulation factor deficiencies based on measured coagulation data; and
discriminating between discrete levels of coagulation factors based on measured coagulation data,
16. The method of claim 9, wherein employing the waveform analysis to determine a coagulation status of the coagulation assay includes diagnosing treatment methods based on measured coagulation data.
17. The method of claim 9, wherein employing the waveform analysis to determine a coagulation status of the coagulation assay includes at least one of:
discriminating between hemophiliac plasma, with and without inhibitors, and with or without therapeutic proteins used to treat hemophilia, based on measured coagulation data; and
discriminating between different activators of coagulation based on measured coagulation data.
18. The method of claim 9, wherein employing the waveform analysis to determine a coagulation status of the coagulation assay includes at least one of:
monitoring effects of therapeutic agents based on measured coagulation data;
monitoring tailored or patient specific therapies based on measured coagulation data; and
monitoring therapeutic dosing based measured on coagulation data.
19. The method of claim 9, wherein employing the waveform analysis to determine a coagulation status of the coagulation assay includes at least one of:
screening for new therapeutic compounds to treat a coagulation blood disorder based on measured coagulation data;
screening for a dosage andor efficacy of new anticoagulants or procoagulants based on measured coagulation data; and
screening for efficacy of new anticoagulants or procoagulants based on measured coagulation data.
20. The method of claim 9, wherein employing the waveform analysis to determine a coagulation status of the coagulation assay includes comparing the coagulation status of plasma samples from patients with the same condition.