阅读说明：本技术 一种磁隧道结微拉力探测器 (Magnetic tunnel junction micro-tension detector ) 是由 于孟今 于 2021-09-02 设计创作，主要内容包括：本发明涉及拉力探测领域,具体提供了一种磁隧道结微拉力探测器,反铁磁部的材料为硬磁反铁磁材料,钉扎部置于反铁磁部上,钉扎部的材料为自旋性极化率高的金属或半金属,势垒部置于钉扎部上,自由层部置于势垒部上的中部,第一施力部和第二施力部固定在势垒部上的两端。在本发明中,钉扎部、势垒部、自由层部形成磁隧道结。应用时,待测拉力作用到第一施力部和第二施力部,同时应用磁场作用于本发明。通过测量施加微拉力时和未施加微拉力时,磁隧道结的磁电阻的差异,确定待测微拉力。本发明具有微拉力探测灵敏度高的优点。(The invention relates to the field of tension detection, and particularly provides a magnetic tunnel junction micro-tension detector. In the present invention, the pinned portion, the barrier portion, and the free layer portion form a magnetic tunnel junction. When the device is used, the tensile force to be measured acts on the first force application part and the second force application part, and meanwhile, the magnetic field acts on the device. And determining the micro-pulling force to be measured by measuring the difference of the magnetoresistance of the magnetic tunnel junction when the micro-pulling force is applied and when the micro-pulling force is not applied. The invention has the advantage of high micro-pulling force detection sensitivity.)

1. The magnetic tunnel junction micro-pulling force detector is characterized by comprising an antiferromagnetic part, a pinning part, a potential barrier part, a free layer part, a first force application part and a second force application part, wherein the antiferromagnetic part is made of hard magnetic antiferromagnetic materials, the pinning part is arranged on the antiferromagnetic part, the pinning part is made of metals or semimetals with high spin polarizability, the potential barrier part is arranged on the pinning part, the free layer part is arranged in the middle of the potential barrier part, the free layer part is made of soft magnetic materials with weak magnetic anisotropy, and the first force application part and the second force application part are fixed at two ends of the potential barrier part.

2. The magnetic tunnel junction micro-tensile detector of claim 1, wherein: the first force application part and the second force application part are fixedly connected with two opposite side surfaces of the free layer part respectively.

3. The magnetic tunnel junction micro-tensile detector of claim 2, wherein: still include first elastic component and second elastic component, first elastic component with the second elastic component sets up on the antiferromagnetic portion pinning portion's relative both sides, the barrier portion is arranged in first elastic component pinning portion on the second elastic component, first application of force portion with second application of force portion fixes respectively on the barrier portion the upside of first elastic component with the second elastic component.

4. The magnetic tunnel junction micro-tensile detector of claim 3, wherein: the first and second elastic parts have the same height as the pinning part.

5. The magnetic tunnel junction micro-tensile detector of claim 4, wherein: the first elastic part and the second elastic part are made of elastic insulating materials.

6. The magnetic tunnel junction micro-tensile detector of claim 5, wherein: the barrier portion is thin below the free layer portion; the barrier portion is thick outside the free layer portion.

7. The magnetic tunnel junction micro pull detector of any of claims 1-6, wherein: the material of the barrier portion is aluminum oxide or magnesium oxide.

8. The magnetic tunnel junction micro-tensile detector of claim 7, wherein: the material of the free layer part is NiFe alloy, CoFe alloy and CoFeB alloy.

9. The magnetic tunnel junction micro-tensile detector of claim 8, wherein: the pinning part is made of Co, Fe, CoFe, CoFeB and CoFeAl alloy.

10. The magnetic tunnel junction micro pull detector of claim 9, wherein: the material of the antiferromagnetic part is IrMn, PtMn and FeMn.

Technical Field

The invention relates to the field of tension detection, in particular to a magnetic tunnel junction micro-tension detector.

Background

The tension detection belongs to basic physical quantity detection. The tension detection not only has important application in the fields of industrial processes, household appliances, aerospace, automatic control and the like, but also has important application in scientific research on researching the relationship between material characteristics and stress and the like under extreme conditions, such as low-temperature environment. The traditional tension detector based on capacitance change or resistance change has low sensitivity and cannot meet the requirement of micro tension detection.

Disclosure of Invention

In order to solve the above problems, the present invention provides a magnetic tunnel junction micro-tensile detector, which includes an antiferromagnetic portion, a pinned portion, a barrier portion, a free layer portion, a first force application portion, and a second force application portion, wherein the antiferromagnetic portion is made of a hard magnetic antiferromagnetic material, the pinned portion is disposed on the antiferromagnetic portion, the pinned portion is made of a metal or a semimetal having a high spin polarizability, the barrier portion is disposed on the pinned portion, the free layer portion is disposed in the middle of the barrier portion, the free layer portion is made of a soft magnetic material having a weak magnetic anisotropy, and the first force application portion and the second force application portion are fixed at two ends of the barrier portion.

Furthermore, the first force application part and the second force application part are respectively and fixedly connected with two opposite side surfaces of the free layer part.

Still further, still include first elastic component and second elastic component, first elastic component and second elastic component set up the relative both sides of pinning the portion on the antiferromagnetic portion, and the barrier portion is arranged in on first elastic component, pinning portion, the second elastic component, and first application of force portion and second application of force portion are fixed respectively on the barrier portion the upside of first elastic component and second elastic component.

Further, the first and second elastic parts have the same height as the pinning parts.

Further, the first elastic part and the second elastic part are made of elastic insulating materials.

Further, under the free layer portion, the barrier portion is thin; the barrier portion is thick outside the free layer portion.

Further, the material of the barrier portion is aluminum oxide or magnesium oxide.

Furthermore, the material of the free layer part is NiFe alloy, CoFe alloy and CoFeB alloy.

Further, the material of the pinning portion is Co, Fe, CoFe, CoFeB, CoFeAl alloy.

Further, the material of the antiferromagnetic part is IrMn, PtMn, FeMn.

The invention has the beneficial effects that: the invention provides a magnetic tunnel junction micro-pulling force detector which comprises an antiferromagnetic part, a pinning part, a potential barrier part, a free layer part, a first force application part and a second force application part, wherein the antiferromagnetic part is made of hard magnetic antiferromagnetic materials, the pinning part is arranged on the antiferromagnetic part, the pinning part is made of metals or semimetals with high spin polarizability, the potential barrier part is arranged on the pinning part, the free layer part is arranged in the middle of the potential barrier part, and the first force application part and the second force application part are fixed at two ends of the potential barrier part. In the present invention, the pinned portion, the barrier portion, and the free layer portion form a magnetic tunnel junction. When the device is used, the tensile force to be measured acts on the first force application part and the second force application part, and meanwhile, the magnetic field acts on the device. The first force application part and the second force application part change the stress in the barrier part, and the micro-pulling force to be measured is determined by measuring the difference of the magnetoresistance of the magnetic tunnel junction when the micro-pulling force is applied and when the micro-pulling force is not applied. In the invention, the micro-pulling force to be measured changes the stress in the potential barrier part, thereby changing the quantum tunneling characteristic of the potential barrier part and further changing the magnetoresistance of the magnetic tunnel junction. The magnetoresistance of the magnetic tunnel junction depends heavily on the stress in the barrier part, so the invention has the advantage of high micro-pulling force detection sensitivity.

The present invention will be described in further detail below with reference to the accompanying drawings.

Drawings

FIG. 1 is a schematic diagram of a magnetic tunnel junction micro-tensile detector.

FIG. 2 is a schematic diagram of yet another magnetic tunnel junction micro-tensile detector.

In the figure: 1. an antiferromagnetic portion; 2. a pinning portion; 3. a potential barrier section; 4. a free layer portion; 5. a first force application part; 6. a second force application part; 7. a first elastic part; 8. a second elastic part.

Detailed Description

The technical scheme of the invention is further explained by combining the attached drawings.

Example 1

The invention provides a magnetic tunnel junction micro-pulling force detector, which comprises an antiferromagnetic part 1, a pinning part 2, a barrier part 3, a free layer part 4, a first force application part 5 and a second force application part 6, as shown in figure 1. The material of the antiferromagnetic portion 1 is a hard magnetic antiferromagnetic material, specifically, the material of the antiferromagnetic portion 1 is IrMn, PtMn, FeMn. The pinning portion 2 is disposed on the antiferromagnetic portion 1. The material of the pinning region 2 is a metal or semimetal having a high spin polarizability, and specifically, the material of the pinning region 2 is Co, Fe, CoFe, CoFeB, or CoFeAl alloy. The barrier portion 3 is placed on the pinning portion 2. The material of the barrier portion 3 is aluminum oxide or magnesium oxide. The free layer portion 4 is disposed in the middle on the barrier portion 3. The material of the free layer portion 4 is a soft magnetic material having weak magnetic anisotropy, and specifically, the material of the free layer portion 4 is a NiFe alloy, a CoFe alloy, or a CoFeB alloy. The first biasing portion 5 and the second biasing portion 6 are fixed to both ends of the barrier portion 3. The first force application part 5 and the second force application part 6 are made of insulating materials. The material of the first force application portion 5 and the second force application portion 6 is not limited herein.

In the present invention, the pinned portion 2, the barrier portion 3, and the free layer portion 4 form a magnetic tunnel junction. When the device is used, the tensile force to be measured acts on the first force application part 5 and the second force application part 6, and meanwhile, a magnetic field acts on the device. The first force application portion 5 and the second force application portion 6 change the stress in the barrier portion 3. And determining the micro-pulling force to be measured by measuring the difference of the magnetoresistance of the magnetic tunnel junction when the micro-pulling force is applied and when the micro-pulling force is not applied. In the invention, the micro-pulling force to be measured changes the stress in the potential barrier part 3, thereby changing the quantum tunneling characteristic of the potential barrier part 3 and further changing the magnetoresistance of the magnetic tunnel junction. The magnetoresistance of the magnetic tunnel junction depends heavily on the stress in the barrier portion 3, so the invention has the advantage of high detection sensitivity of micro-pulling force.

In addition, in the present invention, the micro-pulling force changes not only the stress within the barrier portion 3 but also the interface between the barrier portion 3 and the free layer portion 4, thereby changing the quantum tunneling characteristic of the interface between the barrier portion 3 and the free layer portion 4. Therefore, the invention can realize the detection of the micro-pulling force with higher sensitivity.

Example 2

In example 1, the first biasing member 5 and the second biasing member 6 are fixedly connected to the opposite side surfaces of the free layer portion 4. That is, the free layer portion 4 is fixedly connected to the first biasing portion 5 and the second biasing portion 6, in addition to the first biasing portion 5 and the second biasing portion 6 being fixed to the barrier portion 3. Thus, the micro-pulling force not only changes the stress in the barrier portion 3, but also changes the stress in the free layer portion 4, thereby not only changing the quantum tunneling characteristic of the barrier portion 3, but also changing the spin state in the free layer portion 4, thereby further changing the magnetoresistance of the magnetic tunnel junction, and realizing the micro-pulling force detection with higher sensitivity.

Example 3

In addition to embodiment 1, as shown in fig. 2, the magnetic resonance imaging apparatus further includes a first elastic portion 7 and a second elastic portion 8, the first elastic portion 7 and the second elastic portion 8 are disposed on the antiferromagnetic portion 1 on opposite sides of the pinning portion 2, the barrier portion 3 is disposed on the first elastic portion 7, the pinning portion 2, and the second elastic portion 8, and the first force application portion 5 and the second force application portion 6 are respectively fixed on the barrier portion 3 on upper sides of the first elastic portion 7 and the second elastic portion 8. The first elastic portion 7 and the second elastic portion 8 have the same height as the pinning portion 2. The first elastic portion 7 and the second elastic portion 8 are elastic insulating materials. The material of the first elastic part 7 and the second elastic part 8 may be elastic fiber or rubber. Thus, the contact area of the pinning portion 2 with the barrier portion 3 is reduced, and the restriction action of the pinning portion 2 with respect to the barrier portion 3 when the barrier portion 3 is elongated is reduced. When the micro-pulling force to be detected acts on the first force application part 5 and the second force application part 6, the potential barrier part 3 can deform more, so that the quantum tunneling characteristic of the potential barrier part 3 is changed more, and the micro-pulling force detection with higher sensitivity is realized. In addition, because the first elastic part 7 and the second elastic part 8 have elasticity, when the micro-pulling force is not along the horizontal direction in fig. 2, the micro-pulling force also causes the first elastic part 7 or the second elastic part 8 to deform in the vertical direction in fig. 2, so as to drive the barrier part 3 to bend, so that more stress is generated in the barrier part 3, and thus the quantum tunneling characteristics of the barrier part 3 are changed more, so as to realize the detection of the fine characteristics of the micro-pulling force.

Further, under the free layer portion 4, the barrier portion 3 is thin; the barrier portion 3 is thick outside the free layer portion 4. Thus, on the one hand, the first biasing member 5 and the second biasing member 6 can be more stably fixed to the barrier portion 3; on the other hand, at the lower side of the free layer portion 4, electrons can quantum tunnel more through the barrier portion 3. When the micro-pulling force to be measured is applied to the first force application part 5 and the second force application part 6, the number of electrons passing through the barrier part 3 changes more, thereby realizing a micro-pulling force detection with higher sensitivity.

Example 4

On the basis of embodiment 3, the top surface of the barrier portion 3 has a rough projection. The shape of the asperities is not limited herein. The adjacent rough protrusions are not connected with each other. Preferably, the distance between adjacent asperities is less than 40 nanometers in order to produce strong electric field coupling. Thus, under the action of the first force application part 5 and the second force application part 6, not only the stress inside the barrier part 3 is changed, but also the distance between the rough protrusions on the top surface of the barrier part 3 is changed, so that the local electric field between the rough protrusions is changed, the quantum tunneling characteristics of the barrier part 3 are changed more, and the micro-pulling force detection with higher sensitivity is realized.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the protection scope of the present invention. All equivalent changes and modifications made according to the spirit of the present invention should be covered within the protection scope of the present invention.