Magnetoresistive element, preparation method thereof and sensing equipment

Abstract

The invention discloses a magnetoresistive element, a preparation method thereof and sensing equipment, and relates to the technical field of magnetic sensors. The magnetoresistive element comprises a plurality of magnetoresistive sub-elements; the magnetic resistance sub-element comprises a free layer, a pinned layer, a tunneling layer, a pinning layer and a regulation and control layer; the free layer has a variable magnetic field direction under an external magnetic field; the pinned layer has a fixed magnetization direction under an external magnetic field in a preset magnetic field range; the tunneling layer is arranged between the free layer and the pinned layer; the pinning layer is arranged on the side, away from the tunneling layer, of the pinned layer, the pinning layer and the pinned layer have exchange bias coupling, and the magnetization direction of the pinned layer is fixed through the exchange bias coupling; the regulation and control layer is arranged between the pinned layer and the tunneling layer and is used for generating spin current when preset current is introduced, so that the pinned layer and the pinned layer have exchange bias coupling. According to the invention, the pinning layer and the pinned layer can be induced to form exchange bias only by the spin current by using the spin orbit moment effect, so that the preparation efficiency of the magnetoresistive element is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic sensors, and in particular to a magnetoresistive element, a preparation method thereof, and a sensing device. Background Art

[0002] Magnetic sensors have important applications in many fields. Among them, TMR (Tunnel Magnetoresistance) sensors have high integration, high sensitivity, lower power consumption, and smaller temperature drift. Its basic working structural unit is MTJ (Magnetic Tunnel Junction).

[0003] In order to obtain good performance, the exchange bias of the reference layer (composed of a pinning layer and a pinned layer) of the TMR magnetic sensor needs to be fixed in a certain direction. Therefore, during the preparation process, it is necessary to reconstruct the exchange bias in the desired direction using a magnetic annealing furnace after preparing the functional multilayer film. As a result, the preparation efficiency of the magnetic sensor is very low.

[0004] Therefore, a new method of inducing exchange bias in magnetic sensors is urgently needed to solve the problem of complicated preparation steps of magnetic sensors. Summary of the invention

[0005] The main purpose of the present invention is to provide a magnetoresistive element and a preparation method and a sensing device thereof, aiming to solve the problem that the preparation steps of existing magnetic sensors are complicated.

[0006] To achieve the above-mentioned purpose, the magnetoresistive element proposed in the present invention includes a plurality of magnetoresistive sub-elements; the magnetoresistive sub-element includes a free layer, a pinned layer, a tunneling layer, a pinning layer and a regulating layer; the free layer has a variable magnetic field direction under an external magnetic field; the pinned layer has a fixed magnetization direction under an external magnetic field within a preset magnetic field range; the tunneling layer is arranged between the free layer and the pinned layer; the pinning layer is arranged on a side of the pinned layer away from the tunneling layer, and has exchange bias coupling with the pinned layer, and fixes the magnetization direction of the pinned layer through the exchange bias coupling; the regulating layer is arranged between the pinned layer and the tunneling layer, and is used to generate a spin current when a preset current is passed, so that the pinning layer and the pinned layer have exchange bias coupling.

[0007] In one embodiment, the free layer and the pinned layer are made of ferromagnetic materials; the pinned layer is made of antiferromagnetic materials; and the regulating layer is a two-dimensional material or a heavy metal material.

[0008] In one embodiment, the current density of the preset current is 1×10 9 Am -2 Up to 1×10 12 Am -2 .

[0009] In one embodiment, the material of the regulating layer is at least one of Pt, Ta and / or W.

[0010] In one embodiment, the current direction of the preset current and the magnetization direction of the pinned layer are both parallel to the plane where the pinned layer is located; the current direction of the preset current is perpendicular to the magnetization direction of the pinned layer.

[0011] In one embodiment, the current direction of the predetermined current is parallel to the easy magnetization direction of the pinned layer.

[0012] In one embodiment, the magnetoresistive element is provided with a first electrode and a second electrode; the first electrode is arranged on a side of the free layer away from the tunneling layer; the second electrode is arranged on a side of the pinned layer away from the pinned layer; a plurality of magnetoresistive elements are electrically coupled through the first electrode and / or the second electrode to form a Wheatstone bridge structure.

[0013] The present invention also provides a method for preparing a magnetoresistive element, and the method for preparing a magnetoresistive element comprises the following steps:

[0014] A bottom electrode layer and a plurality of magnetic stacks are sequentially formed on a substrate; the magnetic stacks at least include a free layer, a tunneling layer, a regulating layer, a pinned layer and a pinning layer;

[0015] Applying a current parallel to the film surface of the control layer to the control layer in the plurality of magnetic stacks, so that the pinned layers in the plurality of magnetic stacks have a fixed magnetization direction;

[0016] A top electrode layer is formed on each of the plurality of magnetic stacks to obtain a magnetoresistive element.

[0017] In one embodiment, the current density of the current applied to the regulating layer is 1×10 9 Am -2 Up to 1×10 12 Am -2 ; The current direction of the current applied to the regulation is parallel to the plane of the regulation layer and perpendicular to the magnetization direction of the pinned layer.

[0018] The present invention also provides a sensing device, which includes a magnetoresistive element; the magnetoresistive element is the above-mentioned magnetoresistive element, or a magnetoresistive element prepared by the above-mentioned method for preparing the magnetoresistive element; the magnetoresistive element can be used for measuring magnetic variables.

[0019] The technical solution of the present invention adopts a magnetoresistive element, which includes a plurality of magnetoresistive sub-elements; the magnetoresistive sub-elements include a free layer, a pinned layer, a tunneling layer, a pinning layer and a regulating layer; the free layer has a variable magnetic field direction under an external magnetic field; the pinned layer has a fixed magnetization direction under an external magnetic field within a preset magnetic field range; the tunneling layer is arranged between the free layer and the pinned layer; the pinning layer is arranged on a side of the pinned layer away from the tunneling layer, and has exchange bias coupling with the pinned layer, and fixes the magnetization direction of the pinned layer through the exchange bias coupling; the regulating layer is arranged between the pinned layer and the tunneling layer, and is used to generate a spin current when a preset current is passed, so that the pinning layer and the pinned layer have exchange bias coupling. The technical solution of the present invention is to provide a control layer in the magnetoresistive element, and to set the control layer between the tunnel layer and the pinned layer, so that when the current is applied to the control layer, a spin current can be generated according to the spin-orbit moment effect, thereby inducing exchange bias coupling between the pinned layer and the pinned layer, and further enabling the pinned layer to obtain a fixed magnetization direction. Compared with the traditional method of preparing magnetic sensors, which requires the use of a magnetic annealing furnace to achieve exchange bias coupling in the desired direction, the present solution only requires the introduction of a preset current to enable the control layer to generate a spin current, thereby inducing the pinned layer and the pinned layer to form an exchange bias coupling, thereby reducing the steps of control, simplifying the sensor preparation procedure, and improving the preparation efficiency of the magnetoresistive element. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0021] Figure 1 A schematic structural diagram of an embodiment of a magnetoresistive element provided by the present invention;

[0022] Figure 2 A schematic structural diagram of an embodiment of a magnetoresistive sub-element in a magnetoresistive element provided by the present invention;

[0023] Figure 3 A graph showing the easy-axis magnetoresistance curves of the pinned layer and the pinned layer without exchange bias induction of the magnetoresistance element of an embodiment of the present invention;

[0024] Figure 4 A graph showing the easy-axis magnetoresistance curves of the pinned layer and the pinned layer after exchange bias induction of a magnetoresistance element according to an embodiment of the present invention;

[0025] Figure 5A schematic diagram of the direction in which a preset current of an embodiment of a magnetoresistive element provided by the present invention induces exchange bias on a pinned layer of the magnetoresistive element.

[0026] Figure Number:

[0027] 1. Magnetoresistive element; 11. Free layer; 12. Pinned layer; 13. Tunneling layer; 14. Pinned layer; 15. Control layer; 2. First electrode; 3. Second electrode.

[0028] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0031] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or solutions that satisfy both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0032] Magnetic sensors have important applications in many fields. Among them, TMR (Tunnel Magnetoresistance) sensors have high integration, high sensitivity, lower power consumption, and smaller temperature drift. Its basic working structural unit is MTJ (Magnetic Tunnel Junction).

[0033] In order to obtain good performance, the exchange bias of the reference layer (composed of a pinning layer and a pinned layer) of the TMR magnetic sensor needs to be fixed in the direction of the magnetoresistance short axis. Therefore, during the preparation process, it is necessary to reconstruct the exchange bias in the desired direction using a magnetic annealing furnace after preparing the functional multilayer film. As a result, the preparation efficiency of the magnetic sensor is very low.

[0034] Therefore, a new method of inducing exchange bias in magnetic sensors is urgently needed to solve the problem of complicated preparation steps of magnetic sensors.

[0035] In order to solve the above problems, the present invention provides a magnetoresistive element.

[0036] See also Figure 1 and Figure 2 In one embodiment of the present invention, the magnetoresistive element includes a plurality of magnetoresistive sub-elements 1; the magnetoresistive sub-element 1 includes a free layer 11, a pinned layer 12, a tunneling layer 13, a pinning layer 14 and a regulating layer 15; the free layer 11 has a variable magnetic field direction under an external magnetic field; the pinned layer 12 has a fixed magnetization direction under an external magnetic field within a preset magnetic field range; the tunneling layer 13 is arranged between the free layer 11 and the pinned layer 12; the pinning layer 14 is arranged on a side of the pinned layer 12 away from the tunneling layer 13, and has exchange bias coupling with the pinned layer 12, and fixes the magnetization direction of the pinned layer 12 through the exchange bias coupling; the regulating layer 15 is arranged between the pinned layer 12 and the tunneling layer 13, and is used to generate a spin current when a preset current is passed, so that the pinning layer 14 has exchange bias coupling with the pinned layer 12.

[0037] It should be noted that the magnetoresistive element may be a TMR sensor, and the magnetoresistive sub-element 1 may be a MTJ (Magnetic Tunnel Junction). Figure 2 The I in the figure represents the current direction of the preset current.

[0038] The technical solution of the present invention is to provide a control layer 15 in the magnetoresistive element 1, and to arrange the control layer 15 between the tunneling layer 13 and the pinned layer 12, so that the control layer 15 can generate a spin current according to the spin-orbit moment effect when a current is applied, thereby inducing exchange bias coupling between the pinned layer 12 and the pinned layer 14, and further enabling the pinned layer 12 to obtain a fixed magnetization direction. Compared with the traditional method of preparing a magnetic sensor, which requires the use of a magnet to apply an external magnetic field or a magnetic annealing furnace to achieve exchange bias coupling in a desired direction, the present solution only requires the introduction of a preset current to enable the control layer 15 to generate a spin current, thereby inducing the pinned layer 14 to form an exchange bias coupling with the pinned layer 12. This purely electrical control method greatly simplifies the control steps of the magnetoresistive element 1 in the TMR magnetic sensor, shortens the preparation procedure of the magnetic sensor, and thus improves the preparation efficiency of the magnetoresistive element.

[0039] To illustrate the characteristics of the magnetoresistive element 1 before and after the exchange bias, see Figure 3 and Figure 4 , Figure 3 is the easy-axis magnetoresistance curve of the reference layer (i.e., the pinning layer 14 and the pinned layer 12) in the magnetoresistive element 1 that has not been subjected to exchange bias, and is represented by Figure 3 It can be seen that the magnetoresistance curves of the hard axis (H) and the easy axis (E) are symmetric about H=0Oe, which indicates that there is no exchange bias in the sample under the initial condition. Figure 4 In a zero magnetic field environment, a current pulse of a certain amplitude is passed along the two ends of the reference layer. The easy-axis magnetoresistance curve of the reference layer obtained after spin current regulation is given by Figure 4 It can be seen that the magnetoresistance curve in the easy axis direction is still symmetric about H=0Oe, while the magnetoresistance curve in the hard axis direction is symmetric about H=100Oe, indicating that after current pulse regulation, the reference layer forms an exchange bias field of about 100Oe along the hard axis direction.

[0040] In the embodiment of the present invention, the free layer 11 and the pinned layer 12 are made of ferromagnetic materials; the pinned layer 14 is made of antiferromagnetic materials; and the regulating layer 15 is a two-dimensional material or a heavy metal material.

[0041] Specifically, the free layer 11 and the pinned layer 12 are made of ferromagnetic materials, which can be NiFe, CoFe, etc., and their thickness can be set to 4nm to 20nm; the pinned layer 14 is made of antiferromagnetic materials, and the antiferromagnetic materials that can be used can be FeMn, IrMn, etc., and their thickness can be set to 5nm to 20nm; the control layer 15 is a two-dimensional material or a heavy metal material, which must have a spin Hall effect, that is, it can generate a spin-orbit torque (i.e., a spin current) when a current pulse is passed, so as to regulate the magnetization direction of the pinned layer 14 and the pinned layer 12.

[0042] Furthermore, in an embodiment of the present invention, the current density of the preset current is 1×10 9 Am -2 Up to 1×10 12 Am -2 The specific order of magnitude of the current density of the preset current depends on the thermal conductivity of the substrate, the film material and the ambient temperature during regulation. In actual operation, currents of different current densities can be used according to the above factors.

[0043] In an embodiment of the present invention, the material of the control layer 15 is a material having a spin-orbit effect. As an optional implementation, the material of the control layer 15 can be set to at least one of Pt, Ta and / or W; of course, other two-dimensional materials or heavy metal materials can also be used as the material of the control layer 15, as long as the material has a spin-orbit effect, and the material of the control layer 15 is not specifically limited here.

[0044] In addition, as an optional embodiment, the magnetoresistive element 1 may further include a covering layer, which is disposed on a side of the pinned layer 14 away from the free layer 11; the covering layer is used to improve the protection of the free layer 11, the pinned layer 12, the tunneling layer 13, the pinned layer 14 and the regulating layer 15. The covering layer may be made of a conductor material with good oxidation resistance and corrosion resistance, such as a conductor material such as Ta.

[0045] In the embodiment of the present invention, the current direction of the preset current and the magnetization direction of the pinned layer 12 are parallel to the plane where the pinned layer 12 is located; the current direction of the preset current is perpendicular to the magnetization direction of the pinned layer 12. It should be noted that the magnetization direction of the pinned layer 12 is usually fixed by generating a pinning effect on the pinned layer 12 through exchange bias coupling; specifically, the present invention passes a preset current into the control layer 15, so that the control layer 15 generates a spin current due to the spin Hall effect, and the spin current induces the pinned layer 12 and the pinning layer 14 to generate exchange bias coupling, thereby generating a pinning effect on the pinned layer 12, and then fixing the magnetization direction of the pinned layer 12.

[0046] In the embodiment of the present invention, the current direction of the preset current is parallel to the easy magnetization direction of the pinned layer 12. It should be noted that, different from the hard magnetization direction of the pinned layer 12, the easy magnetization direction of the pinned layer 12 is determined by the material properties of the pinned layer 12. In this embodiment, by making the current direction of the preset current parallel to the easy magnetization direction of the pinned layer 12, the current passed can use the spin-orbit effect to fix the exchange bias of the pinned layer 12 in the hard magnetization direction, so as to obtain the expected exchange bias coupling result.

[0047] Further, in the embodiment of the present invention, the first direction obtained after the current direction is rotated 90 degrees in the plane where the pinned layer 12 is located is parallel to the magnetization direction of the pinned layer 12. For ease of understanding, please refer to Figure 5 When the current direction I of the preset current used for regulation is passed from the left side, the magnetization direction X of the pinned layer 12 is fixed from the inside to the outside by the pinning effect; when the current direction I of the preset current used for regulation is passed from the right side, the magnetization direction X of the pinned layer 12 is fixed from the outside to the inside by the pinning effect.

[0048] In order to solve the conductive problem of the magnetoresistive element, in an embodiment of the present invention, the magnetoresistive element 1 is provided with a first electrode 2 and a second electrode 3; the first electrode 2 is arranged on the side of the free layer 11 away from the tunneling layer 13; the second electrode 3 is arranged on the side of the pinning layer 14 away from the pinned layer 12; and a plurality of magnetoresistive elements 1 are electrically coupled through the first electrode 2 and / or the second electrode 3 to form a Wheatstone bridge structure. In this way, the conductive effect of the magnetoresistive element 1 is achieved through the Wheatstone bridge structure formed between the plurality of magnetoresistive elements 1, and the Wheatstone bridge structure can greatly amplify a small resistance change. In a magnetic sensor such as a TMR magnetic sensor, when an external magnetic field changes the magnetization direction of the free layer 11, a small change in the resistance of the magnetoresistive element 1 will be caused, and the small change can be converted into a relatively large voltage output by the Wheatstone bridge structure, thereby improving the sensitivity of detection.

[0049] The present invention further provides a method for preparing a magnetoresistive element, the method for preparing a magnetoresistive element comprising steps S10 to S30:

[0050] Step S10, forming a bottom electrode layer and a plurality of magnetic stacks in sequence on a substrate; the magnetic stacks at least include a free layer, a tunneling layer, a regulating layer, a pinned layer and a pinning layer;

[0051] In step S10, it should be noted that the substrate can be set as a substrate made of a material such as a silicon wafer or glass; before using the substrate to form a bottom electrode layer and a plurality of magnetic stacks, the substrate can be pretreated to ensure the cleanliness of the substrate. The pretreatment operation can be performed by ultrasonically cleaning the substrate with acetone, alcohol, and deionized water for 5 minutes respectively, and then using pure nitrogen to blow dry the ultrasonically cleaned substrate; the specific pretreatment operation can be adjusted according to the cleaning degree requirements, and the pretreatment operation of the substrate is not limited here.

[0052] Step S20, applying a current parallel to the film surface of the regulating layer to the regulating layers in the plurality of magnetic stacks, so that the pinned layers in the plurality of magnetic stacks have a fixed magnetization direction;

[0053] In step S20, the magnetization direction of the pinned layer is fixed by applying a current to the control layer. Specifically, the control layer can be made of a material having a spin Hall effect, which can generate a spin current when a preset current is passed through it, so that the pinning layer and the pinned layer have exchange bias coupling, and the exchange bias coupling generates a pinning effect on the pinned layer, thereby fixing the magnetization direction of the pinned layer.

[0054] Step S30 , forming top electrode layers on the plurality of magnetic stacks respectively to obtain magnetoresistive elements.

[0055] In the preparation method of this embodiment, unlike the conventional preparation method of TMR magnetic sensors, this preparation method can induce the pinned layer and the pinning layer to generate exchange bias coupling by applying a current parallel to the film surface of the control layer to the control layer in multiple magnetic stacks, so that the pinned layers in the multiple magnetic stacks have a fixed magnetization direction. In this way, the preparation method can avoid the preparation steps of using a magnet as an auxiliary induction exchange bias in the conventional preparation method of TMR magnetic sensors, or using a magnetic annealing furnace to reconstruct the exchange bias in the desired direction, without the need to provide an additional magnetic field environment, greatly improving the growth efficiency of the TMR magnetic sensor, reducing the control steps, and simplifying the sensor preparation procedure.

[0056] In the embodiment of the present invention, the current density of the current applied to the regulating layer is 1×10 9 Am -2 Up to 1×10 12 Am -2 ; Among them, the specific order of magnitude of the current density of the current applied to the control layer depends on the thermal conductivity of the substrate, the film material and the ambient temperature during control. In actual operation, currents of different current densities can be used depending on the above factors.

[0057] In an embodiment of the present invention, the direction of the current applied to the regulation is parallel to the plane of the regulation layer and perpendicular to the magnetization direction of the pinned layer. Thus, according to the spin Hall effect, when the direction of the current is parallel to the plane of the regulation layer, the spin current generated by the regulation layer will be perpendicular to the direction of the current, so that the spin current can effectively interact with the adjacent pinned layer, so as to induce exchange bias coupling between the pinned layer and the pinning layer.

[0058] Further, as an optional implementation, step S10 may include steps S11 to S13:

[0059] Step S11, using mask lithography technology and magnetron sputtering technology to grow a bottom electrode layer on the substrate;

[0060] Step S12, using mask photolithography technology and ion etching technology, growing an oxide insulating thin layer on the front side of the substrate and etching a corresponding pattern of the magnetic stack, and connecting the corresponding pattern of the magnetic stack to the bottom electrode layer;

[0061] Step S13, based on the corresponding pattern of the magnetic stack, a free layer, a tunneling layer, a regulating layer, a pinned layer, and a pinning layer are grown in sequence from bottom to top on the front side of the substrate to form a magnetic stack.

[0062] In this embodiment, a specific implementation method of sequentially forming a bottom electrode layer and a plurality of magnetic stacks on a substrate is provided. Of course, other schemes may also be used to form the bottom electrode layer and the plurality of magnetic stacks, which is not limited here.

[0063] Further, as an optional implementation, step S30 may include steps S31 to S32:

[0064] Step S31, using a stripping process, covering the front surface of the substrate with a photoresist, and exposing and developing with a mask to obtain a corresponding pattern of the top electrode layer;

[0065] Step S32, based on the corresponding pattern of the top electrode layer, a top electrode layer is grown on the surface of the pinned layer using a thin film deposition technique, and excess electrode material film is ultrasonically cleaned using an organic solvent to finally obtain a magnetoresistive element.

[0066] In this embodiment, a specific implementation method of forming a top electrode layer respectively on a plurality of magnetic stacks is provided. Of course, other schemes may also be used to form the top electrode layer, which is not limited here.

[0067] The present invention also provides a sensing device, which includes a magnetoresistive element; the magnetoresistive element is the magnetoresistive element of the above embodiment, or a magnetoresistive element prepared by the method for preparing the magnetoresistive element of the above embodiment; the magnetoresistive element can be used to measure magnetic variables. The specific structure of the magnetoresistive element refers to the above embodiment. Since the sensing device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0068] The above description is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A magnetoresistive element, characterized in that: The magnetoresistive element comprises a plurality of magnetoresistive sub-elements; The magnetic resistance sub-element comprises: a free layer having a magnetic field direction that changes under an external magnetic field; A pinned layer having a fixed magnetization direction under an external magnetic field within a preset magnetic field range; a tunneling layer disposed between the free layer and the pinned layer; A pinning layer, which is disposed on a side of the pinned layer away from the tunneling layer, has an exchange bias coupling with the pinned layer, and fixes the magnetization direction of the pinned layer through the exchange bias coupling; The regulating layer is arranged between the pinned layer and the tunneling layer, and is used to generate a spin current when a preset current is passed, so that the pinning layer and the pinned layer have the exchange bias coupling.

2. The magnetoresistive element according to claim 1, wherein: The free layer and the pinned layer are made of ferromagnetic materials; The material of the pinning layer is antiferromagnetic material; The regulating layer is a two-dimensional material or a heavy metal material.

3. The magnetoresistive element according to claim 2, characterized in that The current density of the preset current is 1×10 9 Am -2 Up to 1×10 12 Am -2 .

4. The magnetoresistive element according to claim 2, wherein: The material of the regulating layer is at least one of Pt, Ta and / or W.

5. The magnetoresistive element according to claim 1, wherein: The current direction of the preset current and the magnetization direction of the pinned layer are both parallel to the plane where the pinned layer is located; The current direction of the preset current is perpendicular to the magnetization direction of the pinned layer.

6. The magnetoresistive element according to claim 5, characterized in that The current direction of the preset current is parallel to the easy magnetization direction of the pinned layer.

7. The magnetoresistive element according to claim 1, wherein: The magnetoresistive element is provided with a first electrode and a second electrode; The first electrode is disposed on a side of the free layer away from the tunneling layer; The second electrode is disposed on a side of the pinning layer away from the pinned layer; The plurality of magnetoresistive sub-elements are electrically coupled to each other through the first electrode and / or the second electrode to form a Wheatstone bridge structure.

8. A method for preparing a magnetoresistive element, characterized in that: The following steps are involved: A bottom electrode layer and a plurality of magnetic stacks are sequentially formed on a substrate; the magnetic stacks at least include a free layer, a tunneling layer, a regulating layer, a pinned layer and a pinning layer; Applying a current parallel to the film surface of the regulating layer to the regulating layer in the plurality of magnetic stacks, so that the pinned layers in the plurality of magnetic stacks have a fixed magnetization direction; A top electrode layer is formed on each of the plurality of magnetic stacks to obtain the magnetoresistive element.

9. The preparation method according to claim 8, characterized in that: The current density of the current applied to the control layer is 1×10 9 Am -2 Up to 1×10 12 Am -2 ; The direction of the current applied to the regulation is parallel to the plane of the regulation layer and perpendicular to the magnetization direction of the pinned layer.

10. A sensing device, characterized in that: including a magnetoresistive element; The magnetoresistive element is the magnetoresistive element according to any one of claims 1 to 7, or a magnetoresistive element prepared by the method for preparing a magnetoresistive element according to claim 8 or 9; The magnetoresistive element can be used for measuring magnetic variables.

Images