Preparation method for improving non-traditional spin-orbit torque efficiency by regulating and controlling Mn3Sn crystal face and application

Abstract

The invention belongs to the technical field of magnetic memories, and particularly relates to a preparation method for improving non-traditional spin-orbit torque efficiency by regulating and controlling Mn3Sn film crystal face orientation and application, and the preparation method comprises the following steps: (1) preparing Mn3Sn films with orientation of (or) on the surfaces of an Al2O3 (or) single crystal substrate and an MgO (110) single crystal substrate by using a magnetron sputtering technology by adopting a Mn3Sn alloy target material, and (2) preparing the Mn3Sn films with orientation of (or) on the surfaces of the Al2O3 (or) single crystal substrate and the MgO (110) single crystal substrate; (2) preparing a Mn3Sn film with the orientation of (or) on the surface of the MgO (111) single crystal substrate by using a magnetron sputtering technology; (3) preparing a Mn3Sn film with the orientation of (0002) or () on the surface of the SiO2 amorphous substrate by using a magnetron sputtering technology; and the Mn3Sn thin film is in a hexagonal crystal system. The Mn3Sn thin film prepared by the method shows a highly ordered crystal structure and spin arrangement, and clearly shows unique novel physical effect and topological electron transport behavior in a non-collinear antiferromagnetic material.

Description

Technical Field

[0001] This invention belongs to the field of magnetic memory technology, specifically relating to a preparation method and application of improving the efficiency of non-traditional spin-orbit torque by controlling the Mn3Sn crystal plane. Background Technology

[0002] With the rapid development of the information storage era, electronic storage devices are playing an increasingly important role in the entire materials system, attracting growing research interest. Magnetic random access memory (RAM), as a representative of such devices, has shown great potential in realizing high-frequency, high-stability, and low-energy-consumption storage devices due to its advantages such as long lifespan, low power consumption, and radiation resistance. With the rapid development of emerging technologies such as big data and the Internet of Things, the storage market is undergoing profound changes, placing higher demands on storage devices. Achieving high-density integration, ultra-low power consumption, and non-volatility has become a key research focus in current storage technology. The spin-orbit torque generated by heavy metal layers (such as Pt and Ta) driving the magnetic moment reversal of adjacent ferromagnetic layers is severely limited by its complex structure, high energy consumption, and stray fields, hindering breakthroughs in device performance and integration technology. Compared to ferromagnets, due to the presence of antiferromagnetic exchange interactions, antiferromagnets naturally exhibit higher spin dynamics in the terahertz range due to their ultrafast response, lack of net magnetic moment, and resistance to magnetic field interference, providing an opportunity for picosecond information writing technology. However, the core challenge in realizing antiferromagnetic memory and logic devices lies in how to efficiently use electricity to control the antiferromagnetic sequence to generate a strong spin-orbit torque.

[0003] Noncollinear antiferromagnetic materials have emerged as important new antiferromagnetic materials due to their remarkable physical properties, including a large anomalous Hall effect, magnetic spin Hall effect, and large anomalous Nernst effect. Noncollinear antiferromagnetic Mn3Sn stands out for its unique ability to intrinsically generate highly efficient spin-on-stem (SOT) structures. Whether in bulk or thin film form, it can exhibit coplanar noncollinear or non-coplanar spin structures, providing an ideal platform for constructing simpler and more energy-efficient antiferromagnetic devices. The physical uniqueness of Mn3Sn stems from its Kagome lattice-induced 120° noncollinear antiferromagnetic order—the three nearest-neighbor Mn atoms exhibit a triangular frustrated configuration, forming a chiral spin texture. This structure generates significant Berry curvature in momentum space, driving a topology-protected anomalous Hall effect and spin-polarized directional output.

[0004] Currently, with existing technologies, the crystal quality of Mn3Sn thin films prepared with different crystal orientations is not high, and there is still a lack of research on the control of non-traditional spin-orbit torque efficiency based on Mn3Sn crystal thin films with different crystal orientations. Therefore, this invention designs a method to improve the non-traditional spin-orbit torque efficiency by controlling the crystal orientation of Mn3Sn thin films. This invention can obtain high-quality Mn3Sn single-crystal thin films and Mn3Sn polycrystalline thin films, and simultaneously fabricate a spintronic device with a higher SOT efficiency compared to other substrates. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method and application for improving the non-traditional spin-orbit torque efficiency by controlling the Mn3Sn crystal planes. This method prepares Mn3Sn thin films with excellent crystal order, and successfully improves the non-traditional SOT efficiency by controlling Mn3Sn thin films with different crystal plane orientations. This invention is applicable to antiferromagnetic spintronic memory devices.

[0006] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0007] In a first aspect, the present invention provides a method for improving the non-traditional spin-orbit torque efficiency by controlling the Mn3Sn crystal plane, comprising at least one of the following schemes: (1) using Mn3Sn alloy target material, respectively on Al2O3 ( The orientation of the substrate was prepared by magnetron sputtering on the surface of a single crystal substrate and a MgO (110) single crystal substrate. Mn3Sn thin films;

[0008] (2) Using a Mn3Sn alloy target, a oriented ( ) was prepared on the surface of a MgO(111) single crystal substrate by magnetron sputtering. Mn3Sn thin films;

[0009] (3) Using a Mn3Sn alloy target, magnetron sputtering is employed to prepare a substrate with an orientation of (0002) or ( ) on a SiO2 amorphous substrate. Mn3Sn thin films;

[0010] The Mn3Sn thin film is hexagonal.

[0011] Preferably, when the Mn3Sn thin film crystal orientation is ( When Mn3Sn thin films are epitaxial, the relationship between Mn3Sn and the epitaxial relationship is Mn3Sn(

[0001] / / Al2O3 ( )[ ] or Mn3Sn(

[0001] / / MgO (110) [ ];

[0012] When the crystal orientation of the Mn3Sn thin film is (0002), the epitaxial relationship of the Mn3Sn thin film is Mn3Sn(0001). / / MgO (111) [ ];

[0013] When the Mn3Sn thin film crystal orientation is (0002), ( Mn3Sn grown on a SiO2 substrate is a non-epitaxy polycrystalline thin film.

[0014] Preferably, it includes the following steps:

[0015] S1: Al2O3 ( A single crystal substrate, MgO(110) single crystal substrate, MgO(111) single crystal substrate or SiO2 amorphous substrate is fixed on the sample plate;

[0016] S2: Using a Mn3Sn alloy target, a Mn3Sn thin film is deposited on the substrate surface of step S1 at 400-450℃. After deposition, in-situ annealing is performed at 400-450℃ to obtain the Mn3Sn thin film.

[0017] Preferably, in step S2, the sputtering condition is that the vacuum level is below 8 × 10⁻⁶. -8 The average growth rate of the thin film was 4.13-4.16 nm / min, and the film deposition thickness was 38-41 nm.

[0018] Preferably, in step S2, the deposition temperature is 400°C, the annealing temperature is 400°C, and the annealing time is 1 hour.

[0019] Preferably, the method further includes step S3: after the temperature drops to room temperature, a Ni2Fe8 thin film with a thickness of 100 mm is sputtered in situ, and then a Si3N4 thin film is sputtered in situ to prevent the sample from oxidizing.

[0020] Preferably, the thickness of the Ni2Fe8 film is 9-10 nm, and the thickness of the Si3N4 film is 3-5 nm.

[0021] Secondly, the present invention provides a non-collinear antiferromagnetic layer material Mn3Sn crystal thin film, which is prepared by the aforementioned preparation method.

[0022] Thirdly, the present invention provides the application of Mn3Sn crystal thin films, which are not collinear antiferromagnetic layer materials, to fabricate Mn3Sn / Py heterostructure devices using the Mn3Sn crystal thin films.

[0023] This invention successfully prepared a non-collinear antiferromagnetic layer material, Mn3Sn crystalline thin film, with crystal plane orientations including ( ), ( ), ( Subsequently, the Mn3Sn / Py heterojunction sample was processed into a 20×100 μm shape using ultraviolet exposure and argon ion etching. 2 The sample strips were then used to prepare a standard spin torque ferromagnetic resonance device using overlay technology. A wire was then led out from each of the three electrodes using aluminum wires to conduct high-frequency electrical transport tests.

[0024] Taking an alumina substrate as an example, the manufacturing method of the test device is along ( The direction of the external magnetic field is perpendicular to ( ). ) plane, current parallel to [ [Direction, fabricate test devices.]

[0025] The present invention has the following beneficial effects:

[0026] This invention provides a method for improving the non-traditional spin-orbit torque efficiency by controlling the crystal orientation of Mn3Sn thin films. The prepared Mn3Sn thin film material not only exhibits a highly ordered crystal structure and spin arrangement, but also clearly shows the unique and novel physical effects and topological electron transport behavior in non-collinear antiferromagnetic materials.

[0027] This invention directly reveals the dependence of antiferromagnetic order-related spin transport properties (especially spin orbital torque) in Mn3Sn thin films on crystal orientation by comparing spin torque ferromagnetic resonance measurements of Mn3Sn thin films with different orientations.

[0028] This invention, by comparing the spin torque ferromagnetic resonance (FMR) responses of thin films with different orientations, provides crucial experimental evidence for the intrinsic correlation between crystal structure, spin texture, and spin dynamics. It offers a new perspective for understanding the fundamental spin physics in the non-collinear antiferromagnetic Mn3Sn, quantitatively assesses the impact of crystal orientation on spin torque efficiency, and lays an important experimental foundation for future optimization of spintronic device performance based on antiferromagnetic Mn3Sn through interface and crystal orientation engineering. Attached Figure Description

[0029] The accompanying drawings are provided to further illustrate the invention and form part of the specification, serving to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0030] Figure 1 This is a schematic diagram of the unit cell structure of Mn3Sn, a non-collinear antiferromagnetic material with (0001) orientation;

[0031] Figure 2These are X-ray θ-2θ scans of Mn3Sn crystal thin films epitaxially grown on different substrates in embodiments of the present invention, wherein: (a) is Al2O3 ( Epitaxial growth of crystals with orientation ( ) on a single crystal substrate (a) X-ray θ-2θ scan of Mn3Sn single crystal thin film; (b) Epitaxial growth of Mn3Sn oriented ( ) on MgO(110) single crystal substrate. (c) X-ray θ-2θ scan of Mn3Sn single crystal thin film on MgO(111) single crystal substrate; (d) X-ray θ-2θ scan of Mn3Sn single crystal thin film on MgO(111) single crystal substrate with orientation ( The X-ray θ-2θ scan (d) of the Mn3Sn single crystal thin film is an epitaxial growth of an oriented Mn3Sn film on a SiO2 amorphous substrate. ), ( X-ray θ-2θ scan of Mn3Sn polycrystalline material;

[0032] Figure 3 This is a schematic diagram of the structure of a Mn3Sn / Py / Si3N4 heterojunction;

[0033] Figure 4 This is a diagram showing the experimental results of spin current generation in different Mn3Sn thin films epitaxially grown on different crystal plane orientations using spin torque ferromagnetic resonance in non-collinear antiferromagnetic Mn3Sn (40 nm) / Py (10 nm) samples epitaxially grown on different substrates in this invention. (a) is an Al2O3 ( Epitaxial growth of crystals with orientation ( ) on a single crystal substrate (a) Experimental results of spin current generation in Mn3Sn single crystal thin films; (b) Epitaxial growth of Mn3Sn single crystal thin films with orientation ( ) on MgO(110) single crystal substrates. (c) Experimental results of spin current generation in Mn3Sn single crystal thin films; (d) Epitaxial growth of Mn3Sn single crystal thin films with orientation ( ) on MgO(111) single crystal substrates. (d) shows the experimental results of spin current generation in Mn3Sn single crystal thin films; (d) shows the epitaxial growth of Mn3Sn single crystal thin films with an orientation of ( ) on a SiO2 amorphous substrate. ), ( Figure showing the experimental results of spin flow generation in Mn3Sn polycrystalline thin films. Detailed Implementation

[0034] The present invention will be further described below with reference to the embodiments and accompanying drawings:

[0035] In this invention, the Ni2Fe8 thin film is Py.

[0036] A method for preparing Mn3Sn thin films with different crystal orientations on Al2O3 ( The single-crystal substrates are MgO(110) single-crystal substrate, MgO(111) single-crystal substrate, and SiO2 amorphous substrate, with crystal orientations of (11) and (2) respectively. 0), (0002), (20 1).

[0037] Including at least one of the following schemes: (1) using Mn3Sn alloy target material, respectively in Al2O3 ( A (11) single crystal substrate and a MgO (110) single crystal substrate were prepared by magnetron sputtering with an orientation of (11) Mn3Sn thin film (0);

[0038] (2) Using Mn3Sn alloy target material, a Mn3Sn thin film with orientation (0002) was prepared on the surface of MgO(111) single crystal substrate by magnetron sputtering technology;

[0039] (3) Using a Mn3Sn alloy target, magnetron sputtering is used to prepare (0002) or (20) oriented crystals on the surface of an amorphous SiO2 substrate. 1) Mn3Sn thin film;

[0040] The Mn3Sn thin film is hexagonal.

[0041] Crystal orientation is (11) When 0), the epitaxial relationship of the thin film is Mn3Sn(11) 0)

[0001] ∥Al2O3(

[11] 0] or Mn3Sn (11 0)

[0001] ∥MgO(110)

[100] . When the crystal orientation is (0002), the epitaxial relationship of the thin film is Mn3Sn(0001)

[2110] ∥MgO(111)

[110] . When the crystal orientation of the Mn3Sn thin film is (0002) and (20), the epitaxial relationship of the thin film is Mn3Sn(0001)

[2110] ∥MgO(111)

[110] . 1) is a non-epitaxy polycrystalline Mn3Sn film grown on a SiO2 substrate.

[0042] Example 1

[0043] A method for improving the non-traditional spin-orbit torque efficiency by controlling the crystal orientation of Mn3Sn thin films, wherein the steps for preparing Mn3Sn crystal thin films with different Kagome orientations are as follows:

[0044] (1) Al2O (11 0) Single crystal substrate and MgO (110) single crystal substrate MgO (111) single crystal substrate and SiO2 amorphous substrate were ultrasonically cleaned and fixed on the sample plate with silver paste.

[0045] (2) The sample tray with the substrate fixed is transferred into the sputtering chamber through the sample transfer rod. The background vacuum is 8×10⁻⁶. -8 mTorr, after the sample disk is fixed in the sputtering chamber, the temperature is increased to 400 ℃ at a rate of less than 0.3 ℃ / s, and held for 2 h to ensure that the temperature of both the chamber and the substrate reaches 400 ℃.

[0046] (3) During growth, the substrate temperature was kept stable at 400 °C, the average growth rate of the thin film was controlled at 4.15 nm / min, and the epitaxial growth was carried out for 10 min 50 s to obtain a Mn3Sn crystal thin film with a thickness of 40 nm.

[0047] Successfully fabricated Mn3Sn crystalline thin films of non-collinear antiferromagnetic layer materials, with crystal plane orientations including (11... 0), (0002), (20 1).

[0048] Figure 1 This is a schematic diagram of the unit cell structure of Mn3Sn, a non-collinear antiferromagnetic material with (0001) orientation; Figure 2 For the characterization of the crystal structure properties of the Mn3Sn thin film prepared in this embodiment, (a) and (b) are respectively obtained by etching Al2O3 (… X-ray θ-2θ scans of Mn3Sn thin films grown on MgO(110) single-crystal substrates are shown. The results indicate that, in addition to the characteristic peaks of the substrate, 2θ values ​​for Mn3Sn(110) thin films appear near 31.58 ° and 65.96 °. 0) and (22) The diffraction peak of 0).

[0049] (c) is the θ-2θ scan of the X-rays of the Mn3Sn thin film grown on the MgO(111) single crystal substrate. In addition to the characteristic peaks of the substrate, strong Mn3Sn(0002) and (0004) diffraction peaks appear at 39.74 ° and 85.84 °.

[0050] (d) On the SiO2 amorphous substrate, in addition to the characteristic peaks of the substrate and a strong Mn3Sn(0002) diffraction peak near 2θ at 39.87 °, a Mn3Sn(20) diffraction peak also appears at 2θ at 41.24 °. 1) Diffraction peaks.

[0051] In this embodiment, by employing lattice-matched Al2O (11 Four different substrates, including single crystal substrate, MgO (110) single crystal substrate, MgO (111) single crystal substrate, and SiO2 amorphous substrate, were used to demonstrate the precise control of the Kagome plane and different crystal orientations, and to achieve the successful preparation of epitaxial growth of different crystals.

[0052] Example 2

[0053] Mn3Sn (40 nm) / Py (10 nm) heterojunction samples were prepared for spin torque ferromagnetic resonance experiments.

[0054] Based on steps (1)-(3), after the chamber cools to room temperature, a 10 nm Py film is sputtered in situ and covered with a 3 nm Si3N4 film to prevent oxidation. The structural diagram is shown below. Figure 3 As shown.

[0055] Subsequently, the Mn3Sn / Py heterojunction sample was processed into a 20×100 μm shape using ultraviolet exposure and argon ion etching. 2 The sample strips were then used to prepare a standard spin torque ferromagnetic resonance device using overlay technology. A wire was then led out from each of the three ports of the prepared device using aluminum wires for high-frequency electrical transport testing.

[0056] Figure 4 This is an experimental result diagram of spin current generation in different Mn3Sn thin films epitaxially grown with different crystal plane orientations using spin torque ferromagnetic resonance in non-collinear antiferromagnetic Mn3Sn (40 nm) / Py (10 nm) samples epitaxially grown on different substrates in this invention embodiment. Both in-plane and out-of-plane spin polarization exist. (a) is Al2O3 ( Epitaxial growth of crystals with orientation ( ) on a single crystal substrate (a) Experimental results of spin current generation in Mn3Sn single crystal thin films; (b) Epitaxial growth of Mn3Sn single crystal thin films with orientation ( ) on MgO(110) single crystal substrates. (c) Experimental results of spin current generation in Mn3Sn single crystal thin films; (d) Epitaxial growth of Mn3Sn single crystal thin films with orientation ( ) on MgO(111) single crystal substrates. (d) shows the experimental results of spin current generation in Mn3Sn single crystal thin films; (d) shows the epitaxial growth of Mn3Sn single crystal thin films with an orientation of ( ) on a SiO2 amorphous substrate. ), ( Experimental results of spin current generation in Mn3Sn polycrystalline thin films are shown. Spin torque ferromagnetic resonance experiments, conducted at room temperature and dependent on the magnetic field angle, were performed. The results show that the relationship satisfies the out-of-plane torque V in the Py layer. A Originating from in-plane spin polarization in the y-direction, and in-plane torque V S It originates from out-of-plane spin polarization in the z-direction. This out-of-plane polarization component is crucial for the application of perpendicular magnetization devices because it can drive magnetization reversal in the absence of an external magnetic field, and its reversal efficiency is superior to that of in-plane polarization.

[0057] Furthermore, by comparing the test results of Mn3Sn / Py heterojunction samples epitaxially grown on four different substrates, we revealed through angle-resolved ST-FMR measurements that the SOT efficiency is directly related to the Kagome planar crystal orientation of Mn3Sn.

[0058] It is worth noting that Al2O3 ( Epitaxial growth on a single crystal substrate The unconventional SOT efficiency of Mn3Sn crystal films with Kagome lattice orientation is the highest, which is directly related to the spin polarization anisotropy regulated by Kagome lattice orientation. This dramatic change is due to the symmetry breaking caused by Mn3Sn crystal films epitaxially grown on different substrates, which amplifies the out-of-plane spin polarization current component.

[0059] The above description explains the phenomena and results of the present invention, and this embodiment does not limit the invention. Further non-inventive modifications can be made while maintaining the spirit and scope of the invention. However, all modifications within the scope of the claims of the present invention are protected by patent law.

Claims

1. A method for preparing unconventional spin-orbit torque efficiency by controlling the Mn3Sn crystal plane, characterized in that: Including at least one of the following schemes: (1) using Mn3Sn alloy target material, respectively in Al2O3 ( The orientation of the substrate was prepared by magnetron sputtering on the surface of a single crystal substrate and a MgO (110) single crystal substrate. Mn3Sn thin films; (2) Using a Mn3Sn alloy target, a oriented ( ) was prepared on the surface of a MgO(111) single crystal substrate by magnetron sputtering. Mn3Sn thin films; (3) Using a Mn3Sn alloy target, magnetron sputtering is employed to prepare a substrate with an orientation of (0002) or ( ) on a SiO2 amorphous substrate. Mn3Sn thin films; The Mn3Sn thin film is hexagonal.

2. The preparation method for improving the non-traditional spin-orbit torque efficiency by controlling the Mn3Sn crystal plane according to claim 1, characterized in that: When the Mn3Sn thin film crystal orientation is ( When Mn3Sn thin films are epitaxial, the relationship between Mn3Sn and the epitaxial relationship is Mn3Sn( [0001] / / Al2O3 ( )[ ] or Mn3Sn( [0001] / / MgO (110) [ ]; When the crystal orientation of the Mn3Sn thin film is (0002), the epitaxial relationship of the Mn3Sn thin film is Mn3Sn(0001). / / MgO (111) [ ]; When the Mn3Sn thin film crystal orientation is (0002), ( Mn3Sn grown on a SiO2 substrate is a non-epitaxy polycrystalline thin film.

3. The preparation method for improving the non-traditional spin-orbit torque efficiency by controlling the Mn3Sn crystal plane according to claim 1, characterized in that: Includes the following steps: S1: Al2O3 ( A single crystal substrate, MgO(110) single crystal substrate, MgO(111) single crystal substrate or SiO2 amorphous substrate is fixed on the sample plate; S2: Using a Mn3Sn alloy target, a Mn3Sn thin film is deposited on the substrate surface of step S1 at 400-450℃. After deposition, in-situ annealing is performed at 400-450℃ to obtain the Mn3Sn thin film.

4. The preparation method for improving the non-traditional spin-orbit torque efficiency by controlling the Mn3Sn crystal plane according to claim 3, characterized in that: In step S2, the sputtering condition is that the vacuum level is below 8 × 10⁻⁶. -8 The average growth rate of the thin film was 4.13-4.16 nm / min, and the film deposition thickness was 38-41 nm.

5. The preparation method for improving the non-traditional spin-orbit torque efficiency by controlling the Mn3Sn crystal plane according to claim 3, characterized in that: In step S2, the deposition temperature is 400℃, the annealing temperature is 400℃, and the annealing time is 1h.

6. The preparation method for improving the non-traditional spin-orbit torque efficiency by controlling the Mn3Sn crystal plane according to claim 3, characterized in that: It also includes step S3: after the temperature drops to room temperature, a Ni2Fe8 thin film with a thickness of 100 mm is sputtered in situ, and then a Si3N4 thin film is sputtered in situ to prevent the sample from oxidizing.

7. The preparation method for improving the non-traditional spin-orbit torque efficiency by controlling the Mn3Sn crystal plane according to claim 3, characterized in that: The thickness of the Ni2Fe8 film is 9-10 nm, and the thickness of the Si3N4 film is 3-5 nm.

8. A Mn3Sn crystal thin film of a non-collinear antiferromagnetic layer material, characterized in that: It is prepared by any one of claims 1-7.

9. An application of a Mn3Sn crystal thin film of a non-collinear antiferromagnetic layer material according to claim 8, characterized in that: Mn3Sn / Py heterostructure devices were fabricated using the aforementioned Mn3Sn crystal thin film.

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