Magnetic multilayer film and method of making and use thereof

Abstract

The application relates to a magnetic multilayer film and a preparation method and application thereof. The magnetic multilayer film comprises a substrate and a heavy metal layer, a ferromagnetic layer, a rare earth magnetic alloy layer, a rare earth metal layer, a light metal layer and a protective cover layer which are sequentially arranged on the substrate; the heavy metal layer is configured to generate spin current under the action of current and acts on the ferromagnetic layer in the form of spin-orbit torque; the light metal layer is configured to generate orbital current under the action of current; the rare earth metal layer and the rare earth magnetic alloy layer are configured to convert the orbital current into orbital torque and act on the rare earth magnetic alloy layer; the orbital torque and the spin-orbit torque synergistically act to reduce the critical current of magnetization reversal of the magnetic multilayer film. The magnetic multilayer film of the application realizes orbital torque synergistic driving, significantly reduces the critical current of magnetization reversal of the device, and is beneficial to the preparation of high-efficiency and low-power-consumption spintronic devices.

Description

Technical Field

[0001] This invention belongs to the field of spintronic devices. Specifically, this invention relates to a magnetic multilayer film, its preparation method, and its uses; this invention also relates to spintronic devices comprising the magnetic multilayer film. Background Technology

[0002] The spin-orbital torque (SOT) effect utilizes spin to convert current into spin current through a heavy metal layer with a large spin Hall effect in the spin electronic storage device. This spin current then acts on the adjacent ferromagnetic layer as a spin-orbital torque, causing the magnetism of the ferromagnetic layer to flip. Spin electronic storage devices have advantages such as all-current drive and read / write path separation. The critical flip current is an important indicator of the power consumption of spin electronic storage devices; the smaller the critical flip current, the lower the power consumption required by the device. The main factor affecting the power consumption required by the device is the torque acting on the ferromagnetic layer in the device. Heavy metal materials with a large spin Hall effect generally have a large spin-orbital torque, such as platinum (Pt), tantalum (Ta), tungsten (W), and alloys containing these elements.

[0003] Besides the spin-orbit moments generated by heavy metal materials with large spin Hall effects, some 3d and 4d light metals, such as Ti, Zr, and Ru, while having very small spin Hall effects, have very large orbital Hall effects, even larger than those of commonly used 5d heavy metals. Similar to spin-orbit moments, when current passes through a light metal layer with a large orbital Hall effect in a device, it can be converted into an orbital current, which then acts as an orbital moment (OT) on the adjacent ferromagnetic layer, causing a reversal of the ferromagnetic layer's magnetism. Unlike spin currents, orbital currents need to be converted into spin currents first before they can act on the adjacent ferromagnetic layer and generate a sufficiently large orbital moment.

[0004] While significant progress has been made in spintronic memory devices driven by spin currents or orbitals, several key challenges remain. Existing solutions largely rely on a single heavy or light metal layer to generate spin-orbit moments or orbital moments. Although this method offers high compatibility with existing semiconductor processes and is easier to integrate than some two-dimensional materials, the critical current density required for magnetization reversal is generally quite high, typically exceeding 1 × 10⁻⁶. 7 The high power consumption (A / cm²) remains a problem that urgently needs to be solved.

[0005] Therefore, there is an urgent need to develop new methods to reduce the critical current for magnetization reversal, thereby achieving low power consumption of spintronic memory devices. Summary of the Invention

[0006] To address the above problems, the present invention aims to provide a magnetic multilayer film, its preparation method, and its applications. The invention also relates to spintronic devices comprising the magnetic multilayer film. By introducing the synergistic effect of orbital moments into the magnetic multilayer film, the present invention significantly reduces the critical current for magnetization reversal in spintronic devices, thereby enhancing the performance of devices in magnetic storage and spintronics fields and reducing their power consumption.

[0007] The above-mentioned objective of the present invention is achieved by providing the following technical solution:

[0008] In a first aspect, the present invention provides a magnetic multilayer film comprising:

[0009] Substrate; and

[0010] A heavy metal layer, a ferromagnetic layer, a rare earth magnetic alloy layer, a rare earth metal layer, a light metal layer, and a protective covering layer are sequentially stacked on the substrate.

[0011] Wherein, the heavy metal layer is configured to generate a spin current under the action of an electric current and act on the ferromagnetic layer in the form of a spin orbital moment; the light metal layer is configured to generate an orbital current under the action of an electric current; the rare earth metal layer and the rare earth magnetic alloy layer are configured to convert the orbital current into an orbital moment and act on the rare earth magnetic alloy layer.

[0012] The orbital moment and the spin orbital moment work together to reduce the critical current for magnetization reversal of the magnetic multilayer film.

[0013] In the field of magnetic multilayer films for spintronic devices, "heavy metals" and "light metals" are not classified according to traditional density, but rather based on the strength of their spin-orbit coupling (SOC) effect. The term "heavy metal" refers to metals with strong spin-orbit coupling (typical SOC values ​​of approximately ≥0.1 eV), capable of generating spin current under current-driven conditions due to their large spin Hall effect. The term "light metal" refers to metals with extremely weak or negligible spin-orbit coupling (typical SOC values ​​of approximately ≤0.05 eV), which do not generate spin current, but often possess a very large orbital Hall effect, capable of producing significant orbital current.

[0014] In the magnetic multilayer film provided by this invention, on the one hand, a light metal layer exhibiting a large orbital Hall effect generates an orbital current under current induction, which then generates an orbital moment through the rare-earth metal layer and the rare-earth magnetic alloy layer, acting on the rare-earth magnetic alloy layer; on the other hand, a heavy metal layer generates a spin current under current induction and acts on the ferromagnetic layer in the form of a spin orbital moment. In this case, the orbital moment and the spin orbital moment exhibit a synergistic enhancement effect, significantly reducing the critical current for magnetization reversal of the device, which is beneficial for fabricating high-efficiency, low-power spintronic devices, and is particularly suitable for magnetic storage and magnetic logic devices.

[0015] According to the magnetic multilayer film provided by the present invention, the substrate material is selected from one or more of silicon, glass, aluminum oxide and magnesium oxide.

[0016] According to the magnetic multilayer film provided by the present invention, the material of the heavy metal layer is selected from one or more of Pt, Ta, W, Pd and Ir, or an alloy formed by any combination thereof.

[0017] In the magnetic multilayer film provided by the present invention, the heavy metal layer has a strong spin Hall effect (SHE) to generate spin current.

[0018] According to the magnetic multilayer film provided by the present invention, the material of the ferromagnetic layer is selected from one or more of Co, CoFeB and CoFe.

[0019] In the magnetic multilayer film provided by the present invention, the ferromagnetic layer and the heavy metal layer are adjacent, forming a structure with perpendicular magnetism, such as Pt / Co structure, Pt / CoFe structure and Pt / CoFeB structure.

[0020] According to the magnetic multilayer film provided by the present invention, the material of the rare earth magnetic alloy layer is selected from one or more of CoGd, CoHo, CoTb and CoFeGd, preferably CoGd and / or CoTb.

[0021] In the magnetic multilayer film provided by this invention, the rare earth magnetic alloy layer is the key structure for realizing the coordinated drive of orbital moments. It is located above the vertical magnetic ferromagnetic layer and can be directly coupled with the ferromagnetic layer. At the same time, it has a large orbital-spin conversion efficiency and can also effectively accept the orbital moments generated by the orbital flow from the light metal layer.

[0022] According to the magnetic multilayer film provided by the present invention, the material of the rare earth metal layer is selected from one or more of Gd, Tb, Ho and Tb, preferably Gd and / or Tb.

[0023] In the magnetic multilayer film provided by the present invention, the rare earth metal layer has a large orbital-spin conversion efficiency, which ensures that the orbital flow generated by the large orbital Hall effect can fully form orbital moments.

[0024] According to the magnetic multilayer film provided by the present invention, the material of the light metal layer is selected from one or more of Ti, Cr, Zr, V and Ru, or an alloy formed by any combination thereof.

[0025] In the magnetic multilayer film provided by the present invention, the light metal layer has a strong orbital Hall effect (OHE) to generate orbital flow.

[0026] According to the magnetic multilayer film provided by the present invention, the material of the protective covering layer is selected from one or more of silicon dioxide, magnesium oxide, aluminum oxide, tantalum oxide, silicon nitride, aluminum nitride and titanium nitride.

[0027] In the magnetic multilayer film provided by this invention, a protective layer is used to protect the structure and performance of the spin orbital moment device, ensuring its stability and reliability under different environmental conditions.

[0028] According to the magnetic multilayer film provided by the present invention, the atomic proportion of rare earth elements in the material of the rare earth magnetic alloy layer is 10-90%, preferably 60-80%.

[0029] According to the magnetic multilayer film provided by the present invention, the thickness of the heavy metal layer is 1-10 nm, preferably 2-4 nm.

[0030] According to the magnetic multilayer film provided by the present invention, the thickness of the ferromagnetic layer is 0.5-2 nm, preferably 1-2 nm.

[0031] According to the magnetic multilayer film provided by the present invention, the thickness of the rare earth magnetic alloy layer is 0.5-4 nm, preferably 1-2 nm.

[0032] According to the magnetic multilayer film provided by the present invention, the thickness of the rare earth metal layer is 1-5 nm, preferably 2-4 nm.

[0033] According to the magnetic multilayer film provided by the present invention, the thickness of the light metal layer is 2-20 nm, preferably 5-12 nm.

[0034] According to the magnetic multilayer film provided by the present invention, the thickness of the protective covering layer is 1-5 nm, preferably 1-3 nm.

[0035] According to the magnetic multilayer film provided by the present invention, the magnetic multilayer film further includes a protective layer stacked on top of the protective covering layer.

[0036] In the magnetic multilayer film provided by the present invention, the protective layer is used to prevent the underlying thin film structure from being oxidized, thereby improving stability.

[0037] According to the magnetic multilayer film provided by the present invention, the magnetic multilayer film further includes a buffer layer stacked between the substrate and the heavy metal layer.

[0038] In the magnetic multilayer film provided by the present invention, a buffer layer is used for the growth of a heavy metal layer thereon, including providing a preferred orientation for the growth of the multilayer film and enhancing the adhesion between the film layer and the substrate.

[0039] According to the magnetic multilayer film provided by the present invention, the material of the protective layer is selected from one or more of Ta, silicon dioxide, magnesium oxide, aluminum oxide, tantalum oxide, silicon nitride, aluminum nitride and titanium nitride.

[0040] According to the magnetic multilayer film provided by the present invention, the material of the buffer layer is selected from one or more of Ta, Ti, Zr and Ru.

[0041] According to the magnetic multilayer film provided by the present invention, the thickness of the protective layer is 1-5 nm, preferably 1-2 nm.

[0042] According to the magnetic multilayer film provided by the present invention, the thickness of the buffer layer is 0.5-3 nm, preferably 1-2 nm.

[0043] In a second aspect, the present invention provides a method for preparing the magnetic multilayer film described in the first aspect of the present invention, which includes: sequentially depositing a heavy metal layer, a ferromagnetic layer, a rare earth magnetic alloy layer, a rare earth metal layer, a light metal layer, and a protective coating layer on the substrate using physical vapor deposition.

[0044] According to the preparation method provided by the present invention, the method further includes: depositing a buffer layer between the substrate and the heavy metal layer.

[0045] According to the preparation method provided by the present invention, the method further includes: depositing a protective layer on top of the protective covering layer.

[0046] According to the preparation method provided by the present invention, the physical vapor deposition method is selected from one or more of magnetron sputtering, molecular beam epitaxy, pulsed laser method and electron beam evaporation method.

[0047] Thirdly, the present invention provides a spintronic device comprising the magnetic multilayer film described in the first aspect of the present invention or the magnetic multilayer film prepared by the preparation method described in the second aspect of the present invention.

[0048] In the spintronic device provided by this invention, a DC pulse current is first applied to the Hall structure formed by microfabrication (the Hall structure is prepared by micro-nano processing such as photolithography, ion beam etching, resist removal, and electron beam evaporation after multilayer film deposition), and then a constant small DC pulse current is applied to measure the Hall voltage. Since the entire device will simultaneously have a spin orbital moment acting on the ferromagnetic layer and an orbital moment acting on the rare earth magnetic alloy layer, this synergistic driving effect leads to a significant reduction in the critical switching current of the device, thereby obtaining a high-efficiency, low-power electronic device.

[0049] According to the spintronic device provided by the present invention, the spintronic device is a spin memory device or a logic device; preferably, the spin memory device is a non-volatile magnetic random access memory.

[0050] Fourthly, the present invention provides the use of the magnetic multilayer film described in the first aspect of the present invention or the magnetic multilayer film prepared by the preparation method described in the second aspect of the present invention in spintronic devices.

[0051] According to the spintronic device provided by the present invention, the spintronic device is a spin memory device or a logic device; preferably, the spin memory device is a non-volatile magnetic random access memory.

[0052] The present invention has at least the following beneficial effects:

[0053] (1) The magnetic multilayer film of the present invention can improve the effective spin-orbit moment efficiency of the device. Specifically, the torque of the current acting on the magnetic layer includes two parts: one is the positive spin-orbit moment induced from the bottom up by the heavy metal layer, and the other is the orbital moment from the light metal layer. Through the rare earth metal layer with a large negative orbital-spin conversion efficiency, a negative orbital moment is generated from the top down and acts on the rare earth magnetic alloy layer. Finally, the effective spin-orbit moment applied to the overall magnetic layer is synergistically enhanced, thereby improving the effective spin-orbit moment efficiency of the spintronic device containing the magnetic multilayer film.

[0054] (2) The magnetic multilayer film of the present invention can reduce the power consumption of spintronic devices. Specifically, the rare earth magnetic alloy layer can further reduce the critical switching current density of the device, thereby greatly reducing the power consumption of the device.

[0055] (3) The preparation method of the present invention is simple and convenient. The spintronic device involved has the advantages of high storage density and non-volatility. It shows broad application prospects in the fields of controllable magnetic memory and logic device, and provides a high-performance and unique solution for the field of spintronics. Attached Figure Description

[0056] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings, wherein:

[0057] Figure 1 This illustrates the structure of a low-power spin memory device driven by orbital moment coordination according to Embodiment 1 of the present invention;

[0058] In the attached figures, the reference numerals are as follows: 100-substrate; 101-heavy metal layer; 102-ferromagnetic layer; 103-rare earth magnetic alloy layer; 104-rare earth metal layer; 105-light metal layer; 106-covering protective layer.

[0059] Figure 2 The current drive test results of the low-power spin memory device with orbital moment cooperative drive according to Embodiment 1 of the present invention are shown.

[0060] Figure 3 The current drive test results of the comparison device in Comparative Example 1 are shown.

[0061] Figure 4 The current drive test results of the comparison device in Comparative Example 2 are shown.

[0062] Figure 5 This diagram shows the principle of the present invention based on track moment cooperative drive. Detailed Implementation

[0063] The present invention will be further described in detail below with reference to specific embodiments. The embodiments given are only for illustrating the present invention and are not intended to limit the scope of the present invention.

[0064] Unless otherwise specified, the methods or conditions used in the following embodiments are performed according to conventional methods disclosed in the art. Unless otherwise stated, the instruments or materials used in the following embodiments are commercially available products.

[0065] Example 1

[0066] like Figure 1 As shown, the magnetic multilayer film of this embodiment includes a substrate 100 and a heavy metal layer 101, a ferromagnetic layer 102, a rare earth magnetic alloy layer 103, a rare earth metal layer 104, a light metal layer 105, a cover protective layer 106, and a protective layer (not shown in the figure) stacked on the substrate 100 from bottom to top.

[0067] The preparation method of this magnetic multilayer film is as follows:

[0068] (1) The Si substrate 100 with a 300 nm SiO2 coating was ultrasonically cleaned for 30 minutes in sequence with isopropanol, alcohol and deionized water. Then the substrate 100 was dried with dry clean air. The cleaned substrate 100 was then placed into the growth chamber of magnetron sputtering with a vacuum degree of 5 × 10⁻⁶. -6 Pa, high-purity argon gas is introduced to stabilize the gas pressure during sputtering at around 0.5 Pa;

[0069] (2) Using a DC or RF power supply with a power of about 10 W, a 3 nm Pt heavy metal layer 101 is deposited on the substrate 100 as a spin flow generation layer.

[0070] (3) Using a DC or RF power supply with a power of 15 W, a 1 nm Co layer is deposited on the Pt heavy metal layer 101 as a ferromagnetic layer 102. Pt / Co can form a vertical anisotropy, so that the device including the structure has a vertical magnetic layer.

[0071] (4) Using an RF power supply with a power of 20 W, deposit 1 nm of Co on the Co ferromagnetic layer 102. 30 Gd 70 Rare earth magnetic alloy layer 103;

[0072] (5) Use a DC or RF power supply with a power of 20 W, in Co 30 Gd 70 A 3 nm Gd rare earth metal layer 104 is deposited on the rare earth magnetic alloy layer 103.

[0073] (6) Using an RF power supply with a power of 20 W, a 10 nm Zr light metal layer 105 is deposited on the Gd rare earth metal layer 104;

[0074] (7) Using an RF power supply with a power of 50 W, a 3 nm MgO thin film is deposited on the Zr light metal layer 105 as a protective covering layer 106.

[0075] (8) In order to better protect the device, a DC power supply with a power of 15 W is used to deposit a 1 nm Ta layer on the protective layer 106 as a protective layer 107 to prevent the underlying thin film structure from being oxidized, thereby improving stability.

[0076] Hall devices are formed by micro- and nano-fabrication of annealed magnetic multilayer films using methods such as photolithography, argon ion beam etching, plasma resist removal, and electron beam evaporation.

[0077] Current-induced magnetization reversal was measured using a Keithley 6221 and 2182A source meter combination. A DC pulsed current was applied to the Hall device, and then the Hall voltage was measured to obtain the current-driven magnetization reversal curve of the device under a 30 mT magnetic field, as shown below. Figure 2 As shown, in this device, Pt / Co / Co 30 Gd 70 The magnetization is reversed by the current driven by / Gd / Zr, and the critical current density for the magnetization reversal is 2.5 × 10⁻⁶. 6 A / cm 2 .

[0078] Comparative Example 1

[0079] The difference from Example 1 is that the magnetic multilayer film prepared in this comparative example does not include the rare earth magnetic alloy layer 103, and the thickness of the rare earth metal layer 104 is 4 nm. The specific preparation method is as follows:

[0080] (1) The Si substrate 100 with a 300 nm SiO2 coating was ultrasonically cleaned for 30 minutes in sequence with isopropanol, alcohol and deionized water. Then the substrate 100 was dried with dry clean air. The cleaned substrate 100 was then placed into the growth chamber of magnetron sputtering with a vacuum degree of 5 × 10⁻⁶. -6 Pa, high-purity argon gas is introduced to stabilize the gas pressure during sputtering at around 0.5 Pa;

[0081] (2) Using a DC or RF power supply with a power of about 10 W, a 3 nm Pt heavy metal layer 101 is deposited on the substrate 100 as a spin flow generation layer.

[0082] (3) Using a DC or RF power supply with a power of 15 W, a 1 nm Co layer is deposited on the Pt heavy metal layer 101 as a ferromagnetic layer 102. Pt / Co can form a vertical anisotropy, so that the device including the structure has a vertical magnetic layer.

[0083] (4) Using a DC or RF power supply with a power of 20 W, deposit a 4 nm Gd rare earth metal layer 104 on the Co ferromagnetic layer 102.

[0084] (5) Using an RF power supply with a power of 20 W, a 10 nm Zr light metal layer 105 is deposited on the Gd rare earth metal layer 104;

[0085] (6) Using an RF power supply with a power of 50 W, a 3 nm MgO thin film is deposited on the Zr light metal layer 105 as a protective covering layer 106.

[0086] (7) In order to better protect the device, a DC power supply with a power of 15 W is used to deposit a 1 nm Ta layer on the protective layer 106 as a protective layer 107 to prevent the underlying thin film structure from being oxidized, thereby improving stability.

[0087] The magnetic multilayer film prepared by the above method was micro- or nano-fabricated using the same method as in Example 1 to form a Hall device.

[0088] Current-induced magnetization reversal was measured using a Keithley 6221 and 2182A source meter combination. A DC pulsed current was applied to the Hall device, and then the Hall voltage was measured to obtain the current-driven magnetization reversal curve of the device under a 30 mT magnetic field, as shown below. Figure 3As shown, in this device, the current drives the magnetization reversal of the Pt / Co / Gd / Zr ratio, and the critical current density for magnetization reversal is 8 × 10⁻⁶. 6 A / cm 2 .

[0089] Comparative Example 2

[0090] The difference from Example 1 is that the magnetic multilayer film prepared in this comparative example does not include the rare earth magnetic alloy layer 103 and the rare earth metal layer 104. The specific preparation method is as follows:

[0091] (1) The Si substrate 100 with a 300 nm SiO2 coating was ultrasonically cleaned for 30 minutes in sequence with isopropanol, alcohol and deionized water. Then the substrate 100 was dried with dry clean air. The cleaned substrate 100 was then placed into the growth chamber of magnetron sputtering with a vacuum degree of 5 × 10⁻⁶. -6 Pa, high-purity argon gas is introduced to stabilize the gas pressure during sputtering at around 0.5 Pa;

[0092] (2) Using a DC or RF power supply with a power of about 10 W, a 3 nm Pt heavy metal layer 101 is deposited on the substrate 100 as a spin flow generation layer.

[0093] (3) Using a DC or RF power supply with a power of 15 W, a 1 nm Co layer is deposited on the Pt heavy metal layer 101 as a ferromagnetic layer 102. Pt / Co can form a vertical anisotropy, so that the device including the structure has a vertical magnetic layer.

[0094] (4) Using an RF power supply with a power of 20 W, a 10 nm Zr light metal layer 105 is deposited on the Co ferromagnetic layer 102;

[0095] (5) Using an RF power supply with a power of 50 W, a 3 nm MgO thin film is deposited on the Zr light metal layer 105 as a protective covering layer 106.

[0096] (6) In order to better protect the device, a DC power supply with a power of 15 W is used to deposit a 1 nm Ta layer on the protective layer 106 as a protective layer 107 to prevent the underlying thin film structure from being oxidized, thereby improving stability.

[0097] The magnetic multilayer film prepared in this comparative example was micro- or nano-fabricated using the same method as in Example 1 to form a Hall device.

[0098] Current-induced magnetization reversal was measured using a Keithley 6221 and 2182A source meter combination. A DC pulsed current was applied to the Hall device, and then the Hall voltage was measured to obtain the current-driven magnetization reversal curve of the device under a 30 mT magnetic field, as shown below. Figure 4As shown, in this device, the Pt / Co / Zr current drives the magnetization reversal, and the critical current density for magnetization reversal is 2 × 10⁻⁶. 7 A / cm 2 .

[0099] The principle of the low-power electronic storage device based on orbital moment cooperative drive of the present invention is as follows: Figure 5 As shown. The unique feature of this invention is that it utilizes orbital current to generate orbital moments from the top through the rare earth metal layer 104 and the rare earth magnetic alloy layer 103, acting on the rare earth magnetic alloy layer 103, and spin current to act on the ferromagnetic layer 102 from the bottom in the form of spin orbital moments. Although the spin current and orbital current are in opposite directions, the orbital current, when passing through the rare earth metal layer 104 and the rare earth magnetic alloy layer 103, has a negative orbital-spin conversion coefficient, so the sign of the generated orbital moments is consistent with the direction of the spin orbital moments. This allows them to act synergistically and consistently on the ferromagnetic layer 102 of the device, greatly enhancing the torque induced by the effective current and significantly reducing the critical current for magnetization reversal.

[0100] Conversely, if the rare-earth magnetic alloy layer 103 is missing, as in Comparative Example 1, efficient generation of orbital moments cannot be achieved. If both the rare-earth metal layer 104 and the rare-earth magnetic alloy layer 103 are missing, as in Comparative Example 2, due to the lack of efficient orbital-spin-switching between the light metal layer 105 and the ferromagnetic layer 102, synergistic enhancement of orbital moments cannot be achieved. Therefore, neither Comparative Examples 1 nor 2 can significantly reduce the critical current for magnetization reversal.

[0101] The preparation method of this invention is simple and convenient, and the spintronic devices involved have the advantages of high storage density and non-volatility, showing broad application prospects in fields such as controllable magnetic memory and logic devices, and providing a high-performance and unique solution for the field of spintronics.

[0102] The above descriptions are merely several exemplary embodiments of the present invention and are not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any equivalent or similar implementation schemes obtained by those skilled in the art by making some modifications or alterations to the above-disclosed technical content without departing from the scope of the present invention are within the scope of the present invention.

Claims

1. A magnetic multilayer film, characterized in that, The magnetic multilayer film includes: Substrate; and A heavy metal layer, a ferromagnetic layer, a rare earth magnetic alloy layer, a rare earth metal layer, a light metal layer, and a protective covering layer are sequentially stacked on the substrate. Wherein, the heavy metal layer is configured to generate a spin current under the action of an electric current and act on the ferromagnetic layer in the form of a spin orbital moment; the light metal layer is configured to generate an orbital current under the action of an electric current; the rare earth metal layer and the rare earth magnetic alloy layer are configured to convert the orbital current into an orbital moment and act on the rare earth magnetic alloy layer, and The rare earth magnetic alloy layer is located above the vertical magnetic ferromagnetic layer and is configured to be directly coupled to the ferromagnetic layer. The orbital moment and the spin orbital moment work together to reduce the critical current for magnetization reversal of the magnetic multilayer film.

2. The magnetic multilayer film according to claim 1, characterized in that, The substrate material is selected from one or more of silicon, glass, alumina, and magnesium oxide; and / or The material of the heavy metal layer is selected from one or more of Pt, Ta, W, Pd and Ir, or an alloy formed by any combination thereof; and / or The material of the ferromagnetic layer is selected from one or more of Co, CoFeB, and CoFe; and / or The rare earth magnetic alloy layer is made of one or more of CoGd, CoHo, CoTb, and CoFeGd; and / or The rare earth metal layer is made of one or more of Gd, Tb, Ho, and Tb; and / or The material of the light metal layer is selected from one or more of Ti, Cr, V, Zr and Ru, or an alloy formed by any combination thereof; and / or The material of the protective layer is selected from one or more of silicon dioxide, magnesium oxide, aluminum oxide, tantalum oxide, silicon nitride, aluminum nitride, and titanium nitride.

3. The magnetic multilayer film according to claim 2, characterized in that, The rare earth magnetic alloy layer contains rare earth elements in an atomic ratio of 10-90%.

4. The magnetic multilayer film according to claim 1, characterized in that, The thickness of the heavy metal layer is 1-10 nm; and / or The thickness of the ferromagnetic layer is 0.5-2 nm; and / or The thickness of the rare earth magnetic alloy layer is 0.5-4 nm; and / or The thickness of the rare earth metal layer is 1-5 nm; and / or The thickness of the light metal layer is 2-20 nm; and / or The thickness of the protective layer is 1-5 nm.

5. The magnetic multilayer film according to claim 1, characterized in that, The magnetic multilayer film further includes a protective layer stacked on top of the protective overlay; and / or The magnetic multilayer film also includes a buffer layer stacked between the substrate and the heavy metal layer.

6. The magnetic multilayer film according to claim 5, characterized in that, The material of the protective layer is selected from one or more of Ta, silicon dioxide, magnesium oxide, aluminum oxide, tantalum oxide, silicon nitride, aluminum nitride, and titanium nitride; and / or The material of the buffer layer is selected from one or more of Ta, Ti, Zr, and Ru; and / or The thickness of the protective layer is 1-5 nm; and / or The thickness of the buffer layer is 0.5-3 nm.

7. The method for preparing the magnetic multilayer film according to any one of claims 1 to 6, characterized in that, The preparation method includes: sequentially depositing a heavy metal layer, a ferromagnetic layer, a rare earth magnetic alloy layer, a rare earth metal layer, a light metal layer, and a protective coating layer on the substrate using physical vapor deposition.

8. The preparation method according to claim 7, characterized in that, The method further includes: depositing a buffer layer between the substrate and the heavy metal layer; and / or The method further includes: depositing a protective layer over the protective overlay; and / or The physical vapor deposition method is selected from one or more of magnetron sputtering, molecular beam epitaxy, pulsed laser method and electron beam evaporation method.

9. A spintronic device comprising a magnetic multilayer film according to any one of claims 1 to 6 or a magnetic multilayer film prepared by the preparation method according to claim 7 or 8.

10. Use of the magnetic multilayer film according to any one of claims 1 to 6 or the magnetic multilayer film prepared by the preparation method according to claim 7 or 8 in spintronic devices.

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