An electrically controlled magnetic device based on a Ga-based ultraroom-temperature van der Waals ferromagnetic material and a preparation method thereof

Abstract

The application discloses an electrically controlled magnetic device based on Ga-based ultraroom-temperature van der Waals ferromagnetic material and belongs to the technical field of magnetic devices. The Ga-based ultraroom-temperature van der Waals ferromagnetic material, the non-magnetic semiconductor, the Ga-based ultraroom-temperature van der Waals ferromagnetic material and the non-magnetic gate dielectric are sequentially arranged from bottom to top; four electrodes are further included; the first electrode and the second electrode are in contact with the upper Ga-based ultraroom-temperature van der Waals ferromagnetic material respectively; the third electrode is in contact with the lower Ga-based ultraroom-temperature van der Waals ferromagnetic material; and the fourth electrode is in contact with the non-magnetic gate dielectric. The Ga-based ultraroom-temperature van der Waals ferromagnetic material used in the application can realize effective switching of high and low configurations below the Curie temperature (400-800K), and the critical current density is as low as 4A / cm 2 The room-temperature tunneling magnetoresistance of the device can be effectively adjusted by a gate voltage (-20V-20V) or a gate current (-100muA-100muA), and the adjustment range is 30%-300%.

Description

Technical Field

[0001] This invention belongs to the field of magnetic device fabrication technology, and more specifically, relates to an electrically controlled magnetic device based on Ga-based ultra-room temperature van der Waals ferromagnetic material and its fabrication method. Background Technology

[0002] Ferromagnetic materials have broad application prospects in modern life, such as in biomedicine and information storage. However, the development of science and technology has also placed higher demands on ferromagnetic materials and the spintronic devices they constitute. Unlike traditional three-dimensional ferromagnetic materials, two-dimensional van der Waals ferromagnetic materials such as CrI3, Cr2Ge2Te6, and Fe have been discovered in recent years. n GeTe2 (n = 3, 4, 5) and CrTe2 are functional materials that combine van der Waals crystal structure and ferromagnetism. They possess atomically flat two-dimensional surfaces, which facilitates the construction of various van der Waals heterostructures with high-quality interfaces, enabling the realization of novel electrically controlled magnetic devices. These devices hold promise for next-generation memory and computing chips. However, currently known van der Waals ferromagnetic materials either have low Curie temperatures or poor overall ferromagnetic properties at room temperature, making practical applications at room temperature difficult. This drawback severely hinders the development of next-generation low-power, high-performance memory and computing chips based on electrically controlled magnetic devices.

[0003] Our research team previously filed a patent (application publication number CN 115354396 A) disclosing Ga-based van der Waals room-temperature ferromagnetic crystal materials, their preparation, and applications. However, the highest Curie temperature of the Ga-based van der Waals room-temperature ferromagnetic crystal material described in that patent is 367K, which cannot fully meet the requirements of practical applications. Another patent previously filed by our research team (application publication number CN 115867113 A) disclosed a spin-orbit moment device based on a Ga-based two-dimensional ferromagnetic heterojunction and its preparation method; however, the lowest critical current density described in that patent is at least 1×10⁻⁶. 4 A / cm 2 The current devices, while capable of operating at similar scales, still consume significant power and cannot meet the requirements of some applications. Furthermore, their functionality is limited, inconsistent with the structure and function of the devices described in this patent. Therefore, it remains a challenge to fabricate two-dimensional van der Waals ferromagnetic materials with ultra-low power consumption and high saturation magnetization, and to develop novel ultra-low power electrically controlled magnetic devices capable of operating at room temperature based on these materials. Summary of the Invention

[0004] The object of the present invention is to provide an electrically controlled magnetic device based on a Ga-based super-ambient-temperature van der Waals ferromagnetic material to solve the above problems. Using the present invention, a high-performance and low-power-consumption electrically controlled magnetic device can be fabricated. The electrically controlled magnetic device prepared by the present invention is based on a bilayer metal electrode (Cr / Au, Cr / Ag, Cr / Cu, Cr / Al or Cr / Pt), a Ga-based super-ambient-temperature van der Waals ferromagnetic material Fe 3-a Ga b Te c (-4 ≤ a < -2 or 2 < a < 3, 0.01 < b < 3, 0.01 < c < 5) or Fe 5-d Ge e Ga f Te g (2 < d < 5, 0.01 < e < 3, 0.01 < f < 3, 0.01 < g < 5), a non-magnetic semiconductor (hBN, MgO, Al2O3, Sb2O3, Bi2O3, HfO2, Te, TeO2, SeO2, CaF2, Y2O3, LaF3, FeF2, FeF3, BaF2, TiF4, AlF3SnF2 or WS k Se 2-k (where 0 ≤ k ≤ 2), a non-magnetic gate dielectric (hBN, In2Se3, CuInP2S6, In2Te3, Hf x Zr 1-x O2 (where 0 ≤ x ≤ 1), MoS y Se 2-y (where 0 ≤ y ≤ 2) or WS z Se 2-z (where 0 ≤ z ≤ x). The electrically controlled magnetic device prepared according to the invention achieves effective switching between high and low configurations below the Curie temperature (400 - 500 K) of the Ga-based super-ambient-temperature van der Waals ferromagnetic material used, and the critical current density is as low as 4 A / cm 2 order of magnitude, greatly reducing the power consumption by about 4 orders of magnitude; in addition, the room-temperature tunneling magnetoresistance of the electrically controlled magnetic device can be effectively adjusted by the gate voltage (-20 V to 20 V) or the gate current (-100 μA to 100 μA), and the adjustment range is 30% - 300%. The preparation method of the electrically controlled magnetic device based on the Ga-based super-ambient-temperature van der Waals ferromagnetic material described in the present invention has a simple process and good process stability. This invention is expected to promote the development and practical application of low-power storage chips and computing chips with ultra-low current adjustability based on novel Ga-based super-ambient-temperature van der Waals ferromagnetic materials.

[0005] According to a first aspect of the present invention, an electrically controlled magnetic device based on a Ga-based ultra-room temperature van der Waals ferromagnetic material is provided. The electrically controlled magnetic device is a thin-film heterojunction structure comprising, from bottom to top, a Ga-based ultra-room temperature van der Waals ferromagnetic material, a non-magnetic semiconductor, a Ga-based ultra-room temperature van der Waals ferromagnetic material, and a non-magnetic grating dielectric.

[0006] The electrically controlled magnetic device further includes a first electrode, a second electrode, a third electrode, and a fourth electrode; the first electrode and the second electrode are respectively in contact with the upper layer of Ga-based ultra-room temperature van der Waals ferromagnetic material; the third electrode is in contact with the lower layer of Ga-based ultra-room temperature van der Waals ferromagnetic material; the fourth electrode is in contact with a non-magnetic gate dielectric; the first electrode and the second electrode are used to apply pulse current, the first electrode and the fourth electrode are used to adjust the tunneling magnetoresistance of the device by applying gate voltage or gate current, and the first electrode and the third electrode are used to measure voltage.

[0007] Preferably, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe. 3-a Ga b Te c or Fe 5-d Ge e Ga f Te g Where -4≤a<-2 or 2 <a<3,0.01<b<3,0.01<c<5,2<d<5,0.01<e<3,0.01<f<3,0.01<g<5。

[0008] Preferably, the Fe 3-a Ga b Te c Ferromagnetic materials and the Fe 5-d Ge e Ga f Te g The Curie temperature of ferromagnetic materials is 400–800 K, and the Fe... 3-a Ga b Te c Ferromagnetic materials and the Fe 5-d Ge e Ga f Te g Ferromagnetic materials exhibit ferromagnetism below their respective Curie temperatures.

[0009] Preferably, the non-magnetic semiconductor is hBN, MgO, Al2O3, Sb2O3, Bi2O3, HfO2, Te, TeO2, SeO2, CaF2, Y2O3, LaF3, FeF2, FeF3, BaF2, TiF4, AlF3, SnF2, or WS. k Se 2-k (where 0 ≤ k ≤ 2).

[0010] Preferably, the non-magnetic grating medium is hBN, In2Se3, CuInP2S6, In2Te3, or Hf. x Zr 1-x O2 (where 0 ≤ x ≤ 1), MoS y Se 2-y (where 0 ≤ y ≤ 2) or WS z Se 2-z (where 0 ≤ z ≤ 2).

[0011] Preferably, the first electrode, the second electrode, the third electrode, and the fourth electrode are double-layer electrodes, each independently selected from chromium-gold double-layer electrodes, chromium-silver double-layer electrodes, chromium-copper double-layer electrodes, chromium-aluminum double-layer electrodes, or chromium-platinum double-layer electrodes.

[0012] According to another aspect of the present invention, a method for preparing any one of the electrically controlled magnetic devices is provided, comprising the following steps:

[0013] (1) The pattern of the third electrode is drawn on an insulating substrate using photolithography;

[0014] (2) Deposit the third electrode on the electrode pattern obtained in step (1), and then peel off the third electrode;

[0015] (3) Ga-based ultra-room temperature van der Waals ferromagnetic material, non-magnetic semiconductor, Ga-based ultra-room temperature van der Waals ferromagnetic material and non-magnetic gate dielectric are sequentially covered on the fabricated third electrode;

[0016] (4) The patterns of the first electrode, the second electrode and the fourth electrode are drawn on the thin film heterojunction obtained in step (3) using photolithography.

[0017] (5) The first electrode, the second electrode and the fourth electrode are deposited on the electrode pattern obtained in step (4), and then the first electrode, the second electrode and the fourth electrode are peeled off to obtain the electrically controlled magnetic device based on Ga-based ultra-room temperature van der Waals ferromagnetic material.

[0018] Preferably, the covering method is chemical vapor transport, chemical vapor deposition, molecular beam epitaxy, magnetron sputtering, or thermal evaporation.

[0019] Preferably, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe. 3-a Ga b Te c or Fe 5-d Ge e Ga f Te gWhere -4≤a<-2 or 2 <a<3,0.01<b<3,0.01<c<5,2<d<5,0.01<e<3,0.01<f<3,0.01<g<5。

[0020] In summary, compared with the prior art, the above-described technical solutions conceived by this invention mainly possess the following technical advantages:

[0021] (1) The electrically controlled magnetic device based on Ga-based ultra-room temperature van der Waals ferromagnetic material of the present invention can achieve effective switching between high and low configurations below the Curie temperature (400-500K) of the Ga-based ultra-room temperature van der Waals ferromagnetic material used, with a critical current density of 10 3 ~10 4 A / cm 2 The magnitude is lower than the critical current density required for most known electrically controlled magnetization reversals.

[0022] (2) The Fe of the present invention 3-a Ga b Te c Fe ferromagnetic materials 3-a Ga b Te c The compound and the Fe 5-d Ge e Ga f Te g Fe ferromagnetic materials 5-d Ge e Ga f Te g All compounds contain iron atoms with a valence of zero and strong spin exchange coupling of up to 0.07 eV between iron atoms.

[0023] (3) The tunneling magnetoresistance of an electrically controlled magnetic device based on Ga-based ultra-room temperature van der Waals ferromagnetic material of the present invention can be effectively controlled at room temperature by gate voltage (-20V to 20V) or gate current (-100μA to 100μA), with a control range of 30% to 300%, and the highest value is higher than the tunneling magnetoresistance of all known van der Waals magnetic tunnel junctions.

[0024] (4) The total thickness of the electrically controlled magnetic device based on Ga-based ultra-room temperature van der Waals ferromagnetic material of the present invention can be 5-500 nm, wherein the thickness of each material layer can be arbitrarily adjusted. Attached Figure Description

[0025] Figure 1 This is a simplified diagram of the device structure of an electrically controlled magnetic device based on Ga-based ultra-room temperature van der Waals ferromagnetic material, as described in Example 1.

[0026] Figure 2This is the tunneling magnetoresistance curve of an electrically controlled magnetic device based on Ga-based ultra-room temperature van der Waals ferromagnetic material in Example 2, at room temperature, zero gate voltage, and 100 μA gate current. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of the invention described below can be combined with each other as long as they do not conflict with each other. This invention provides the fabrication of an electrically controlled magnetic device based on Ga-based ultra-room temperature van der Waals ferromagnetic material. The fabrication method of the device is as follows:

[0028] (1) Spin-coat photoresist onto the substrate and bake it at a certain temperature for a period of time;

[0029] (2) The pattern of electrode 3 for electronically controlled magnetic devices is drawn using photolithography.

[0030] (3) A double-layer metal electrode is deposited on the pattern of electrode 3 by means of an electron beam evaporation system;

[0031] (4) Rinse the electrode with an organic solvent and then peel off electrode 3;

[0032] (5) Ga-based ultra-low temperature van der Waals ferromagnetic material, non-magnetic semiconductor, Ga-based ultra-low temperature van der Waals ferromagnetic material and non-magnetic grid dielectric with appropriate thickness are sequentially covered on the prepared electrode 3;

[0033] (6) Repeat step (1) on the obtained thin film heterojunction and use photolithography to draw the patterns of electrode 1, electrode 2 and electrode 4.

[0034] (7) A double-layer metal electrode is deposited on the pattern of electrode 1, electrode 2 and electrode 4 by means of an electron beam evaporation system.

[0035] (8) Use organic solvent to rinse the electrodes, peel off electrode 1, electrode 2 and electrode 4, and make an electrically controlled magnetic device.

[0036] In some embodiments, the substrate includes, but is not limited to, SiO2, Al2O3, GaAs, SiN, and fluorinated mica.

[0037] In some embodiments, the spin coating speed is 500-9000 rpm, and the spin coating duration is 0.5-3 minutes. The baking temperature is 70-170°C, and the baking time is 1-15 minutes.

[0038] In some embodiments, the electrode 1 and the electrode 2 are in contact with the upper-layer Ga-based room-temperature van der Waals ferromagnetic material; the electrode 3 is in contact with the underlying Ga-based room-temperature van der Waals ferromagnetic material; and the electrode 4 is in contact with the non-magnetic gate dielectric.

[0039] In some embodiments, for the four bilayer metal electrodes, a pulsed current is applied through the electrode 1 and the electrode 2, and a gate voltage or a gate current is applied through the electrode 1 and the electrode 4 to regulate the tunneling magnetoresistance of the device, and a voltage is measured through the electrode 1 and the electrode 3.

[0040] In some embodiments, the bilayer metal electrode is Cr / Au, Cr / Ag, Cr / Cu, Cr / Al, or Cr / Pt.

[0041] In some embodiments, the organic solvent used for rinsing the electrode is acetone.

[0042] In some embodiments, the Ga-based room-temperature van der Waals ferromagnetic material is Fe 3-a Ga b Te c (-4 ≤ a < -2 or 2 < a < 3, 0.01 < b < 3, 0.01 < c < 5) or Fe 5-d Ge e Ga f Te g (2 < d < 5, 0.01 < e < 3, 0.01 < f < 3, 0.01 < g < 5);

[0043] In some embodiments, the non-magnetic semiconductor is hBN, MgO, Al2O3, Sb2O3, Bi2O3, HfO2, Te, TeO2, SeO2, CaF2, Y2O3, LaF3, FeF2, FeF3, BaF2, TiF4, AlF3, SnF2, or WS k Se 2-k (where 0 ≤ k ≤ 2).

[0044] In some embodiments, the non-magnetic gate dielectric is hBN, In2Se3, CuInP2S6, In2Te3, Hf x Zr 1-x O2 (where 0 ≤ x ≤ 1), MoS y Se 2-y (where 0 ≤ y ≤ 2) or WS z Se 2-z (where 0 ≤ z ≤ 2).

[0045] In some embodiments, the total thickness of the electro-controlled magnetic device is 5 - 500 nm, and the thickness of each material layer can be adjusted arbitrarily.

[0046] In some embodiments, a Ga-based van der Waals ferromagnetic material with a suitable thickness, a non-magnetic semiconductor, a Ga-based van der Waals ferromagnetic material, and a non-magnetic gate dielectric are successively covered on the fabricated electrode 3. The specific methods include chemical vapor transport, chemical vapor deposition, molecular beam epitaxy, magnetron sputtering, or thermal evaporation.

[0047] A method for preparing an electrically controlled magnetic device based on a Ga-based van der Waals ferromagnetic material according to the present invention. The electrically controlled magnetic device includes four double-layer metal electrodes (denoted as 1, 2, 3, 4) and a thin film heterojunction composed of a Ga-based van der Waals ferromagnetic material, a non-magnetic semiconductor, a Ga-based van der Waals ferromagnetic material, and a non-magnetic gate dielectric from bottom to top. The double-layer metal electrodes are Cr / Au, Cr / Ag, Cr / Cu, Cr / Al, or Cr / Pt. The Ga-based van der Waals ferromagnetic material is Fe 3-a Ga b Te c (-4 ≤ a < -2 or 2 < a < 3, 0.01 < b < 3, 0.01 < c < 5) or Fe 5-d Ge e Ga f Te g (2 < d < 5, 0.01 < e < 3, 0.01 < f < 3, 0.01 < g < 5). The non-magnetic semiconductor is hBN, MgO, Al2O3, Sb2O3, Bi2O3, HfO2, Te, TeO2, SeO2, CaF2, Y2O3, LaF3, FeF2, FeF3, BaF2, TiF4, AlF3, SnF2, or WS k Se 2-k (where 0 ≤ k ≤ 2). The non-magnetic gate dielectric is hBN, In2Se3, CuInP2S6, In2Te3, Hf x Zr 1-x O2 (where 0 ≤ x ≤ 1), MoS y Se 2-y (where 0 ≤ y ≤ 2) or WS z Se 2-z (where 0 ≤ z ≤ 2). It is made into a two-dimensional form by including chemical vapor transport, chemical vapor deposition, molecular beam epitaxy, magnetron sputtering, or thermal evaporation. [[ID=​​​This invention relates to an electrically controlled magnetic device based on Ga-based ultra-room temperature van der Waals ferromagnetic material. The invention will now be further described in detail with reference to the following specific embodiments and accompanying drawings.

[0050] Example 1

[0051] (1) Spin-coat photoresist on a SiO2 substrate at a speed of 4000 rpm for 1 minute and bake at 100°C for 7 minutes;

[0052] (2) The pattern of electrode 3 for electronically controlled magnetic devices is drawn using photolithography.

[0053] (3) Using an electron beam evaporation system, 10 nm Cr and 10 nm Au electrodes are sequentially deposited on the pattern of electrode 3;

[0054] (4) Rinse the electrode with acetone and then peel off the Cr / Au double metal electrode 3;

[0055] (5) Sequentially adding Ga-based ultra-low temperature room temperature van der Waals ferromagnetic material Fe7Ga with appropriate thickness 0.011 Te 0.011 (5nm thickness), non-magnetic semiconductor WSe2 (1nm thickness), Ga-based ultra-room temperature van der Waals ferromagnetic material Fe7Ga 0.011 Te 0.011 A 5nm thick non-magnetic grating dielectric hBN (5nm thick) is applied to the fabricated electrode 3;

[0056] (6) Repeat step (1) on the obtained thin film heterojunction and use photolithography to draw the patterns of electrode 1, electrode 2 and electrode 4.

[0057] (7) Using an electron beam evaporation system, 10 nm Cr and 10 nm Au electrodes are sequentially deposited on the patterns of electrode 1, electrode 2 and electrode 4;

[0058] (8) Use acetone to rinse the electrodes and peel off Cr / Au double-layer metal electrode 1, Cr / Au double-layer metal electrode 2 and Cr / Au double-layer metal electrode 4 to make an electrically controlled magnetic device.

[0059] Example 2

[0060] Similar to Example 1, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe 5.001 Ga 1.5 Te 2.5 The non-magnetic semiconductor is WSSe, and the non-magnetic gate dielectric is In2Se3.

[0061] Example 3

[0062] Similar to Example 1, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe 0.999Ga 2.999 Te 4.999 The non-magnetic semiconductor is WS2, and the non-magnetic gate dielectric is CuInP2S6.

[0063] Example 4

[0064] Similar to Example 1, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe 0.001 Ga 0.011 Te 0.011 The non-magnetic semiconductor is hBN, and the non-magnetic gate dielectric is In2Te3.

[0065] Example 5

[0066] Same as in Example 1, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe6Ga 1.5 Te 2.5 The non-magnetic semiconductor is MgO, and the non-magnetic gate dielectric is ZrO2.

[0067] Example 6

[0068] Similar to Example 1, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe 0.5 Ga 2.999 Te 4.999 The non-magnetic semiconductor is Al2O3, and the non-magnetic gate dielectric is Hf. 0.5 Zr 0.5 O2.

[0069] Example 7

[0070] Similar to Example 1, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe 2.999 Ge 0.011 Ga 0.011 Te 0.011 The non-magnetic semiconductor is Sb2O3, and the non-magnetic gate dielectric is HfO2.

[0071] Example 8

[0072] Similar to Example 1, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe 0.001 Ge 1.5 Ga 1.5 Te 2.5 The non-magnetic semiconductor is Bi2O3, and the non-magnetic gate dielectric is MoS2.

[0073] Example 9

[0074] Similar to Example 1, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe 1.5 Ge 2.999 Ga 2.999 Te 4.999 The non-magnetic semiconductor is HfO2, and the non-magnetic gate dielectric is WS2.

[0075] Example 10

[0076] Similar to Example 1, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe 1.5 Ge 2.999 Ga 2.999 Te 4.999 The non-magnetic semiconductor is Te, and the non-magnetic gate dielectric is MoSe2.

[0077] Example 11

[0078] Similar to Example 1, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe 1.5 Ge 2.999 Ga 2.999 Te 4.999 The non-magnetic semiconductor is TeO2, and the non-magnetic gate dielectric is WSe2.

[0079] Example 12

[0080] Similar to Example 1, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe 1.5 Ge 2.999 Ga 2.999 Te 4.999 The non-magnetic semiconductor is SeO2, and the non-magnetic gate dielectric is MoWS2.

[0081] Example 13

[0082] Similar to Example 1, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe 1.5 Ge 2.999 Ga 2.999 Te 4.999 The non-magnetic semiconductor is CaF2, and the non-magnetic gate dielectric is MoWSe2.

[0083] Example 14

[0084] Similar to Example 1, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe 1.5 Ge 2.999 Ga 2.999 Te 4.999 The non-magnetic semiconductor is Y2O3, and the non-magnetic gate dielectric is HfO2.

[0085] Example 15

[0086] Similar to Example 1, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe 1.5 Ge 2.999 Ga 2.999 Te 4.999 The non-magnetic semiconductor is LaF3, and the non-magnetic gate dielectric is HfO2.

[0087] Example 16

[0088] Similar to Example 1, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe 1.5 Ge 2.999 Ga 2.999 Te 4.999 The non-magnetic semiconductor is FeF2, and the non-magnetic gate dielectric is HfO2.

[0089] Example 17

[0090] Similar to Example 1, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe 1.5 Ge 2.999 Ga 2.999 Te 4.999 The non-magnetic semiconductor is FeF3, and the non-magnetic gate dielectric is HfO2.

[0091] Example 18

[0092] Similar to Example 1, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe 1.5 Ge 2.999 Ga 2.999 Te 4.999 The non-magnetic semiconductor is BaF2, and the non-magnetic gate dielectric is HfO2.

[0093] Example 19

[0094] Similar to Example 1, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe 1.5 Ge 2.999 Ga 2.999 Te 4.999 The non-magnetic semiconductor is TiF4, and the non-magnetic gate dielectric is HfO2.

[0095] Example 20

[0096] Similar to Example 1, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe 1.5 Ge 2.999 Ga 2.999 Te 4.999 The non-magnetic semiconductor is AlF3, and the non-magnetic gate dielectric is HfO2.

[0097] Example 21

[0098] Similar to Example 1, the Ga-based ultra-room temperature van der Waals ferromagnetic material is Fe 1.5 Ge 2.999 Ga 2.999 Te 4.999 The non-magnetic semiconductor is SnF2, and the non-magnetic gate dielectric is HfO2.

[0099] Figure 1This is a simplified structural diagram of an electrically controlled magnetic device based on Ga-based ultra-low temperature van der Waals ferromagnetic material, as described in Example 1. As shown in the diagram, the electrically controlled magnetic device consists of four double-layer metal electrodes (denoted as 1, 2, 3, 4) and thin-film heterostructures, from bottom to top, consisting of Ga-based ultra-low temperature van der Waals ferromagnetic material, a non-magnetic semiconductor, Ga-based ultra-low temperature van der Waals ferromagnetic material, and a non-magnetic gate dielectric. Electrodes 1 and 2 are in contact with the upper Ga-based ultra-low temperature van der Waals ferromagnetic material; electrode 3 is in contact with the lower Ga-based ultra-low temperature van der Waals ferromagnetic material; and electrode 4 is in contact with the non-magnetic gate dielectric. During measurement, a pulsed current is applied through electrodes 1 and 2, and a gate voltage or gate current is applied through electrodes 1 and 4 to adjust the tunneling magnetoresistance of the device. The voltage is measured through electrodes 1 and 3.

[0100] Figure 2 This is the tunneling magnetoresistance curve of an electrically controlled magnetic device based on a Ga-based ultra-room-temperature van der Waals ferromagnetic material, as described in Example 2, at room temperature, zero gate voltage, and a gate current of 100 μA. As shown in the figure, the device exhibits a low resistance as low as 4 A / cm². 2 It has a critical current density and a tunneling magnetoresistance of up to 170%.

[0101] Table 1 shows the chemical formulas and Curie temperatures of nine Ga-based ultra-room temperature van der Waals ferromagnetic materials with different elemental ratios from Examples 1-9. As can be seen from the table, the novel Ga-based ultra-room temperature van der Waals ferromagnetic materials exhibit Curie temperatures as high as 400–800 K, and electrically controlled magnetic devices made from these ferromagnetic materials can operate below their Curie temperatures.

[0102] Table 1

[0103] Example Chemical formula Curie temperature (K) 1 <![CDATA[Fe7Ga 0.011 The 0.011 ]]> 800 2 <![CDATA[Fe 5.001 Yes 1.5 The 2.5 ]]> 660 3 <![CDATA[Fe 0.999 Yes 2.999 The 4.999 ]]> 430 4 <![CDATA[Fe 0.001 Yes 0.011 The 0.011 ]]> 400 5 <![CDATA[Fe6Ga 1.5 The 2.5 ]]> 750 6 <![CDATA[Fe 0.5 Yes 2.999 The 4.999 ]]> 420 7 <![CDATA[Fe 2.999 Ge 0.011 Ga 0.011 Te 0.011 ]]> 560 8 <![CDATA[Fe 0.001 Ge 1.5 Ga 1.5 Te 2.5 ]]> 400 9 <![CDATA[Fe 1.5 Ge 2.999 Ga 2.999 Te 4.999 ]]> 430

[0104] Table 2 shows the device performance parameters of an electrically controlled magnetic device based on Ga-based ultra-room-temperature van der Waals ferromagnetic material in Examples 1-21 at room temperature, under different gate voltages and gate currents, mainly including critical current density and tunneling magnetoresistance. As shown in the table, at room temperature, the minimum critical current density in the 21 examples is 4 A / cm². 2 The maximum tunneling magnetoresistance is 300%, which is significantly better than existing devices. Furthermore, the tunneling magnetoresistance of the electrically controlled magnetic device based on Ga-based ultra-room-temperature van der Waals ferromagnetic material at room temperature can be effectively controlled by the gate voltage (-20V to 20V) or the gate current (-100μA to 100μA), with a controllable range of 30% to 300%.

[0105] Table 2

[0106]

[0107]

[0108] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An electrically controlled magnetic device based on Ga-based ultra-room temperature van der Waals ferromagnetic material, characterized in that, The electrically controlled magnetic device is a thin-film heterojunction structure, comprising, from bottom to top, Ga-based ultra-room temperature van der Waals ferromagnetic material, non-magnetic semiconductor, Ga-based ultra-room temperature van der Waals ferromagnetic material and non-magnetic grating dielectric; The electrically controlled magnetic device further includes a first electrode, a second electrode, a third electrode, and a fourth electrode; the first electrode and the second electrode are respectively in contact with the upper layer of Ga-based ultra-room temperature van der Waals ferromagnetic material; the third electrode is in contact with the lower layer of Ga-based ultra-room temperature van der Waals ferromagnetic material; the fourth electrode is in contact with a non-magnetic gate dielectric; the first electrode and the second electrode are used to apply pulse current, the first electrode and the fourth electrode are used to adjust the tunneling magnetoresistance of the device by applying gate voltage or gate current, and the first electrode and the third electrode are used to measure voltage; The Ga-based ultra-temperature room temperature van der Waals ferromagnetic material is Fe. 3-a Ga b Te c or Fe 5-d Ge e Ga f Te g Where -4≤a<-2 or 2 <a<3,0.01<b<3,0.01<c<5,2<d<5,0.01<e<3,0.01<f<3,0.01<g<5。 2. The electrically controlled magnetic device based on Ga-based ultra-room temperature van der Waals ferromagnetic material as described in claim 1, characterized in that, The Fe 3-a Ga b Te c Ferromagnetic materials and the Fe 5-d Ge e Ga f Te g The Curie temperature of ferromagnetic materials is 400~800 K, and the Fe... 3-a Ga b Te c Ferromagnetic materials and the Fe 5-d Ge e Ga f Te g Ferromagnetic materials exhibit ferromagnetism below their respective Curie temperatures.

3. The electrically controlled magnetic device based on Ga-based ultra-room temperature van der Waals ferromagnetic material as described in claim 1, characterized in that, The non-magnetic semiconductor is hBN, MgO, Al2O3, Sb2O3, Bi2O3, HfO2, Te, TeO2, SeO2, CaF2, Y2O3, LaF3, FeF2, FeF3, BaF2, TiF4, AlF3, SnF2, or WS. k Se 2-k , where 0≤k≤2.

4. The electrically controlled magnetic device based on Ga-based ultra-room temperature van der Waals ferromagnetic material as described in claim 1, characterized in that, The non-magnetic grating medium is hBN, In2Se3, CuInP2S6, In2Te3, Hf x Zr 1-x O2, MoS y Se 2-y or WS z Se 2-z , where 0≤x≤1, 0≤y≤2, 0≤z≤2.

5. The electrically controlled magnetic device based on Ga-based ultra-room temperature van der Waals ferromagnetic material as described in claim 1, characterized in that, The first electrode, the second electrode, the third electrode, and the fourth electrode are double-layer electrodes, each independently selected from chromium-gold double-layer electrodes, chromium-silver double-layer electrodes, chromium-copper double-layer electrodes, chromium-aluminum double-layer electrodes, or chromium-platinum double-layer electrodes.

6. The method for preparing an electrically controlled magnetic device according to any one of claims 1-5, characterized in that, Includes the following steps: (1) The pattern of the third electrode is drawn on an insulating substrate using photolithography; (2) Deposit the third electrode onto the electrode pattern obtained in step (1), and then peel off the third electrode; (3) Ga-based ultra-room temperature van der Waals ferromagnetic material, non-magnetic semiconductor, Ga-based ultra-room temperature van der Waals ferromagnetic material and non-magnetic gate dielectric are sequentially covered on the fabricated third electrode; (4) The patterns of the first electrode, the second electrode and the fourth electrode are drawn on the thin film heterojunction obtained in step (3) using photolithography. (5) The first electrode, the second electrode and the fourth electrode are deposited on the electrode pattern obtained in step (4), and then the first electrode, the second electrode and the fourth electrode are peeled off to obtain the electrically controlled magnetic device based on Ga-based ultra-room temperature van der Waals ferromagnetic material.

7. The preparation method according to claim 6, characterized in that, The covering method is chemical vapor transport, chemical vapor deposition, molecular beam epitaxy, magnetron sputtering, or thermal evaporation.

8. The preparation method according to claim 6, characterized in that, The Ga-based ultra-temperature room temperature van der Waals ferromagnetic material is Fe. 3- a Ga b Te c or Fe 5-d Ge e Ga f Te g Where -4≤a<-2 or 2 <a<3,0.01<b<3,0.01<c<5,2<d<5,0.01<e<3,0.01<f<3,0.01<g<5。

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