Electric control magnetic device based on Ga-based super-room-temperature Van der Waals ferromagnetic material and preparation method

Abstract

The invention discloses an electric control magnetic device based on a Ga-based super-room-temperature Van der Waals ferromagnetic material, and belongs to the technical field of magnetic devices. Comprising a Ga-based super-room-temperature Van der Waals ferromagnetic material, a non-magnetic semiconductor, a Ga-based super-room-temperature Van der Waals ferromagnetic material and a non-magnetic gate medium from bottom to top, the device further comprises four electrodes. The first electrode and the second electrode are respectively in contact with the upper layer Ga-based super-room-temperature van der Waals ferromagnetic material; the third electrode is in contact with the Ga-based super-room-temperature van der Waals ferromagnetic material on the lower layer; and the fourth electrode is in contact with the non-magnetic gate medium. Effective switching of high and low configurations is realized under the Curie temperature (400-800K) of the Ga-based super-room-temperature Van der Waals ferromagnetic material, and the critical current density is as low as 4A / cm < 2 > magnitude; the room temperature tunneling magnetoresistance of the device can be effectively adjusted by the gate voltage (-20V to 20V) or the gate current (-100mu A to 100mu A), and the adjustment amplitude is 30% to 300%.

Description

Technical Field

[0001] The present invention belongs to the technical field of magnetic device preparation, and more specifically, relates to an electrically controlled magnetic device based on Ga-based ultra-room temperature van der Waals ferromagnetic material and a preparation method thereof. Background Art

[0002] Ferromagnetic materials have a wide range of application prospects in modern life, such as biomedicine and information storage. However, the development of science and technology has also put forward higher requirements for ferromagnetic materials and the spin electronic devices they constitute. Different from traditional three-dimensional ferromagnetic materials, the two-dimensional van der Waals ferromagnetic materials discovered in recent years, such as CrI3, Cr2Ge2Te6, Fe n GeTe2 (n=3,4,5) and CrTe2 are functional materials that have both van der Waals crystal structure and ferromagnetism. They have atomically flat two-dimensional surfaces, which are conducive to the construction of various van der Waals heterostructures with high-quality interfaces, thereby realizing various new electrically controlled magnetic devices, which are expected to be used in the next generation of memory chips and computing chips. However, the currently known van der Waals ferromagnetic materials either have a low Curie temperature or poor comprehensive ferromagnetic properties at room temperature, making them difficult to be used in practical applications at room temperature. This shortcoming seriously hinders the development of the next generation of low-power, high-performance memory chips and computing chips based on electrically controlled magnetic devices.

[0003] The patent previously applied by our research team (application publication number CN 115354396 A) discloses Ga-based van der Waals room temperature ferromagnetic crystal materials, preparation and applications. However, the highest Curie temperature of the Ga-based van der Waals room temperature ferromagnetic crystal materials described in the patent is 367K, which cannot fully meet the needs of practical applications. Another patent previously applied by our research team (application publication number CN 115867113 A) discloses a spin-orbit torque device based on Ga-based two-dimensional ferromagnetic heterojunction and its preparation method. However, the minimum critical current density described in the patent is as low as 1×10 4 A / cm 2 The power consumption is still high and cannot meet the requirements of some applications, and the device function is single, which is inconsistent with the device structure and function described in this patent. It can be seen that it is still a challenge to prepare two-dimensional van der Waals ferromagnetic materials with super-room Curie temperature and large saturation magnetization, and to realize new ultra-low power consumption electrically controlled magnetic devices that can work at room temperature based on them. Summary of the invention

[0004] The object of the present invention is to provide an electrically controlled magnetic device based on a Ga-based room-temperature van der Waals ferromagnetic material to solve the above problems. Using the present invention, a high-performance and low-power electrically controlled magnetic device can be prepared. The electrically controlled magnetic device prepared by the present invention is based on a double-layer metal electrode (Cr / Au, Cr / Ag, Cr / Cu, Cr / Al or Cr / Pt), a Ga-based room-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 ≤ 2). The electrically controlled magnetic device prepared according to the invention realizes effective switching between high and low configurations below the Curie temperature (400 - 500 K) of the used Ga-based room-temperature van der Waals ferromagnetic material, 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 regulated by the gate voltage (-20 V to 20 V) or the gate current (-100 μA to 100 μA), and the regulation range is 30% - 300%. The preparation method of the electrically controlled magnetic device based on the Ga-based room-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 new Ga-based room-temperature van der Waals ferromagnetic materials.

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

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

[0007] Preferably, the Ga-based super-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 400-800K. 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, 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 a chromium-gold double-layer electrode, a chromium-silver double-layer electrode, a chromium-copper double-layer electrode, a chromium-aluminum double-layer electrode or a chromium-platinum double-layer electrode.

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

[0013] (1) drawing a pattern of the third electrode on the insulating substrate using photolithography technology;

[0014] (2) vapor-depositing a third electrode on the electrode pattern obtained in step (1), and then peeling off the third electrode;

[0015] (3) sequentially covering the Ga-based super-room-temperature van der Waals ferromagnetic material, the non-magnetic semiconductor, the Ga-based super-room-temperature van der Waals ferromagnetic material, and the non-magnetic grating medium on the manufactured third electrode;

[0016] (4) drawing patterns of the first electrode, the second electrode, and the fourth electrode on the thin film heterojunction obtained in step (3) using photolithography technology;

[0017] (5) Vapor-depositing a first electrode, a second electrode and a fourth electrode on the electrode pattern obtained in step (4), and then peeling off the first electrode, the second electrode and the fourth electrode, thereby obtaining the electrically controlled magnetic device based on the Ga-based super-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 super-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。

[0020] In general, the above technical solution conceived by the present invention has the following technical advantages compared with the prior art:

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

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

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

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

[0025] Figure 1 This is a simplified diagram of the device structure of an electrically controlled magnetic device based on a Ga-based super-room temperature van der Waals ferromagnetic material according to Example 1.

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

[0027] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other. The present invention provides a method for preparing an electrically controlled magnetic device based on a Ga-based ultra-room temperature van der Waals ferromagnetic material, and the method for preparing the device is as follows

[0028] (1) Spin-coating a photoresist on a substrate and baking it at a certain temperature for a period of time;

[0029] (2) using photolithography technology to draw a pattern of the electrode 3 for the electrically controlled magnetic device;

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

[0031] (4) rinsing the electrode with an organic solvent, and then peeling off the electrode 3;

[0032] (5) sequentially covering the prepared electrode 3 with a Ga-based super-room-temperature van der Waals ferromagnetic material, a non-magnetic semiconductor, a Ga-based super-room-temperature van der Waals ferromagnetic material, and a non-magnetic grating medium having a suitable thickness;

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

[0034] (7) vapor-depositing a double-layer metal electrode on the patterns of electrode 1, electrode 2, and electrode 4 by means of an electron beam evaporation system;

[0035] (8) The electrodes are rinsed with an organic solvent to peel off the electrodes 1, 2 and 4 to produce an electrically controlled magnetic device.

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

[0037] In some embodiments, the spin coating speed is 500-9000 rpm, 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 double-layer 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 the voltage is measured through the electrode 1 and the electrode 3.

[0040] In some embodiments, the double-layer 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 electrically 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 sequentially 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. The electrically controlled magnetic device includes four bilayer 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 bilayer 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.

[0048] The function of an electrically controlled magnetic device based on a Ga-based van der Waals ferromagnetic material of the present invention is as follows: When a certain fixed value of gate voltage or gate current is applied to the non-magnetic gate dielectric, a pulsed current flows through the upper Ga-based van der Waals ferromagnetic material, thereby driving its magnetization reversal, and thus causing a change in the tunneling magnetoresistance of the device.

[0049] The present invention is an electrically controlled magnetic device based on a Ga-based super-room temperature van der Waals ferromagnetic material. The present invention is now further described in detail in conjunction with the following specific embodiments and drawings.

[0050] Example 1

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

[0052] (2) using photolithography technology to draw a pattern of the electrode 3 for the electrically controlled magnetic device;

[0053] (3) using an electron beam evaporation system to sequentially deposit 10 nm Cr and 10 nm Au electrodes on the pattern of electrode 3;

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

[0055] (5) Sequentially add Ga-based super room temperature van der Waals ferromagnetic material Fe7Ga 0.011 Te 0.011 (thickness 5nm), non-magnetic semiconductor WSe2 (thickness 1nm), Ga-based super room temperature van der Waals ferromagnetic material Fe7Ga 0.011 Te 0.011 (thickness 5nm) and non-magnetic grating medium hBN (thickness 5nm) are covered on the fabricated electrode 3;

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

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

[0059] Example 2

[0060] Same as in Example 1, the Ga-based super 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 medium is In2Se3.

[0061] Example 3

[0062] Same as in Example 1, the Ga-based super 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 medium is CuInP2S6.

[0063] Example 4

[0064] Same as in Example 1, the Ga-based super 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 medium is In2Te3.

[0065] Example 5

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

[0067] Example 6

[0068] Same as in Example 1, the Ga-based super 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 grating medium is Hf 0.5 Zr 0.5 O2.

[0069] Example 7

[0070] Same as in Example 1, the Ga-based super 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 medium is HfO2.

[0071] Example 8

[0072] Same as in Example 1, the Ga-based super 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 medium is MoS2.

[0073] Example 9

[0074] Same as in Example 1, the Ga-based super 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 grating medium is WS2.

[0075] Example 10

[0076] Same as in Example 1, the Ga-based super 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 medium is MoSe2.

[0077] Embodiment 11

[0078] Same as in Example 1, the Ga-based super 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 medium is WSe2.

[0079] Example 12

[0080] Same as in Example 1, the Ga-based super 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 grating medium is MoWS2.

[0081] Example 13

[0082] Same as in Example 1, the Ga-based super 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 medium is MoWSe2.

[0083] Embodiment 14

[0084] Same as in Example 1, the Ga-based super 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 grating medium is HfO2.

[0085] Embodiment 15

[0086] Same as in Example 1, the Ga-based super 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 grating medium is HfO2.

[0087] Example 16

[0088] Same as in Example 1, the Ga-based super 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 grating medium is HfO2.

[0089] Embodiment 17

[0090] Same as in Example 1, the Ga-based super 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 grating medium is HfO2.

[0091] Embodiment 18

[0092] Same as in Example 1, the Ga-based super 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 medium is HfO2.

[0093] Embodiment 19

[0094] Same as in Example 1, the Ga-based super 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 medium is HfO2.

[0095] Embodiment 20

[0096] Same as in Example 1, the Ga-based super 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 medium is HfO2.

[0097] Embodiment 21

[0098] Same as in Example 1, the Ga-based super 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 medium is HfO2.

[0099] Figure 1This is a schematic diagram of the device structure of an electrically controlled magnetic device based on a Ga-based super-room-temperature van der Waals ferromagnetic material in Example 1. As can be seen from the figure, the electrically controlled magnetic device is composed of four double-layer metal electrodes (denoted as 1, 2, 3, and 4) and thin film heterostructures of Ga-based super-room-temperature van der Waals ferromagnetic material, non-magnetic semiconductor, Ga-based super-room-temperature van der Waals ferromagnetic material, and non-magnetic grating medium from bottom to top; wherein, electrode 1 and electrode 2 are in contact with the upper layer of Ga-based super-room-temperature van der Waals ferromagnetic material; the electrode 3 is in contact with the lower Ga-based super-room-temperature van der Waals ferromagnetic material; the electrode 4 is in contact with the non-magnetic grating medium; during measurement, a pulse current is applied through electrode 1 and electrode 2, a gate voltage or gate current is applied through electrode 1 and electrode 4 to control the tunneling magnetoresistance of the device, and the voltage is measured through electrode 1 and electrode 3.

[0100] Figure 2 This is the tunneling magnetoresistance curve of an electrically controlled magnetic device based on Ga-based super-room temperature van der Waals ferromagnetic material in Example 2 at room temperature, zero gate voltage and 100μA gate current. As can be seen from the figure, the device exhibits a low resistance of 4A / cm 2 The critical current density and tunneling magnetoresistance are as high as 170%.

[0101] Table 1 shows the chemical formula and Curie temperature of 9 Ga-based super-room temperature van der Waals ferromagnetic materials with different element ratios in Examples 1 to 9. As can be seen from the table, the novel Ga-based super-room temperature van der Waals ferromagnetic material has a Curie temperature as high as 400 to 800 K, and the electrically controlled magnetic device made of the ferromagnetic material can work below its Curie temperature.

[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 super-room temperature van der Waals ferromagnetic materials at room temperature, different gate voltages and gate currents of Examples 1-21, mainly including critical current density and tunneling magnetoresistance. It can be seen from the table that at room temperature, the minimum critical current density of the 21 examples is 4A / cm 2 , the maximum tunneling magnetoresistance is 300%, which is much better than the existing devices. In addition, the tunneling magnetoresistance of the electrically controlled magnetic device based on Ga-based super room temperature van der Waals ferromagnetic materials at room temperature can be effectively regulated by gate voltage (-20V to 20V) or gate current (-100μA to 100μA), and the regulation range is 30% to 300%.

[0105] Table 2

[0106]

[0107]

[0108] It will be easily understood by those skilled in the art that the above description is only 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 in the protection scope of the present invention.

Claims

1. An electrically controlled magnetic device based on Ga-based super-room temperature van der Waals ferromagnetic material, characterized in that: The electrically controlled magnetic device is a thin film heterojunction structure, including Ga-based super room temperature van der Waals ferromagnetic material, non-magnetic semiconductor, Ga-based super room temperature van der Waals ferromagnetic material and non-magnetic grating medium from bottom to top; The electrically controlled magnetic device also 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 Ga-based super-room temperature van der Waals ferromagnetic material; the third electrode is in contact with the lower Ga-based super-room temperature van der Waals ferromagnetic material; the fourth electrode is in contact with the non-magnetic gate medium; the first electrode and the second electrode are used to apply a pulse current, the first electrode and the fourth electrode are used to regulate the tunneling magnetoresistance of the device by applying a gate voltage or a gate current, and the first electrode and the third electrode are used to measure voltage.

2. An electrically controlled magnetic device based on Ga-based super-room temperature van der Waals ferromagnetic material as claimed in claim 1, characterized in that: The Ga-based super-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。 3. An electrically controlled magnetic device based on Ga-based super-room temperature van der Waals ferromagnetic material as claimed in claim 2, 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 400-800K. 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.

4. An electrically controlled magnetic device based on Ga-based super-room temperature van der Waals ferromagnetic material as claimed 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.

5. The electrically controlled magnetic device based on Ga-based super-room temperature van der Waals ferromagnetic material according to 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.

6. An electrically controlled magnetic device based on Ga-based super-room temperature van der Waals ferromagnetic material as claimed 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 a chromium-gold double-layer electrode, a chromium-silver double-layer electrode, a chromium-copper double-layer electrode, a chromium-aluminum double-layer electrode or a chromium-platinum double-layer electrode.

7. The method for preparing an electrically controlled magnetic device according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) drawing a pattern of the third electrode on the insulating substrate using photolithography technology; (2) vapor-depositing a third electrode on the electrode pattern obtained in step (1), and then peeling off the third electrode; (3) sequentially covering the Ga-based super-room-temperature van der Waals ferromagnetic material, the non-magnetic semiconductor, the Ga-based super-room-temperature van der Waals ferromagnetic material, and the non-magnetic grating medium on the manufactured third electrode; (4) drawing patterns of the first electrode, the second electrode, and the fourth electrode on the thin film heterojunction obtained in step (3) using photolithography technology; (5) Vapor-depositing a first electrode, a second electrode and a fourth electrode on the electrode pattern obtained in step (4), and then peeling off the first electrode, the second electrode and the fourth electrode, thereby obtaining the electrically controlled magnetic device based on the Ga-based super-room temperature van der Waals ferromagnetic material.

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

9. The preparation method according to claim 7, characterized in that: The Ga-based super-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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