A method for preparing a single-phase multiferroic electric coupling material based on ion implantation

Abstract

The application relates to a method for preparing a single-phase multi-ferromagnetic electric coupling material based on ion implantation, which comprises implanting Fe 2+ The single-phase multi-ferromagnetic electric coupling material is obtained by implanting methyammonium bromide lead crystals (CH3NH3PbBr3) with ions. 2+ The single-phase multi-ferromagnetic electric coupling material is obtained by irradiating the surface of a methyammonium bromide lead crystal sample with ions, and the material has ferromagnetism and a large dielectric constant, has a strong magnetoelectric coupling effect in a wide temperature range, especially at room temperature, and has a great application potential in the fields of spin electronic devices, multi-state information storage and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of material science, and particularly relates to a method for preparing single-phase multiferroic magnetoelectric coupling material based on ion implantation. BACKGROUND

[0002] Multiferroics refers to a substance containing two or more than two basic ferroelectric characteristics, which include ferroelectricity (antiferroelectricity), ferromagnetism (antiferromagnetism, ferrimagnetism) and ferroelasticity. Magnetoelectric coupling material refers to a material that changes the ferroelectric polarization state or the magnetic state of the material under the action of an external magnetic field or electric field, that is, the magnetic state of the material can be controlled by an electric field or the ferroelectric polarization state of the material can be controlled by an external magnetic field. Such multiferroic materials with both magnetic and electric properties contain two dimensions of spin and charge, and therefore have wide application prospects in the fields of spintronics, multi-state information storage, sensing, etc.

[0003] In recent years, single-phase multiferroic materials as a kind of material with magnetoelectric coupling effect have attracted people's research interest. However, there are very few single-phase multiferroic materials that can realize magnetoelectric coupling effect, especially at room temperature (300K) and above. The current single-phase multiferroic materials can only exhibit obvious magnetoelectric coupling effect at a low temperature of 100K-200K, and the magnetoelectric response is very small. At room temperature and above, only weak magnetoelectric coupling effect is exhibited, or even no magnetoelectric coupling effect is exhibited. This shortcoming makes the magnetoelectric coupling device based on single-phase multiferroic material unable to meet the practical requirements, and limits the application range.

[0004] Therefore, it is the research aspiration of the industry in recent decades to develop a single-phase multiferroic material system with strong magnetoelectric coupling effect at room temperature. SUMMARY

[0005] In view of the deficiencies of the prior art, especially the problem that the current single-phase multiferroic material can only exhibit obvious magnetoelectric coupling effect at a low temperature of 100K-200K, and the magnetoelectric response is very small;

[0006] Based on this, the present application provides a method for preparing single-phase multiferroic magnetoelectric coupling material based on ion implantation. The single-phase multiferroic magnetoelectric coupling material has multiferroicity, and has strong magnetoelectric coupling effect at a wide temperature range, especially at room temperature.

[0007] Term explanation:

[0008] CH3NH3PbBr3: methylamine bromide lead crystal, which can be purchased on the market, or can be prepared according to the prior art.

[0009] CH3NH3Br: Methylamine bromide, which can be purchased commercially or prepared using existing technologies.

[0010] PbBr2: Lead dibromide, commercially available.

[0011] DMF: N,N-Dimethylformamide; N,N-Dimethylformamide, commercially available.

[0012] This invention is achieved through the following technical solution:

[0013] A method for preparing single-phase multiferromagnetic-electric coupling materials based on ion implantation, the method comprising: ion implantation of Fe... 2+ Ion implantation into methylamine lead bromide crystal (CH3NH3PbBr3) yields a single-phase multiferroelectric coupling material.

[0014] Fe 2+ The specific method for ion implantation of methylamine lead bromide crystal (CH3NH3PbBr3) is as follows:

[0015] Fe is used at room temperature or high temperature 2+ Ion irradiation of the surface of methylamine lead bromide crystal sample, with controlled Fe irradiation 2+ The ion-selective dose is 1-5×10 16～17 ion / cm 2 The accelerating voltage is 300-400 keV, Fe 2+ Ion implantation is achieved with ion energies of 1-4 MeV and average atomic displacement energies of 25-35 eV.

[0016] According to a preferred embodiment of the present invention, Fe is used at room temperature. 2+ When the surface of a methylamine lead bromide crystal sample is irradiated with ions, Fe 2+ The ion-selective dose is 1-4 × 10⁻⁴ 16～17 ion / cm 2 .

[0017] According to a preferred embodiment of the present invention, Fe is used at high temperature. 2+ When the surface of the methylamine lead bromide crystal sample was irradiated with ions at a temperature of 600-650℃, Fe... 2+ The ion-selective dose is 1×10 17 ion / cm 2 .

[0018] According to a preferred embodiment of the present invention, Fe 2+ The ion implantation amount was 1e13 to 1e14.

[0019] A single-phase multiferroelectric coupling material was prepared using the method described above.

[0020] The application of the single-phase multi-ferromagnetic electric coupling material is used for preparing a single-phase multi-ferromagnetic electric coupling device.

[0021] A method for preparing a single-phase multi-ferromagnetic electric coupling device based on ion implantation, which comprises, from bottom to top, a conductive ITO, an active layer, a shielding layer, and an electrode layer.

[0022] The method comprises the following steps:

[0023] 1) Dissolving the prepared single-phase multi-ferromagnetic electric coupling material in N, N-dimethylformamide (DMF) to obtain a mixture, coating the mixture on the surface of the conductive ITO by spin coating, and annealing to obtain the conductive ITO provided with the active layer;

[0024] 2) Spin coating polymethyl methacrylate (PMMA) on the surface of the active layer of the conductive ITO provided with the active layer to obtain the shielding layer, and evaporating the electrode on the shielding layer to obtain the single-phase multi-ferromagnetic electric coupling device.

[0025] According to the application, preferably, in step 1), the concentration of the single-phase multi-ferromagnetic electric coupling material in the mixture is 200-400 mg / ml.

[0026] Further preferably, in step 1), the concentration of the single-phase multi-ferromagnetic electric coupling material in the mixture is 300 mg / ml.

[0027] According to the application, preferably, in step 1), the spin coating rate is 1000-2000 rpm, and further preferably, in step 1), the spin coating rate is 1500 rpm.

[0028] According to the application, preferably, in step 1), the annealing is annealing at 85-95 ℃ for 20 minutes.

[0029] According to the application, preferably, in step 1), the thickness of the active layer is 150-200 nm.

[0030] According to the application, preferably, in step 2), the thickness of the shielding layer is 50-150 nm.

[0031] According to the application, preferably, in step 2), the electrode layer is a silver electrode, the electrode layer is a first electrode, and the conductive ITO is a second electrode.

[0032] Advantages of the application

[0033] 1. The application uses Fe 2+The surface of a methylammonium lead bromide crystal sample is irradiated by ions to obtain a single-phase multi-ferromagnetic and electrically coupled material, which has ferromagnetism and a large dielectric constant, and has a strong magnetoelectric coupling effect in a wide temperature range, especially at room temperature, and also has a strong magnetoelectric coupling effect, and has great application potential in the fields of spintronic devices, multi-state information storage and the like.

[0034] 2. The material is widely sourced, can be processed by solution, has a simple process, and can be prepared in a large area. BRIEF DESCRIPTION OF DRAWINGS

[0035] The above and other objects, features and advantages of the present application will become more apparent from the following description of embodiments of the present application with reference to the accompanying drawings, in which:

[0036] Figure 1a No Fe for Comparative Example 1 2+ Ion implantation, i.e., optical photograph of intrinsic CH3NH3PbBr3 perovskite;

[0037] Figure 1b Optical photograph of CH3NH3PbBr3 perovskite obtained from Example 1;

[0038] Figure 1c Optical photograph of CH3NH3PbBr3 perovskite obtained from Example 2;

[0039] Figure 1d Optical photograph of CH3NH3PbBr3 perovskite obtained from Example 3;

[0040] Figure 2 Magnetic hysteresis loop of CH3NH3PbBr3 perovskite obtained from Example 1 at different temperatures;

[0041] Figure 3 Magnetic hysteresis loop of CH3NH3PbBr3 perovskite obtained from Example 3 at different temperatures;

[0042] Figure 4 Single-phase multi-ferromagnetic and electrically coupled device prepared from Example 4, magnetic field regulation curve of dielectric;

[0043] Figure 5 Single-phase multi-ferromagnetic and electrically coupled device prepared from Example 5, magnetic field regulation curve of dielectric;

[0044] Figure 6 Single-phase multi-ferromagnetic and electrically coupled device prepared from Example 4, electric field regulation curve of magnetization.

[0045] Figure 7 Single-phase multi-ferromagnetic and electrically coupled device prepared from Example 5, electric field regulation curve of magnetization. DETAILED DESCRIPTION

[0046] In order to make some details of the present application clearer, the present application will be further described in the following specific examples, but not limited thereto.

[0047] CH3NH3PbBr3 and DMF described in the examples are commercially available products.

[0048] CH3NH3PbBr3 described in the present application can also be synthesized according to the method described in Chinese invention patent CN108034989A.

[0049] Figure 1a 、 Figure 1b 、 Figure 1c and Figure 1d respectively show the intrinsic CH3NH3PbBr3 sample, and Fe 2+ Optical photo of CH3NH3PbBr3 sample ion implanted.

[0050] Example 1

[0051] The method for preparing single-phase multi-ferromagnetic electric coupling material based on ion implantation is as follows:

[0052] The surface of the methyammonium lead bromide crystal sample is irradiated with Fe 2+ ions at room temperature, and the irradiation dose of Fe 2+ ions is controlled to be 1×10 16 ion / cm 2 , the acceleration voltage is 300-400KeV, the energy of Fe 2+ ions is 3MeV, and the average atomic displacement energy is 30eV, so that ion implantation is realized on the methyammonium lead bromide crystal, and after the implantation is completed, the Fe 2+ ion implantation amount is 1e13.

[0053] Example 2

[0054] The method for preparing single-phase multi-ferromagnetic electric coupling material based on ion implantation described in Example 1 is different in that:

[0055] The Fe 2+ ion implantation amount is 5e13, and the others are performed according to Example 1.

[0056] Example 3

[0057] The method for preparing single-phase multi-ferromagnetic electric coupling material based on ion implantation described in Example 1 is different in that:

[0058] The Fe 2+ ion implantation amount is 1e14, and the others are performed according to Example 1.

[0059] Comparative Example 1

[0060] The method for preparing single-phase multiferromagnetic-electric coupling materials based on ion implantation as described in Example 1 differs in that:

[0061] No Fe 2+ Ion implantation, i.e., intrinsic CH3NH3PbBr3 perovskite.

[0062] Example 4

[0063] A method for fabricating a single-phase multiferromagnetic-electric coupling device based on ion implantation, wherein the single-phase multiferromagnetic-electric coupling device comprises, from bottom to top, conductive ITO, an active layer, a shielding layer, and an electrode layer; the method includes the following steps:

[0064] 1) The single-phase multiferromagnetic coupling material prepared in Example 1 was dissolved in N,N-dimethylformamide (DMF) to obtain a mixture. The mixture was stirred vigorously, and the sample was quickly and completely dissolved in DMF. The concentration of the single-phase multiferromagnetic coupling material in the mixture was 300 mg / ml. The dissolved CH3NH3PbBr3 perovskite solution was spin-coated onto ITO at a rate of 1000 rpm, and then annealed at 90°C for 20 minutes to obtain conductive ITO with an active layer.

[0065] 2) Spin-coat polymethyl methacrylate (PMMA) onto the surface of the active layer of conductive ITO to obtain a shielding layer. Evaporate electrodes onto the shielding layer to obtain a single-phase multiferromagnetic coupling device. The electrode layer is a silver electrode, which is the first electrode, and the conductive ITO is the second electrode.

[0066] Example 5

[0067] The method described in the same way as in Example 4 differs in that:

[0068] In step 1), the single-phase multiferromagnetic coupling material prepared in Example 3 is dissolved in N,N-dimethylformamide (DMF) to obtain a mixture, and the rest is carried out as in Example 1.

[0069] Experimental example:

[0070] 1. Optical photographs of the materials in Examples 1-3 and Comparative Example 1 are shown below. Figures 1a-1d As shown, Figure 1a , Figure 1b , Figure 1c and Figure 1d The intrinsic CH3NH3PbBr3 sample and samples with different doses of Fe are shown. 2+ The color of the CH3NH3PbBr3 sample after ion implantation was determined by... Figures 1a-1d It can be seen that with Fe 2+ As the amount of ion implanted increases, the sample color gradually deepens, indicating that Fe 2+Ion injection is successful.

[0071] 2、 Figure 2 Hysteresis loops of CH3NH3PbBr3 perovskite obtained from Example 1 at different temperatures; Figure 3 Hysteresis loops of CH3NH3PbBr3 perovskite obtained from Example 3 at different temperatures; and Figure 2 、 Figure 3 It can be seen that the single-phase multi-ferromagnetic and electrically coupled material prepared by ion injection has strong magnetoelectric coupling effect at 80K-300K temperature, and overcomes the problem that the existing magnetoelectric coupling effect can only be exhibited at 100K-200K lower temperature and has no magnetoelectric coupling effect at room temperature.

[0072] 3, the single-phase multi-ferromagnetic and electrically coupled device of Example 4 is placed in a magnetic field, and the magnetic field regulation curve of dielectric is as shown in Figure 4 The single-phase multi-ferromagnetic and electrically coupled device of Example 5 is placed in a magnetic field, and the magnetic field regulation curve of dielectric is as shown in Figure 5 Figure 4 、 Figure 5 It can be seen that the single-phase multi-ferromagnetic and electrically coupled device of the application can be magnetically regulated, and the more iron ions are injected, the better the performance is.

[0073] 4, the single-phase multi-ferromagnetic and electrically coupled device of Example 4 is externally connected to electricity, and an electric field is applied, and the electric field regulation curve of magnetization is as shown in Figure 6 The single-phase multi-ferromagnetic and electrically coupled device of Example 5 is externally connected to electricity, and an electric field is applied, and the electric field regulation curve of magnetization is as shown in Figure 7 Figure 6 、 Figure 7 It can be seen that the single-phase multi-ferromagnetic and electrically coupled device of the application can be magnetically regulated, and the more iron ions are injected, the better the performance is.​​

Claims

1. A method for preparing single-phase multiferromagnetic-electric coupling materials based on ion implantation, the method comprising: ion implantation of Fe... 2+ Ion implantation into methylamine lead bromide crystal CH3NH3PbBr3 yielded a single-phase multiferromagnetic coupling material; Fe 2+ The specific method for ion implantation of methylamine lead bromide crystal CH3NH3PbBr3 is as follows: Fe is used at room temperature or high temperature 2+ Ion irradiation of the surface of methylamine lead bromide crystal sample, with controlled Fe irradiation 2+ The ion-selective dose is 1-5×10 16～17 ion / cm 2 The accelerating voltage is 300-400 keV, Fe 2+ Ion implantation is achieved with ion energies of 1-4 MeV and average atomic displacement energies of 25-35 eV, resulting in Fe... 2+ The ion implantation amount was 1e13 to 1e14.

2. The method according to claim 1, characterized in that, Fe at room temperature 2+ When the surface of a methylamine lead bromide crystal sample is irradiated with ions, Fe 2+ The ion-selective dose is 1-4 × 10⁻⁴ 16 ～17 ion / cm 2 .

3. The method according to claim 1, characterized in that, Fe at high temperature 2+ When the surface of the methylamine lead bromide crystal sample was irradiated with ions at a temperature of 600-650℃, Fe... 2+ The ion-selective dose is 1×10 17 ion / cm 2 .

4. A single-phase multiferromagnetic coupling material, prepared by the method described in any one of claims 1-3.

5. The application of the single-phase multiferromagnetic coupling material obtained by the method according to any one of claims 1-3, for the preparation of single-phase multiferromagnetic coupling devices.

6. A method for fabricating a single-phase multiferromagnetic-electric coupling device based on ion implantation, wherein the single-phase multiferromagnetic-electric coupling device comprises, from bottom to top, conductive ITO, an active layer, a shielding layer, and an electrode layer; The steps include the following: 1) Dissolve the single-phase multiferromagnetic coupling material prepared by the method according to any one of claims 1-3 in N,N-dimethylformamide (DMF) to obtain a mixture, coat the mixture onto the surface of conductive ITO by spin coating, and anneal to obtain conductive ITO with an active layer. 2) Spin-coat polymethyl methacrylate (PMMA) onto the surface of the active layer of conductive ITO to obtain a shielding layer. Then, deposit electrodes on the shielding layer to obtain a single-phase multiferroelectric coupling device.

7. The method according to claim 6, characterized in that, In step 1), the concentration of the single-phase multiferromagnetic coupling material in the mixture is 200-400 mg / ml, the spin coating rate is 1000-2000 rpm, the annealing is performed at 85-95℃ for 20 minutes, and the thickness of the active layer is 150-200 nm.

8. The method according to claim 6, characterized in that, In step 2), the thickness of the shielding layer is 50-150nm, the electrode layer is a silver electrode, the electrode layer is the first electrode, and the conductive ITO is the second electrode.

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