Nitrogen-doped cuprous oxide with room-temperature ferromagnetism and its preparation method

Abstract

A preparation method of nitrogen-doped cuprous oxide with room-temperature ferromagnetism is disclosed. In the method, a predetermined ratio of copper sulfate and ethylenediaminetetraacetic acid are dissolved in deionized water, and a first solution is obtained after sufficient stirring; a predetermined mass of urea is added to the first solution, and a second solution is obtained after sufficient stirring and dissolution; the second solution is treated with a strong alkaline solution and a glucose solution to obtain a primary solution; the primary solution is ultrasonicated, centrifuged, and dried to obtain a final product of nitrogen-doped cuprous oxide magnetic powder with room-temperature ferromagnetism.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic materials with room-temperature ferromagnetism, and particularly relates to a nitrogen-doped cuprous oxide with room-temperature ferromagnetism and a preparation method thereof. Background Art

[0002] Modern information technology has successfully utilized the charge and spin properties of electrons. Among them, devices for storing information, such as hard disks and optical discs, utilize the spin of electrons in magnetic materials, while information processing devices, such as central processing units, etc., rely on the charge movement of electrons in semiconductor materials to complete tasks. Diluted magnetic semiconductors can utilize both the charge and spin of electrons simultaneously. The electronic devices made therefrom have characteristics such as large capacity, multiple functions, low energy consumption, and non-volatility, and are the main materials for next-generation microelectronic devices.

[0003] Currently, diluted magnetic semiconductors can be divided into II-VI group diluted magnetic semiconductors, III-V group diluted magnetic semiconductors, IV-VI group diluted magnetic semiconductors, oxide diluted magnetic semiconductors, etc. However, among them, the II-VI group diluted magnetic semiconductors have a low carrier concentration, and the magnetic properties of the materials are severely dependent on the preparation conditions; the III-V group diluted magnetic semiconductors have a relatively low Curie temperature and cannot exhibit ferromagnetism at room temperature; there is less research on IV-VI group diluted magnetic semiconductors, and the origin of ferromagnetism is unclear; while oxide diluted magnetic semiconductors have the advantages of simple preparation, rich raw materials, and a Curie temperature higher than room temperature, and are a type of diluted magnetic semiconductor material with broad application prospects.

[0004] Cuprous oxide is a promising p-type semiconductor material with a band gap of 2.1 eV. In the past few years, the existing literature has reported that doping transition metal elements such as Fe, Ni, Co, Mn, etc. in cuprous oxide can change cuprous oxide from diamagnetic to paramagnetic. At the same time, there are also literatures indicating that the doping of non-metal elements, such as N, C, etc., can regulate the properties of cuprous oxide such as band gap, carrier type, and concentration, but there are few reports on magnetic-related research.

[0005] Doping non-metal elements in cuprous oxide has the advantages of lower raw material costs and more diverse preparation methods. Moreover, since non-metal elements replace different positions in the lattice of cuprous oxide from transition metal elements, some unique and novel phenomena may occur. Therefore, developing a template method with low cost and good controllability to achieve the doping of non-metal element nitrogen in the cuprous oxide lattice is of great significance for improving the magnetic properties of cuprous oxide-based diluted magnetic semiconductors and expanding their applications.

[0006] The above information disclosed in the background art section is only used to enhance the understanding of the background of the present invention, and thus may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0007] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a nitrogen-doped cuprous oxide with room-temperature ferromagnetism and a preparation method thereof. The cuprous oxide matrix material is prepared by a redox method, and nitrogen-doped cuprous oxide nanopowder with low cost and room-temperature ferromagnetism is obtained by a chemical coprecipitation method, and it has excellent magnetic properties.

[0008] To achieve the above purpose, the present invention provides the following technical solutions:

[0009] The preparation method of a nitrogen-doped cuprous oxide with room-temperature ferromagnetism according to the present invention includes:

[0010] A predetermined ratio of copper sulfate and ethylenediaminetetraacetic acid are dissolved in deionized water, and after sufficient stirring, a first solution is obtained;

[0011] A predetermined mass of urea is added to the first solution, and after sufficient stirring and dissolution, a second solution is obtained;

[0012] The second solution is treated with a strong alkaline solution and a glucose solution to obtain a primary solution;

[0013] The primary solution is ultrasonicated, centrifuged, and dried to obtain the final product of nitrogen-doped cuprous oxide magnetic powder.

[0014] In the method described above, the predetermined ratio is 2∶1, 2∶0, 4∶1, and 3∶1.

[0015] In the method described above, copper sulfate and ethylenediaminetetraacetic acid are dissolved in deionized water, and after sufficient stirring at room temperature for 1-4 h, a first solution is obtained.

[0016] In the method described above, a predetermined mass of urea is added to the first solution so that the atomic ratio of N:Cu is 1%-5%.

[0017] In the method described above, the second solution is placed in a water bath at 50°C - 60°C. After the temperature is stable, first add 10 ml of a strong alkaline solution with a molar concentration of 3 M of hydroxide ions, and continuously stir for 5-10 min. Then add 20 ml of a glucose solution with a molar concentration of 0.11 M, and react at a constant temperature of 50°C - 60°C for 1-2 h to obtain a primary solution mixed with reddish-brown precipitate.

[0018] In the method described above, after the primary solution is ultrasonicated and centrifuged and washed several times, it is placed in a vacuum drying oven with a temperature set at 50°C - 60°C and vacuum dried for 12 h to obtain the final product of nitrogen-doped cuprous oxide powder with room-temperature ferromagnetism.

[0019] A nitrogen-doped cuprous oxide powder is made by the method described above.

[0020] In the nitrogen-doped cuprous oxide powder, the magnetization intensity of the nitrogen-doped cuprous oxide powder at a magnetic field strength of -5 to 5 kOe is 0.5 - 0.28×10- 2 emu / g -1 .

[0021] Beneficial effects

[0022] The preparation method of nitrogen-doped cuprous oxide with room-temperature ferromagnetism uses a redox method to prepare a cuprous oxide matrix material, and obtains nitrogen-doped cuprous oxide nanometer powder with low cost and room-temperature ferromagnetism through a chemical coprecipitation method, significantly improving the magnetic properties of cuprous oxide-based dilute magnetic semiconductors.

[0023] The above description is only an overview of the technical solution of the present invention. In order to make the technical means of the present invention clearer and to the extent that those skilled in the art can implement it according to the content of the specification, and in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the following takes the specific implementation manners of the present invention as examples for illustration. Brief description of the drawings

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings.

[0025] By reading the detailed description of the preferred specific implementation manners below, various other advantages and benefits of the present invention will become clear to those of ordinary skill in the art. The drawings in the specification are only for the purpose of showing the preferred implementation manners, and are not considered to be a limitation of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts. Moreover, throughout the drawings, the same reference numerals are used to represent the same components.

[0026] In the drawings:

[0027] Figure 1 is the morphology diagram of the undoped cuprous oxide powder obtained in Comparative Example 1;

[0028] Figure 2 is the morphology diagram of the nitrogen-doped cuprous oxide powder prepared by the preparation method of nitrogen-doped cuprous oxide with room-temperature ferromagnetism according to the present invention;

[0029] Figure 3 is the hysteresis loop diagram of the doped and nitrogen-doped cuprous oxide powders according to Comparative Example 1 and Example 1.

[0030] The present invention will be further explained below in conjunction with the accompanying drawings and embodiments. Specific Embodiments

[0031] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0032] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0034] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0035] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0036] In the present invention, unless otherwise clearly specified or limited, the terms "installed", "connected", "connected", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] In the present invention, unless otherwise clearly specified or limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over" and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely means that the horizontal height of the first feature is lower than that of the second feature.

[0038] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings, and each accompanying drawing does not constitute a limitation on the embodiments of the present invention.

[0039] In one embodiment, as Figures 1 to 3 shown, the present disclosure provides a preparation method of nitrogen-doped cuprous oxide with room-temperature ferromagnetism, comprising the following steps:

[0040] A predetermined ratio of copper sulfate and ethylenediaminetetraacetic acid are dissolved in deionized water, and a first solution is obtained after sufficient stirring.

[0041] A predetermined mass of urea is added to the first solution, and a second solution is obtained after sufficient stirring and dissolution.

[0042] The second solution is treated with a strong alkaline solution and a glucose solution to obtain a primary solution.

[0043] The primary solution is ultrasonicated, centrifuged, and dried to obtain the final product of nitrogen-doped cuprous oxide magnetic powder.

[0044] In the described method, the predetermined ratio is 2:1, 2:0, 4:1, and 3:1.

[0045] In the described method, copper sulfate and ethylenediaminetetraacetic acid are dissolved in deionized water and stirred at room temperature for 1-4 h to obtain a first solution.

[0046] In the method, a predetermined mass of urea is added to the first solution so that the atomic ratio of N:Cu is 1%-5%.

[0047] In the method, the second solution is placed in a water bath at 50°C-60°C, and after the temperature stabilizes, 10 ml of a strong alkaline solution with a molar concentration of 3 M hydroxide is added, and stirring is continued for 5-10 minutes, and then 20 ml of a glucose solution with a molar concentration of 0.11 M is added, and the reaction is carried out at a constant temperature of 50°C-60°C for 1-2 hours to obtain a primary solution mixed with a red precipitate.

[0048] In the method, the primary solution is ultrasonically centrifugally cleaned several times and then placed in a vacuum drying oven set at a temperature of 50° C.-60° C. for vacuum drying for 12 hours to obtain a final product of nitrogen-doped cuprous oxide powder having room temperature ferromagnetism.

[0049] In one embodiment, a method for preparing nitrogen-doped cuprous oxide having room temperature ferromagnetism comprises the following steps:

[0050] A certain amount of copper sulfate and ethylenediaminetetraacetic acid (EDTA) are dissolved in deionized water and stirred sufficiently to obtain a first solution.

[0051] A certain amount of urea is added to the first solution, and the solution is stirred to be fully dissolved to obtain a second solution.

[0052] The secondary solution is treated with an alkaline solution and a glucose solution to obtain a primary solution.

[0053] The primary solution is ultrasonicated, centrifuged and dried to obtain the final product, nitrogen-doped cuprous oxide magnetic powder having room temperature ferromagnetism.

[0054] Comparative Example 1: Undoped cuprous oxide powder

[0055] (1) Dissolve 4 mmol of copper sulfate (CuSO4) and 2 mmol of ethylenediaminetetraacetic acid (EDTA) in 80 ml of deionized water and stir thoroughly at room temperature for 1 h to obtain a blue clear solution;

[0056] (2) This solution is not doped;

[0057] (3) The obtained solution was placed in a water bath at 55°C. After the temperature stabilized, 10 ml of a 3M sodium hydroxide (NaOH) solution was added and stirred for 5 to 10 min. Then, 20 ml of a 0.11M glucose solution was added and the mixture was reacted at 55°C for 1 h to obtain a solution mixed with a red precipitate.

[0058] (4) After the reddish brown precipitate was cleaned several times by ultrasonic centrifugation, it was placed in a vacuum drying oven set at 55°C and vacuum dried for 12 hours to obtain the final product, cuprous oxide powder.Figure 1 , the morphology of undoped cuprous oxide powder.

[0059] Example 1:

[0060] Dissolve 4 mmol of copper sulfate (CuSO4) and 2 mmol of ethylenediaminetetraacetic acid (EDTA) in 80 ml of deionized water, and stir well at room temperature for 1 h to obtain a blue clear solution A; add urea powder with an atomic ratio of N:Cu = 1% to solution A, and stir at room temperature for 1 h to obtain solution B; place solution B in a water bath at 55 °C. After the temperature stabilizes, first add 10 ml of sodium hydroxide (NaOH) solution with a molar concentration of 3 M, and continuously stir for 5 - 10 min. Then add 20 ml of glucose solution with a molar concentration of 0.11 M, and react at a constant temperature of 55 °C for 1 h to obtain a solution mixed with reddish-brown precipitate; after ultrasonic centrifugal cleaning the reddish-brown precipitate several times, place it in a vacuum drying oven with a set temperature of 55 °C and vacuum dry for 12 h to obtain nitrogen-doped cuprous oxide powder with room-temperature ferromagnetism as the final product.

[0061] Example 2:

[0062] Dissolve 4 mmol of copper sulfate (CuSO4) and 2 mmol of ethylenediaminetetraacetic acid (EDTA) in 80 ml of deionized water, and stir well at room temperature for 1 h to obtain a blue clear solution A; add urea powder with an atomic ratio of N:Cu = 2.8% to solution A, and stir at room temperature for 1 h to obtain solution B; place solution B in a water bath at 55 °C. After the temperature stabilizes, first add 10 ml of sodium hydroxide (NaOH) solution with a molar concentration of 3 M, and continuously stir for 5 - 10 min. Then add 20 ml of glucose solution with a molar concentration of 0.11 M, and react at a constant temperature of 55 °C for 1 h to obtain a solution mixed with reddish-brown precipitate; after ultrasonic centrifugal cleaning the reddish-brown precipitate several times, place it in a vacuum drying oven with a set temperature of 55 °C and vacuum dry for 12 h to obtain nitrogen-doped cuprous oxide powder with room-temperature ferromagnetism as the final product. See Figure 2 the morphology of the nitrogen-doped cuprous oxide powder.

[0063] Example 3:

[0064] Dissolve 4 mmol of copper sulfate (CuSO4) and 2 mmol of ethylenediaminetetraacetic acid (EDTA) in 80 ml of deionized water, and stir well at room temperature for 1 h to obtain a blue clear solution A; add urea powder with an atomic ratio of N:Cu = 5% to solution A, and stir at room temperature for 1 h to obtain solution B; place solution B in a water bath at 55 °C. After the temperature stabilizes, first add 10 ml of sodium hydroxide (NaOH) solution with a molar concentration of 3 M, and continuously stir for 5 - 10 min. Then add 20 ml of glucose solution with a molar concentration of 0.11 M, and react at a constant temperature of 55 °C for 1 h to obtain a solution mixed with reddish-brown precipitate; after ultrasonic centrifugation and washing the reddish-brown precipitate several times, place it in a vacuum drying oven with a set temperature of 55 °C and vacuum dry for 12 h to obtain nitrogen-doped cuprous oxide powder with room-temperature ferromagnetism as the final product.

[0065] Example 4:

[0066] Dissolve 4 mmol of copper sulfate (CuSO4) and 1 mmol of ethylenediaminetetraacetic acid (EDTA) in 80 ml of deionized water, and stir well at room temperature for 1 h to obtain a blue clear solution A; add urea powder with an atomic ratio of N:Cu = 2.8% to solution A, and stir at room temperature for 1 h to obtain solution B; place solution B in a water bath at 60 °C. After the temperature stabilizes, first add 10 ml of potassium hydroxide (KOH) solution with a molar concentration of 3 M, and continuously stir for 5 - 10 min. Then add 20 ml of glucose solution with a molar concentration of 0.11 M, and react at a constant temperature of 60 °C for 2 h to obtain a solution mixed with reddish-brown precipitate; after ultrasonic centrifugation and washing the reddish-brown precipitate several times, place it in a vacuum drying oven with a set temperature of 60 °C and vacuum dry for 12 h to obtain nitrogen-doped cuprous oxide powder with room-temperature ferromagnetism as the final product.

[0067] In the cases shown in Examples 1 to 4, due to the pH value during the preparation process, the ratio of N to Cu in the final material in Example 2 can achieve the best saturation magnetization intensity effect. A nitrogen-doped cuprous oxide powder with room-temperature ferromagnetism is prepared by the described method.

[0068] The magnetization intensity of the described nitrogen-doped cuprous oxide powder with room-temperature ferromagnetism is 0.5 - 0.2810 -2 emu.g -1 at a magnetic field strength of -5 to 5 kiloOersteds. See Figure 3 the hysteresis loops of undoped and nitrogen-doped cuprous oxide powders.

[0069] Although the embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above specific embodiments and application fields. The above specific embodiments are merely illustrative and guiding, rather than restrictive. Those of ordinary skill in the art can also make many forms under the inspiration of this specification and without departing from the scope protected by the claims of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A method for preparing nitrogen-doped cuprous oxide having room temperature ferromagnetism, characterized in that: It includes the following steps: Dissolving copper sulfate and ethylenediaminetetraacetic acid in a predetermined ratio in deionized water, and stirring thoroughly to obtain a first solution; Adding a predetermined mass of urea with an atomic ratio of N:Cu=2.8% to the first solution, stirring and fully dissolving to obtain a second solution; treating the second solution with an alkaline solution and a glucose solution to obtain a primary solution; After the primary solution was ultrasonically centrifuged and cleaned several times, it was placed in a vacuum drying oven set at 50°C-60°C and vacuum dried for 12 hours to obtain the final product of nitrogen-doped cuprous oxide powder with room temperature ferromagnetism, and its magnetization intensity at a magnetic field strength of -5 to 5 kilo-oersted was 0.5-0.28×10 -2 emu.g -1 .

2. The method according to claim 1, characterized in that The predetermined ratios are 2:1, 4:1 and 3:

1.

3. The method according to claim 1, characterized in that Copper sulfate and ethylenediaminetetraacetic acid are dissolved in deionized water and stirred at room temperature for 1-4 hours to obtain a first solution.

4. A nitrogen-doped cuprous oxide powder having room temperature ferromagnetism, characterized in that: It is prepared by the method according to any one of claims 1 to 3.

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