WO2020111385A1 - Rare earth metal plating solution, rare earth metal composite structure, and method for plating rare earth metal - Google Patents

Abstract

A method for plating rare earth metal is provided. The method for plating rare earth metal may comprise the steps of: preparing a base metal comprising a calcium (Ca) compound and a rare earth metal compound; preparing a plating source including a calcium reactant, a first metal precursor comprising a first metal, and a second metal precursor comprising a second metal; and providing the plating source to the base metal so that while the calcium included in the calcium compound reacts with the calcium reactant, an alloy of the first metal and the second metal is plated on the surface of the rare earth metal compound.

Description

Rare earth metal plating solution, rare earth composite structure, and plating method of rare earth metal

The present invention relates to a rare earth metal plating solution, a rare earth composite structure, and a method for plating a rare earth metal, and more particularly, to a rare earth metal plating solution for plating a rare earth metal, a rare earth composite structure, and a method for plating a rare earth metal.

Methods for improving mechanical properties such as corrosion resistance, durability, and acid resistance by adding metal B to metal A are well known. For example, in the technique of synthesizing a composite structure, a technique of simply mixing and processing each powder or each precursor material, coating or depositing B on metal A, or coating a metal B film or core-shell (core- shell) has been reported. In particular, in order to obtain a homogeneous structure, it is most common to form a film through electroless plating or electrolytic plating. Unlike electrolytic plating, in which electrical energy must be supplied, electroless plating is a plating method in which metal ions in a plating solution are catalytically reduced by a reducing agent to precipitate metal on the surface of the mother phase.

In this electroless plating method, a platinum (Pd)-tin (Sn) catalyst must be applied to the substrate surface. In this process, hydrochloric acid (HCl), which is a very strong acid, is used as a Pd-Sn precursor solution. These can not only cause damage to the metal matrix, but also have a disadvantage in that a filtration and washing process of the metal matrix is required several times from the catalytic treatment that has been roughly performed in two steps. In particular, when the rare earth metal materials including scandium, yttrium, and lanthanide elements (La to Lu) are plated by an electroless plating method, there is a great risk of damage to the rare earth metal as a base material. Accordingly, studies have been actively conducted on a method of forming a homogeneous plating film without damaging the rare earth metal.

One technical problem to be solved by the present invention is to provide a rare-earth metal plating solution, a rare-earth composite structure, and a rare-earth metal plating method with a simplified process.

Another technical problem to be solved by the present invention is to provide a rare earth metal plating solution with improved acid resistance, corrosion resistance, and durability, a rare earth composite structure, and a method for plating a rare earth metal.

Another technical problem to be solved by the present invention is to provide a rare earth metal plating solution using a by-product of a reducing agent, a rare earth composite structure, and a method for plating a rare earth metal.

The technical problem to be solved by the present invention is not limited to the above.

In order to solve the above technical problems, the present invention provides a method for plating rare earth metals.

According to one embodiment, the method of plating the rare earth metal comprises: preparing a base metal including a calcium (Ca) compound, and a rare earth metal compound, a calcium reactant, a first metal precursor including a first metal, and Preparing a plating source including a second metal precursor containing a second metal, and providing the plating source to the base metal, thereby reacting the calcium contained in the calcium compound with the calcium reactant, And plating an alloy of the first metal and the second metal on the surface of the rare earth metal compound.

According to one embodiment, when the base metal is provided with the plating source, the calcium compound is dissociated into calcium ions and electrons, the first metal of the first metal precursor, and the second metal of the second metal precursor It may include that formed of an alloy of the first and second metals by receiving the electrons.

According to one embodiment, the calcium ion may include reacting with the calcium reactant to form a functional material.

According to an embodiment, the calcium reactant may include fluorine (F), and the functional material may include a reaction between a fluorine anion and a calcium cation.

According to one embodiment, the calcium reactant may include any of NH ₄ F or HF.

According to one embodiment, the preparing of the base metal includes preparing a base precursor comprising a rare earth element and a metal element, and reducing the base precursor using a reducing agent containing calcium. can do.

According to one embodiment, the rare earth element, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, or at least any one of Lu It can contain.

According to an embodiment, the calcium compound may include calcium oxide (CaO).

According to one embodiment, the preparing of the plating source comprises mixing ultrapure water and the calcium reactant to prepare a mixed solution, and providing the first metal precursor and the second metal precursor to the mixed solution. However, the ratio of the first metal precursor and the second metal precursor provided to the mixed solution may include different things.

According to an embodiment, the sum of the number of moles of the first metal included in the first metal precursor and the number of moles of the second metal included in the second metal precursor may include more than 1 mmol and less than 75 mmol.

According to one embodiment, the plating step, by reacting the plating source to the base metal, on the rare earth metal compound, the functional material, the alloy of the first and second metal, the calcium and the calcium reactant reacted , And an alloy oxide of the first and second metals, a pre-plating layer forming step, and reducing the pre-plating layer, so that the functional material and the first and second metal alloys are formed on the rare-earth metal compound. It may include the step of forming a plating layer comprising a.

In order to solve the above technical problems, the present invention provides a rare earth metal plating solution.

According to one embodiment, as a plating solution of a base metal containing a calcium (Ca) compound, and a rare earth compound, the plating solution is a calcium reactant containing fluorine (F), the first having a lower ionization tendency than the calcium The metal may include a first metal precursor including a metal, and a second metal precursor including a second metal having a lower ionization tendency than calcium.

In order to solve the above technical problems, the present invention provides a rare earth composite structure.

According to one embodiment, the rare earth composite structure is a rare earth metal compound, and

An alloy of a first metal and a second metal, and a functional material comprising fluorine (F), including a plating layer surrounding the rare earth metal compound, wherein the content of the alloy in the plating layer is It may contain more than the content.

According to one embodiment, the alloy, and the functional material may include those produced at the same time.

Plating method of the rare earth metal according to an embodiment of the present invention, the step of preparing a base metal comprising a calcium (Ca) compound, and a rare earth metal compound, a calcium reactant, a first metal precursor comprising a first metal, agent Preparing a plating source including a second metal precursor containing 2 metals, and providing the plating source to the base metal, thereby reacting the calcium contained in the calcium compound with the calcium reactant, and And plating an alloy of the first metal and the second metal on the surface of the rare earth metal compound.

That is, the method of plating the rare earth metal according to the embodiment may be plated using a by-product without removing the by-product of a reducing agent containing Ca. Accordingly, a method of plating rare earth metals may be provided as a process of removing Ca by-products and a simplified process without catalytic treatment.

1 is a flowchart illustrating a method of plating a rare earth metal according to an embodiment of the present invention.

Figure 2 is a flow chart specifically explaining the base metal preparation step of the method of plating the rare earth metal according to an embodiment of the present invention.

3 is a view showing a base metal used in the method of plating a rare earth metal according to an embodiment of the present invention.

4 is a flowchart specifically explaining a step of preparing a plating source among plating methods of rare earth metals according to an exemplary embodiment of the present invention.

5 is a flowchart specifically explaining a plating step of a method of plating a rare earth metal according to an embodiment of the present invention.

6 is a view showing a plating process of a rare earth metal according to an embodiment of the present invention.

7 is a view showing a rare earth composite structure according to an embodiment of the present invention.

8 is a photograph of a base metal according to an embodiment of the present invention.

9 is a photograph of a rare earth composite structure according to Example 1 of the present invention.

10 is a photograph of a rare earth composite structure according to Example 2 of the present invention.

11 to 15 are photographs of rare earth composite structures according to Examples 3 to 7 of the present invention.

16 is a photograph of a rare earth composite structure according to Example 8 of the present invention.

17 and 18 are diagrams showing components of a rare earth composite structure according to Example 7 of the present invention.

19 is a graph showing the configuration of a rare earth composite structure according to embodiments of the present invention.

20 is a graph showing the configuration of a base metal and a rare earth composite structure according to Example 6 of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the technical spirit of the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed contents are thorough and complete and that the spirit of the present invention is sufficiently conveyed to those skilled in the art.

In the present specification, when a component is referred to as being on another component, it means that it may be formed directly on another component, or a third component may be interposed between them. In addition, in the drawings, the thickness of the films and regions are exaggerated for effective description of the technical content.

In addition, in various embodiments of the present specification, terms such as first, second, and third are used to describe various components, but these components should not be limited by these terms. These terms are only used to distinguish one component from another component. Therefore, what is referred to as the first component in one embodiment may be referred to as the second component in another embodiment. Each embodiment described and illustrated herein also includes its complementary embodiment. In addition, in this specification,'and/or' is used to mean including at least one of the components listed before and after.

In the specification, a singular expression includes a plural expression unless the context clearly indicates otherwise. Also, terms such as “include” or “have” are intended to indicate the presence of features, numbers, steps, elements, or combinations thereof described in the specification, and one or more other features, numbers, steps, or configurations. It should not be understood as excluding the possibility of the presence or addition of elements or combinations thereof. In addition, in the present specification, “connecting” is used in a sense to include both indirectly connecting a plurality of components, and directly connecting.

In addition, in the following description of the present invention, when it is determined that detailed descriptions of related known functions or configurations may unnecessarily obscure the subject matter of the present invention, detailed descriptions thereof will be omitted.

1 is a flowchart illustrating a method of plating a rare earth metal according to an embodiment of the present invention, and FIG. 2 is a flowchart illustrating a step of preparing a base metal among plating methods of a rare earth metal according to an embodiment of the present invention. 3 is a view showing a base metal used in the method of plating the rare earth metal according to an embodiment of the present invention, Figure 4 is a flow chart specifically explaining the plating source preparation step of the plating method of the rare earth metal according to an embodiment of the present invention to be.

1 to 3, a base metal 100 including a calcium (Ca) compound 120 and a rare earth metal compound 110 may be prepared (S110 ). According to an embodiment, the base metal 100 preparation step (S110) includes preparing a base precursor comprising a rare earth element and a metal element (S112), and the base precursor 100 containing calcium. It may include the step of reducing using a reducing agent (S114). For example, the rare earth element may include at least one of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, or Lu have. The metal element may include at least one of Fe, Co, or Ni. The reducing agent may include at least one of Ca or CaH ₂ .

More specifically, the base metal 100 may be prepared by reducing a base precursor containing Sm and Co to CaH ₂ . In this case, in the process of reducing the base precursor, Sm and Co form an SmCo compound, and CaO, a by-product of CaH ₂ , may be formed on the surface of the SmCo compound. Accordingly, the base metal 100 may include SmCo, which is a rare earth metal compound 110, and CaO, which is a calcium compound 120. That is, the base metal used in the method of plating the rare earth metal according to the embodiment may be a rare earth metal compound in which a by-product of a reducing agent containing Ca is generated on the surface as it is reduced through a reducing agent containing Ca.

1 and 4, a plating source including a calcium reactant, a first metal precursor, and a second metal precursor may be prepared (S120 ). The first metal precursor may include a first metal. The second metal precursor may include a second metal.

According to an embodiment, the first and second metals may have a lower ionization tendency than the calcium. For example, the first metal precursor may include Fe. Specifically, the first metal precursor may include iron nitrate hexahydrate (Fe(NO ₃ ) ₃ 9H ₂ O). For example, the second metal precursor may include Co. Specifically, the second metal precursor may include cobalt nitrate hexahydrate (Co(NO ₃ ) ₂ 6H ₂ O). In this case, in the plating step described later, the plating layer can be easily formed. More detailed description will be given later.

According to one embodiment, the plating source preparation step (S120) is a step of preparing a mixed solution by mixing ultrapure water and the calcium reactant (S122), and the first metal precursor in the mixed solution, and the second It may include the step of providing a metal precursor (S124). For example, the calcium reactant may include fluorine (F). Specifically, the calcium reactant may include at least one of NH ₄ F or HF.

According to one embodiment, the ratio of the first metal precursor and the second metal precursor provided in the mixed solution may be adjusted according to the composition of the metal alloy to be plated. Specifically, the ratio of the first metal precursor: second metal precursor provided in the mixed solution for plating of Fe ₇ Co ₃ may be 7:3.

In addition, the number of moles of the first metal included in the first metal precursor provided in the mixed solution, and the number of moles of the second metal included in the second metal precursor may be controlled. Specifically, the sum of the number of moles of the first metal included in the first metal precursor and the number of moles of the second metal included in the second metal precursor may be greater than 1 mmol and less than 75 mmol. In this case, the rare earth composite structure described later can be easily formed. Alternatively, when the sum of the number of moles of the first metal included in the first metal precursor and the number of moles of the second metal included in the second metal precursor is 1 mmol or less, the rare earth metal compound, the plating layer to be described later is easily Problems that do not form may occur. On the other hand, when the sum of the number of moles of the first metal included in the first metal precursor and the number of moles of the second metal included in the second metal precursor is 75 mmol or more, the acidity of the plating source is increased, and the base metal is damaged. Problems may occur.

According to one embodiment, the plating source may further include a pH adjusting agent, an antioxidant, and a stabilizer. For example, the pH adjusting agent is any one of sulfuric acid (H ₂ SO ₄ ), hydrochloric acid (HCl), nitric acid (HNO ₃ ), potassium hydroxide (KOH), sodium hydroxide (NaOH), and ammonia water (NH ₄ OH). It may include. The antioxidant, catechol (catechol), hydroquinone (hydroquinone), ascorbic acid (ascorbic acid), and may include any one of ascorbic acid salts (ascorbic acide). The stabilizer, formaldehyde (HCHO), sodium borohydride (NaBH ₄ ), citrate (citrate), polyacrylamide (PA), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), and polyethylene glycol ( PEG).

5 is a flow chart specifically explaining the plating step of the plating method of the rare earth metal according to an embodiment of the present invention, FIG. 6 is a view showing a plating process of the rare earth metal according to an embodiment of the present invention, and FIG. It is a view showing a rare earth composite structure according to an embodiment of the invention.

1 and 5 to 7, the first metal (M ₁ ) on the surface of the rare earth metal compound 110 by providing the base metal 100 with the plating source 200, and An alloy of the second metal (M ₂ ) may be plated (S130). For example, the base metal 100 may be provided by a method immersed in the plating source 200.

According to one embodiment, the plating step (S130), forming a pre-plating layer 310 on the rare-earth metal compound 110 (S132), and reducing the pre-plating layer 310 to reduce the rare earth On the metal compound 110, a step (S134) of forming a plating layer 320 may be included. Hereinafter, each step is explained in more detail.

The forming of the preliminary plating layer 310 (S132) may be performed by a method of reacting the plating source 200 with the base metal 100. When the base metal 100 is reacted with the plating source 200, the calcium compound contained in the base metal 100 may be dissociated into calcium anions and electrons. The dissociated calcium anion may be reacted with the calcium reactant (CaR) included in the plating source 200. Accordingly, a functional material (FM) may be formed. More specifically, the dissociated calcium anion may react with a fluorine (F) cation contained in the calcium reactant (CaR) to form a calcium fluoride (CaF ₂ ) ionic compound. Accordingly, the functional material (FM) may include a calcium fluoride (CaF ₂ ) ionic compound. The functional material FM may improve electrical resistance, corrosion resistance, and the like of the rare earth composite structure described later.

On the other hand, the dissociated electrons may react with the first metal (M ₁ ) of the first metal precursor included in the plating source 200 and the second metal (M ₂ ) of the second metal precursor. . Accordingly, an alloy (M ₁ +M ₂ alloy) of the first and second metals may be formed. In addition, when the first metal (M ₁ ) and the second metal (M ₂ ) are reacted with the electron, the first and second metals (M ₁ +M ₂ alloy) as well as the first Alloy oxides of the first and second metals (M ₁ +M ₂ oxide) may be formed. For example, when the first metal M ₁ includes Fe and the second metal M ₂ includes Co, FeCo and FeCo oxides may be formed.

The functional material FM, the first and second metal alloys (M ₁ +M ₂ alloy), and the first and second metal alloy oxides (M ₁ +M ₂ oxide) are the rare earth metal compounds It may be formed on the (110) surface. Accordingly, the functional material (FM) on the surface of the rare earth metal compound 110, the alloys of the first and second metals (M ₁ +M ₂ alloy), and the alloy oxides of the first and second metals ( M ₁ +M ₂ oxide) may be formed of the pre-plating layer 310.

That is, when the base metal 100 is provided with the plating source 200, as described above, as the first and second metals M ₁ and M ₂ have a lower ionization tendency than the calcium, the Calcium compounds can dissociate calcium anions, and electrons. Calcium dissociated from the calcium compound reacts with the calcium reactant to form the functional material (FM), and at the same time, electrons dissociated from the fraudulent calcium compound are combined with the first and second metals (M ₁ , M ₂ ). By reacting, the rare earth metal compound 110 may be plated with an alloy of the first and second metals (M ₁ +M ₂ alloy) on the surface.

The forming of the plating layer 320 (S134) may be performed by reducing the pre-plating layer 310. For example, the pre-plating layer 310 may be reduced by heat treatment in a H ₂ atmosphere at a temperature of 700° C. for 30 minutes. When the pre-plating layer 310 is reduced, the first and second metal alloy oxides (M ₁ +M ₂ oxide) included in the pre-plating layer 310 are alloys of the first and second metals ( M ₁ +M ₂ alloy).

Accordingly, the rare earth composite structure 400 manufactured by the method of plating the rare earth metal according to the embodiment may be manufactured. That is, the rare earth composite structure 400 includes the rare earth metal compound 110 and the plating layer 320 surrounding the rare earth metal compound 110, wherein the plating layer 320 includes the first metal and the second. It may include an alloy of metal (M ₁ +M ₂ alloy), and the functional material (FM). In addition, the content of the first metal and the second metal alloy (M ₁ +M ₂ alloy) in the plating layer 320 may be greater than the content of the functional material (FM).

When the pre-plating layer 310 includes the first and second metal alloy oxides (M ₁ +M ₂ oxide), oxidation occurs in an atmospheric atmosphere, and the pre-plating layer 310 is corroded. Can be. However, when the pre-plating layer 310 is reduced, the first and second metal alloy oxides (M ₁ +M ₂ oxide) are converted to the first and second metal alloys (M ₁ +M ₂ alloy). As it is reduced, the phenomenon that the plating layer 320 is oxidized and corroded in an atmosphere can be prevented.

In describing the method of plating the rare earth metal according to the embodiment, the first and second metal alloys (M ₁ +M ₂ alloy) through the plating source 200 including the first and second metal precursors ) Is plated as an example, but a single metal may be plated on the rare earth metal compound through a plating source including a single metal precursor. Further, the first to third metal alloys may be plated through a plating source including the first to third metal precursors. That is, the type of metal precursor included in the plating source 200 and the alloy plated thereby is not limited.

As described above, the base metal used in the method of plating the rare earth metal according to the embodiment may be a rare earth metal compound formed by-product of a reducing agent containing Ca. In order to plate other metals on the rare earth metal compound formed with these Ca by-products, complex processes such as a removal process of Ca by-product, a degreasing and pickling process, and a plating process have been required. However, since each of the processes can damage the base rare earth metal compound, it is difficult to obtain an excellent quality rare earth composite structure.

More specifically, the Ca byproduct removal process is a process for removing Ca byproducts formed on the surface of the rare earth metal compound, and may be performed by a method of washing with ultrapure water or weak acid. However, in this washing process, a rare earth metal compound may be damaged or a problem in which a calcium passivation film (Ca(OH) ₂ ) is generated may occur.

In addition, the degreasing and pickling process is a process of removing oxides, foreign substances, oils, and the like present on the surface of the rare earth metal compound, and may be performed by washing with an acid or alkali surfactant. However, a rare earth metal compound may be damaged by an acid or alkali surfactant, or a rare earth metal compound may be contaminated by foreign substances that cannot be removed.

In addition, an electroless plating method was mainly used as a plating process. In order to plate through the electroless plating method, a sensitizing and activating process using a catalyst and a plating process using an electroless plating solution are required.

The sensitizing and activating process using a catalyst is a process of coating catalyst particles on the surface of a rare earth metal compound, and may be performed by a method of applying a platinum (Pd)-tin (Sn) catalyst. However, in order to apply a platinum (Pd)-tin (Sn) catalyst, as a strong acid hydrochloric acid (HCl) is used as a precursor, not only can the rare earth metal compound be damaged, but also the filtration and washing process of the rare earth metal compound Problems may be required several times.

In addition, the plating process using an electroless plating solution is a process in which metal ions plated on a rare earth metal compound are combined with a platinum (Pd)-tin (Sn) catalyst to provide a rare earth metal compound with a precursor containing a metal to be plated. Method. However, in the case of a precursor containing a metal to be plated, it exhibits strong basicity. As a rare earth metal compound catalyzed by a strong acid reacts with a strong base, a problem that the rare earth metal compound is damaged may occur.

Alternatively, the method of plating a rare earth metal according to an embodiment of the present invention comprises the steps of preparing the base metal 100 including the calcium (Ca) compound 120 and the rare earth metal compound 110, the The plating source 200 including the calcium reactant (CaR), the first metal precursor including the first metal (M ₁ ), and the second metal precursor including the second metal (M ₂ ) Preparing, and providing the plating source 200 to the base metal 100, while reacting the calcium contained in the calcium compound 120 with the calcium reactant (CaR), the rare earth metal compound Plating an alloy of the first metal and the second metal (M ₁ +M ₂ alloy) on the (110) surface may be included.

That is, the method of plating the rare earth metal according to the embodiment may be plated using a by-product without removing the by-product of a reducing agent containing Ca. Accordingly, a method of plating rare earth metals may be provided as a process of removing Ca by-products and a simplified process without catalytic treatment.

As described above, the rare earth metal plating solution, the rare earth composite structure, and the rare earth metal plating method according to embodiments of the present invention have been described. Hereinafter, specific experimental examples and property evaluation results for the rare earth metal plating solution, the rare earth composite structure, and the rare earth metal plating method according to the above embodiment will be described.

Preparation of base metal according to the embodiment

An oxide nanopowder composed of SmCoO ₃ , Sm ₂ O ₃ and Co ₃ O ₄ (purity>99.9%) is prepared. The prepared oxide nanopowder was mixed with a CaH ₂ reducing agent and CaH ₂ : nanopowder = 2: 1 in a volume ratio, and then heated in an inert atmosphere at a temperature of 700° C. for 3 hours. The heated powder was dried in a vacuum oven at 70° C. to prepare a base metal according to the above embodiment in which CaO by-products were formed on the SmCo rare earth metal compound.

The chemical composition ratio of the base metal according to the embodiment is summarized in <Table 1> below. The chemical composition ratio was measured by XRF equipment.

division	Content (wt%)
Co	62.563
Sm	20.268
Ca	16.746
Cl	0.203
S	0.107
P	0.063
Si	0.029
Cr	0.021

Plating source production according to the embodiment

2 mL of 40 w/v% ammonium fluoride (NH ₄ F) was added to 72 mL of ultrapure water and mixed in a stirrer to prepare a mixed solution. Thereafter, the ratio of iron nitrate hexahydrate (Fe(NO ₃ ) ₃ 9H ₂ O) and cobalt nitrate hexahydrate (Co(NO ₃ ) ₂ 6H ₂ O) is set to Fe:Co=7:3, which is then added to the mixed solution. Provided, the sum of the number of moles of iron nitrate hexahydrate (Fe(NO ₃ ) ₃ 9H ₂ O) and cobalt nitrate hexahydrate (Co(NO ₃ ) ₂ 6H ₂ O) is 0 mmol, 1 mmol, 5 mmol, 10 mmol , 15 mmol, 30 mmol, 50 mmol, and 75 mmol were controlled to prepare plating sources according to Examples 1 to 8, respectively.

In addition, it is prepared through the manufacturing method of the plating sources according to Examples 1 to 8, but 1 mL of ammonium fluoride (NH ₄ F) is injected and iron nitrate 9 hydrate (Fe(NO ₃ ) ₃ 9H ₂ O) and cobalt nitric acid A plating source according to Example 9 in which the sum of the number of moles of hexahydrate (Co(NO ₃ ) ₂ 6H ₂ O) was controlled to 50 mmol was also prepared.

In addition, it is prepared through the manufacturing method of the plating source according to Examples 1 to 8, but ammonium fluoride (NH ₄ F) is not injected, iron nitrate 9 hydrate (Fe(NO ₃ ) ₃ 9H ₂ O) and cobalt nitric acid A plating source according to Example 10 in which the sum of the number of moles of hexahydrate (Co(NO ₃ ) ₂ 6H ₂ O) was controlled to 50 mmol was also prepared.

Materials used in the production of the plating sources according to Examples 1 to 10 are summarized through <Table 2> below.

division	The amount of NH 4 F injected	The number of moles of Fe precursor and Co precursor
Example 1	2 mL	0 mmol
Example 2	2 mL	1 mmol
Example 3	2 mL	5 mmol
Example 4	2 mL	10 mmol
Example 5	2 mL	15 mmol
Example 6	2 mL	30 mmol
Example 7	2 mL	50 mmol
Example 8	2 mL	75 mmol
Example 9	1 mL	50 mmol
Example 10	0 mL	50 mmol

Preparation of rare earth composite structures according to embodiments

0.05 g of base metal according to the embodiment and a plating source according to Examples 1 to 10 are prepared. The prepared base metals were immersed in the plating sources according to Examples 1 to 10, respectively, stirred using a spatula, and then subjected to a plating reaction for 10 minutes at room temperature. Thereafter, the plated SmCo powder was filtered through centrifugation, washed several times with ultrapure water and methanol, and then sufficiently dried in a vacuum oven at a temperature of 70°C. In addition, the dried structure was reduced in a H ₂ atmosphere at a temperature of 700° C. for a period of 30 minutes to prepare a rare earth composite structure according to Examples 1 to 10 in which an FeCo pre-plated layer was formed on the SmCo rare earth metal compound.

Plating results of the rare earth composite structure according to the above embodiments are summarized through <Table 3> below, and chemical composition ratios of the rare earth composite structure according to Example 1 are summarized through <Table 4> below.

division	Plating result
Example 1	CaF 2 generation
Example 3	CaF 2 production, FeCo production
Example 4	CaF 2 production, FeCo production
Example 6	CaF 2 production, FeCo production
Example 7	CaF 2 production, FeCo production
Example 8	CaF 2 production, FeCo production, SmCo dissolution
Example 9	CaF 2 production, FeCo production, SmCo dissolution
Example 10	FeCo generation, SmCo dissolution

division	Content (wt%)
Co	71.107
Sm	25.495
Ca	1.144
F	1.006
Fe	0.273
Cl	0.201
S	0.119
P	0.061

8 is a photograph of a base metal according to an embodiment of the present invention.

8, the base metal according to the above embodiment was photographed by SEM (Scanning Electron Microscope). As can be seen in FIG. 8, it was confirmed that the base metal according to the above embodiment formed CaO, a by-product of the CaH ₂ reducing agent, on the surface of the SmCo rare earth metal compound.

9 is a photograph of a rare earth composite structure according to Example 1 of the present invention.

Referring to FIG. 9, before and after the rare earth composite structure according to Example 1 is reduced, SEM images are respectively shown in FIGS. 9(a) and 9(b). As can be seen from (a) and (b) of FIG. 9, the rare earth composite structure according to Example 1 in which the Fe precursor and the Co precursor are not provided are SmCo rare earth as the base metal according to the embodiment shown in FIG. It was confirmed that CaO was formed on the metal compound.

10 is a photograph of a rare earth composite structure according to Example 2 of the present invention. Referring to FIG. 10, SEM images of the rare earth composite structure according to Example 2 before and after reduction are respectively shown in FIGS. 10A and 10B. As can be seen from (a) and (b) of FIG. 10, it was confirmed that the CaF ₂ particles were formed on the SmCo rare earth metal compound in the rare earth composite structure according to Example 2.

11 to 15 are photographs of rare earth composite structures according to Examples 3 to 7 of the present invention. 11 to 15, before and after the rare earth composite structures according to Examples 3 to 7 are reduced, SEM images are respectively shown in FIGS. 11 to 15 (a) and (b). As can be seen in FIGS. 11 to 15, it was confirmed that the rare earth composite structures according to Examples 3 to 7 were formed with a plating layer containing FeCo and CaF ₂ on the SmCo rare earth metal compound.

16 is a photograph of a rare earth composite structure according to Example 8 of the present invention. Referring to FIG. 16, SEM images of before and after the rare earth composite structure according to Example 8 were reduced are shown in FIGS. 16A and 16B. As can be seen in Figure 16, the rare earth composite structure according to Example 8, it was found that the plating layer containing FeCo and CaF ₂ was formed, but the SmCo rare earth metal compound was damaged.

10 to 16, in order to easily form a plating layer containing FeCo and CaF ₂ on the SmCo rare earth metal compound, the molar sum of Fe precursors and Co precursors included in the plating source exceeds 1 mmol 75 It can be seen that it should be controlled to less than mmol.

17 and 18 are diagrams showing components of a rare earth composite structure according to Example 7 of the present invention.

17 and 18, the rare earth composite structure according to Example 6 was shown by qualitative analysis using a scanning electron microscope/energy dispersive X-ray detection spectrometer (SEM/EDS). As can be seen in FIGS. 17 and 18, it was confirmed that the rare earth composite structure according to Example 7 includes Sm, Fe, Ca, and F.

19 is a graph showing the configuration of a rare earth composite structure according to embodiments of the present invention.

19 (a) to (e), for the rare earth composite structures according to Example 1, Example 4, Example 6, Example 7, and Example 8 to 2 theta (deg.) Relative Intensity (au) was measured, and an X-ray diffraction pattern was displayed.

As can be seen in Figure 19 (a), the rare earth composite structure according to Example 1, the pattern for Sm ₂ Co ₁₇ is confirmed, but the pattern for FeCo and CaF ₂ is not confirmed, plating is made easily I could confirm that I didn't lose. On the other hand, as can be seen from (b) to (e) of FIG. 19, the rare earth composite structures according to Example 4, Example 6, Example 7, and Example 8, the pattern for CaF ₂ and Fe ₁₁ Co _The pattern for ₅ was confirmed, and it was confirmed that plating was easily performed.

20 is a graph showing the configuration of a base metal and a rare earth composite structure according to Example 6 of the present invention.

20 (a) to (c), the base metal according to the embodiment, the rare earth composite structure according to Example 6 before reduction, and the rare earth composite structure according to Example 6 after reduction 2 Relative Intensity (au) according to theta (deg.) was measured to show an X-ray diffraction pattern.

As can be seen in Figure 20 (a), the base metal according to the embodiment is seen as a pattern for CaO and a pattern for Sm ₂ Co ₁₇ appear, Sm ₂ Co ₁₇ CaO by-product formed on the rare earth metal compound Could know.

As can be seen in FIG. 20(b), the rare earth composite structure according to Example 6 before reduction is not only a pattern for Sm ₂ Co ₁₇ , a pattern for CaF ₂ , and a pattern for Fe ₁₁ Co ₅ , ( Fe,Co) It was confirmed that the pattern for ₇ O ₁₁ also appeared, FeCo alloy oxide was formed.

20(c), the rare earth composite structure according to Example 6 after reduction has a pattern for Sm ₂ Co ₁₇ , a pattern for CaF ₂ , and a pattern for Fe ₁₁ Co ₅ , ( Fe,Co) It was confirmed that the pattern for ₇ O ₁₁ does not appear, FeCo alloy oxide was reduced to FeCo alloy.

As described above, the present invention has been described in detail using preferred embodiments, but the scope of the present invention is not limited to specific embodiments, and should be interpreted by the appended claims. In addition, those skilled in the art should understand that many modifications and variations are possible without departing from the scope of the present invention.

The rare earth metal plating solution according to an embodiment of the present invention may be used for plating a metal structure containing rare earth.

Claims (14)

1. Preparing a base metal including a calcium (Ca) compound and a rare earth metal compound;

   Preparing a plating source comprising a calcium reactant, a first metal precursor comprising a first metal, and a second metal precursor comprising a second metal; And

   Providing the plating source to the base metal, reacting the calcium contained in the calcium compound with the calcium reactant, and simultaneously plating the first metal and the second metal alloy on the rare earth metal compound surface. A method of plating a rare earth metal comprising a step.
2. According to claim 1,

   When the base metal is provided with the plating source, the calcium compound is dissociated into calcium ions and electrons,

   The first metal of the first metal precursor, and the second metal of the second metal precursor is reacted with the electrons, a method of plating a rare earth metal comprising forming an alloy of the first and second metals.
3. According to claim 2,

   The calcium ion is a method of plating a rare earth metal comprising reacting with the calcium reactant to form a functional material.
4. According to claim 3,

   The calcium reactant includes fluorine (F), and the functional material comprises a reaction of a fluorine anion and a calcium cation, a method for plating a rare earth metal.
5. According to claim 3,

   The calcium reactant is a method of plating rare earth metals containing either NH ₄ F or HF.
6. According to claim 1,

   The step of preparing the base metal,

   Preparing a base precursor comprising a rare earth element and a metal element; And

   A method of plating a rare earth metal comprising the step of reducing the base precursor using a reducing agent containing calcium.
7. The method of claim 6,

   The rare earth element is plating of rare earth metals including at least one of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, or Lu Way.
8. According to claim 1,

   The calcium compound is a method of plating a rare earth metal containing calcium oxide (CaO).
9. According to claim 1,

   The step of preparing the plating source,

   Preparing a mixed solution by mixing ultrapure water and the calcium reactant;

   Providing the first metal precursor, and the second metal precursor to the mixed solution,

   A method of plating rare earth metals comprising different proportions of the first metal precursor and the second metal precursor provided in the mixed solution.
10. The method of claim 9,

    A method of plating a rare earth metal, wherein the sum of the number of moles of the first metal included in the first metal precursor and the number of moles of the second metal included in the second metal precursor is greater than 1 mmol and less than 75 mmol.
11. According to claim 1,

    The plating step,

    The base metal is reacted with the plating source, and on the rare earth metal compound, a functional material in which the calcium and the calcium reactant are reacted, an alloy of the first and second metals, and an alloy of the first and second metals Forming a pre-plating layer containing oxide; And

    And reducing the preliminary plating layer to form a plating layer comprising the functional material and an alloy of the first and second metals on the rare earth metal compound.
12. A plating solution of a base metal containing a calcium (Ca) compound and a rare earth compound,

    The plating solution,

    Calcium reactants containing fluorine (F);

    A first metal precursor including a first metal having a lower ionization tendency than the calcium; And

    A rare earth metal plating solution comprising a second metal precursor containing a second metal having a lower ionization tendency than the calcium.
13. Rare earth metal compounds; And

    The first metal and the alloy of the second metal, and a functional material comprising a fluorine (F), and a plating layer surrounding the rare earth metal compound; includes,

    The rare earth composite structure in which the content of the alloy in the plating layer contains more than the content of the functional material.
14. The method of claim 13,

    The rare earth composite structure comprising the alloy, and the functional material produced at the same time.

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