Translucent magnetic material, optical element and optical device

Abstract

To provide a translucent magnetic material having excellent optical characteristics.SOLUTION: A translucent magnetic material comprises a plurality of magnetic particles which include a plurality of FeCo particles, and a translucent material in which the plurality of magnetic particles are dispersed. The translucent material includes a ceramic material which contains a compound of fluorine and at least one element from among group III, group IV and group V, and a metal material which is disposed in a region between the plurality of FeCo particles and the ceramic material.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a light-transmitting magnetic material, an optical element having the light-transmitting magnetic material, and an optical device having the optical element. [Background technology]

[0002] Nanogranular materials are known as an example of transparent magnetic materials. Nanogranular materials have a structure in which nanometer-sized fine metal particles, so-called granules, are uniformly dispersed in a transparent material. Examples of such nanogranular materials are disclosed in Patent Documents 1 and 2. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-27222 [Patent Document 2] JP 2017-98423 A Summary of the Invention [Problem to be solved by the invention]

[0004] One aspect of the present disclosure provides a light-transmitting magnetic material having excellent optical properties. [Means for solving the problem]

[0005] A translucent magnetic material according to one embodiment of the present disclosure includes a plurality of magnetic particles including a plurality of FeCo particles, and a translucent material having the plurality of magnetic particles dispersed therein, the translucent material having a ceramic material including a compound of at least one element of groups III, IV, and V and fluorine, and a metal material located in a region between the plurality of FeCo particles and the first material. Effect of the Invention

[0006] According to one aspect of the present disclosure, a light-transmitting magnetic material having excellent optical properties can be realized. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram illustrating an outline of a light-transmitting magnetic material according to one embodiment of the present disclosure. [Diagram 2] FIG. 1 is a schematic diagram showing an example of a configuration of a film forming apparatus. [Diagram 3] 5A and 5B are schematic diagrams illustrating the operation of the film forming apparatus. [Figure 4] FIG. 13 is a diagram showing an example of a molecular dynamics simulation of a film formation process of a light-transmitting magnetic material. [Diagram 5] 11 is a graph showing an example of a simulation result regarding the state of electrons in a light-transmitting magnetic material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [Embodiment 1] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present disclosure will now be described in detail. The sizes of components in the drawings do not necessarily correspond to the actual sizes of the components.

[0009] (Structure of translucent magnetic material) FIG. 1 is a schematic diagram showing an outline of a light-transmitting magnetic material 1 according to one embodiment of the present disclosure. As shown in FIG. 1, the light-transmitting magnetic material 1 has a light-transmitting material 10 and a magnetic material disposed in the light-transmitting material 10. The light-transmitting magnetic material 1 includes a plurality of magnetic particles 20 as the magnetic material. The light-transmitting material 10 may be contained in the light-transmitting magnetic material 1 in a range of, for example, 30% or more and 90% or less. The plurality of magnetic particles 20 may be contained in the light-transmitting magnetic material 1 in a range of, for example, 10% or more and 70% or less.

[0010] The magnetic particles 20 are, for example, metal particles. In this embodiment, the magnetic particles 20 are FeCo particles 20. That is, a plurality of FeCo particles 20 may be dispersed in the light-transmitting material 10. The plurality of magnetic particles 20 may be called granules. The light-transmitting magnetic material 1 in which the granules are dispersed in the light-transmitting material 10 may also be called a nanogranular material. The magnetic particles 20 may have magnetism as a whole, and may contain a nonmagnetic material as a constituent. For example, atoms of a nonmagnetic material may be bonded to dangling bonds on the surface of the magnetic particles 20.

[0011] A part of the magnetic particle 20 may have an oxidized compound, that is, a compound produced by an oxidation-reduction reaction. That is, a part of the atoms constituting the magnetic particle 20 may be oxidized to lose electrons and form a compound by chemically reacting with other atoms. For example, when the magnetic particle 20 is an FeCo particle 20, the Fe 2+ Or Co 2+ may be bonded to other negative ions. In the present disclosure, a compound produced by an oxidation-reduction reaction may be referred to as an oxidation-reduction reaction compound.

[0012] The magnetic particles 20 are fine particles of metal. The average particle diameter of the magnetic particles 20 may be 50 nm or less. By setting the average particle diameter of the magnetic particles 20 to 50 nm or less, the light-transmitting magnetic material 1 can have good light transmittance. The average particle diameter of the magnetic particles 20 may be 10 nm or more. By setting the average particle diameter of the magnetic particles 20 to 10 nm or more, the magnetic particles 20 can easily retain their magnetism. These average particle diameters can be measured, for example, by calculating the average of a plurality of particle diameters observed by a TEM (Transmission Electron Microscope).

[0013] The light-transmitting material 10 includes a first material 11 having light-transmitting properties. The first material 11 may be, for example, a ceramic. The ceramic may be, for example, an oxide, a fluoride, or a nitride. The ceramic may be, for example, a material having radical electrons. The ceramic may be, for example, a semiconductor material.

[0014] In this embodiment, the light-transmitting material 10 may contain, as the first material 11, a compound of at least one element of group III, group IV, and group V and fluorine. Specifically, the first material 11 may contain, for example, any one of MgF2, AlF3, YF3, ScF3, TiF4, ZrF4, VF5, and NbF5. The ceramic may be a single material or a mixture of multiple types of materials. Specifically, the ceramic may be a mixture of two or more materials of MgF2, AlF3, YF3, ScF3, TiF4, ZrF4, VF5, and NbF5. The first material 11 may exist in a non-crystalline or amorphous state.

[0015] The first material 11 of the light-transmitting material 10 is disposed so as to be located in the region between each of the magnetic particles 20. The first material 11 may be filled in the region between each of the magnetic particles 20 so as to separate or separate the multiple magnetic particles 20 so as not to contact each other. In addition, the magnetic particles 20 and the first material 11 may be polarized. In this embodiment, the first material 11 is composed of MgF2, AlF3, YF3, ScF3, TiF4, ZrF4, VF5, or NbF5, excluding unintended impurities. That is, the first material 11 has a translucent material such as MgF2, AlF3, YF3, ScF3, TiF4, ZrF4, VF5, or NbF5 as a main component. The main component refers to, for example, a component that becomes the base material of the first material 11. The main component may also refer to, for example, a component that is contained in the largest amount among the materials that constitute the first material 11. The main component may also refer to, for example, a component that has the greatest effect on the characteristics of the first material 11. The first material 11 may be contained in a range of, for example, 30 volume % or more and 90 volume % or less of the translucent material 10.

[0016] The light-transmitting material 10 has light-transmitting properties because it is mainly composed of the first material 11. The light-transmitting material 10 only needs to have sufficient transmittance for at least one of visible light and infrared light depending on the conditions of use, and does not need to completely transmit light. In addition, the light-transmitting material 10 only needs to have light-transmitting properties as a whole, and a non-light-transmitting material may be included as a part of the materials constituting the light-transmitting material 10.

[0017] The light-transmitting material 10 may further include a second material 12. The second material includes a metal material. The light-transmitting material 10 may include a smaller amount of the second material 12 than the first material 11. The light-transmitting material 10 may include the second material 12 as a subcomponent. The second material 12 included in the light-transmitting material 10 may be a part of the composition of the first material 11, or may not be a part of the composition of the material having light transmissibility. The second material 12 may be included in the light-transmitting material 10 in a range of, for example, 10% or more and 60% or less of the light-transmitting material 10.

[0018] The second material 12 may be located around the surface of the magnetic particle 20. The second material 12 may be located in the vicinity of the magnetic particle 20. The second material 12 may be attached to the surface of the magnetic particle 20. The second material 12 may be located between the first material 11 and the magnetic particle 20. The second material 12 may exist as a plurality of metal atoms metallically bonded to each other, as a metal atom covalently bonded to atoms constituting the magnetic particle 20, or as a single metal atom in an ionized state.

[0019] The second material 12 may be disposed in the form of a film on the surface of the magnetic particle 20. The second material 12 may also be disposed in a speckled pattern on the surface of the magnetic particle 20. When the second material 12 exists as the above-mentioned metal film, the metal film has a thickness of, for example, 1 nm or more and 10 nm or less.

[0020] As described above, the magnetic particle 20 may have an oxide compound. A part of the surface layer of the magnetic particle 20 may be oxidized. The oxide compound may be generated by an oxidation-reduction reaction between the magnetic particle 20 and the first material 11 located in the vicinity of the magnetic particle 20. The magnetic particle 20 may have a compound other than the oxide compound, for example, which is a part of the composition of the magnetic particle 20 and a part of the composition of the first material 11. Specifically, when the first material 11 is a fluoride, the oxide compound may be a fluoride different from the first material 11. Also, when the first material 11 is a nitride, the oxide compound may be a nitride different from the first material. Also, when the first material 11 is an oxide, the oxide compound may be an oxide different from the first material.

[0021] In this embodiment, since the first material 11 is MgF2, AlF3, YF3, ScF3, TiF4, ZrF4, VF5, and NbF5, the magnetic particle 20 may have Fe-F and Co-F by undergoing an oxidation-reduction reaction between MgF2, AlF3, YF3, ScF3, TiF4, ZrF4, VF5, and NbF5. That is, the magnetic particle 20 may have at least one of Fe and Co bonded to a part of the composition constituting the first material 11. Fe-F may exist in the form of at least one of FeF, FeF2, and FeF3. Also, Co-F may exist in the form of CoF2.

[0022] A part of the second material 12 may be in contact with the magnetic particles 20. Another part of the second material 12 may be in contact with an oxide compound of the magnetic particles 20 or another compound.

[0023] The oxide compound of the magnetic particle 20 may cover the surface of the body of the magnetic particle 20 in a film shape so as to constitute the surface layer of the magnetic particle 20, or may be arranged in a spotted pattern on the surface of the body so as to constitute a part of the surface layer. The oxide compound of the material of the magnetic particle 20 and the first material 11 may be present as the third material 13 in the light-transmitting material 10. In other words, the light-transmitting material 10 may have the third material 13 as a subcomponent. The third material 13 may be arranged around the magnetic particle 20 as shown in FIG. 1, or may be mixed with the second material 12. The third material 13 may be arranged between the magnetic particle 20 and the first material 11, or between the magnetic particle 20 and the second material 12. In addition, the oxide compound that becomes a part of the surface of the magnetic particle 20 and the oxide compound in the light-transmitting material 10 may be located at the boundary between the magnetic particle 20 and the light-transmitting material 10 so as to aggregate with each other. The amount of the oxide compound contained in the light-transmitting material 10 may be the same as that of the second material 12, for example.

[0024] On the other hand, a part of the second material 12 may be generated by reducing the magnetic particle 20. In this case, the reduced product is located on the surface of the magnetic particle 20 and in the vicinity thereof. In this embodiment, when the first material 11 includes MgF2, the reduced product may include Mg (magnesium). For example, when the first material 11 includes AlF3, the reduced product may include Al (aluminum). For example, when the first material 11 includes YF3, the reduced product may include Y (yttrium). For example, when the first material 11 includes ScF3, the reduced product may include Sc (scandium). For example, when the first material 11 includes TiF4, the reduced product may include Ti (titanium). For example, when the first material 11 includes ZrF4, the reduced product may include Zr (zirconium). For example, when the first material 11 includes VF5, the reduced product may include V (vanadium). Furthermore, for example, when the first material 11 contains NbF5, the reduced product may contain Nb (niobium). In this case, the reduced product may cover the surface of the magnetic particle 20 in the form of a film, or may be arranged in a speckled pattern on the surface of the magnetic particle 20. Furthermore, the reduced product may be the second material 12 contained in the light-transmitting material 10.

[0025] In such a light-transmitting magnetic material 1, the density of the outermost electrons of Fe, Co, and F increases due to the presence of oxide compounds of the magnetic particles 20, such as Fe-F and Co-F. In addition, an increase in magnetic moment occurs in Mg, Al, Y, Sc, Ti, Zr, V, or Nb contained in the second material 12. Specifically, the spin magnetic moment increases in Mg and Al, and the orbital magnetic moment and spin magnetic moment increase in Y, Sc, Ti, Zr, V, and Nb. As a result, the magneto-optical effect that rotates the polarization plane of light incident on the light-transmitting magnetic material 1, particularly the second material 12, increases. Therefore, the light-transmitting magnetic material 1 having the second material 12 has excellent optical properties.

[0026] The magnetic moment is expressed as the sum of the orbital magnetic moment and the spin magnetic moment. Therefore, in order to obtain the light-transmitting magnetic material 1 having an excellent magneto-optical effect, the metal fluoride contained in the first material 11 may be a metal fluoride in which not only the spin magnetic moment but also the orbital magnetic moment is increased by the electrons donated during the reduction reaction, and in particular, the metal fluoride in which the electrons donated during the reduction reaction enter an orbital having a higher orbital magnetic moment. For example, the metal fluoride contained in the first material 11 may be a metal fluoride in which the electrons donated during the reduction reaction enter a d orbital, and may be a compound of at least one element of group IV and group V and fluorine. In another example, the metal fluoride contained in the first material 11 may be a material in which the electrons donated during the reduction reaction enter a d orbital and the electrons do not enter a d orbital before reduction, and specifically, may be YF3, ScF3, TiF4, ZrF4, VF5, and NbF5.

[0027] For example, in the light-transmitting magnetic material 1, 15 mol % or more of the Fe contained in the FeCo particles 20 may exist as Fe-F. Also, in the light-transmitting magnetic material 1, 15 mol % or more of the Co contained in the FeCo particles 20 may exist as Co-F. The form and ratio of the oxide compound can be measured by, for example, XPS (X-ray Photoelectron Spectroscopy) or the like.

[0028] (Method of manufacturing light-transmitting magnetic material) The light-transmitting magnetic material 1 may be manufactured by, for example, sputtering deposition. An example of a method for manufacturing the light-transmitting magnetic material 1 will be described below.

[0029] FIG. 2 is a schematic diagram showing an example of the configuration of a film forming apparatus 100. The film forming apparatus 100 may be an apparatus that forms a film of a light-transmitting magnetic material 1 by sputtering film formation. As shown in FIG. 2, the film forming apparatus 100 may include a vacuum chamber 110, a cathode unit 120, and a power supply 130. The film forming apparatus 100 is an apparatus that deposits atoms contained in a target 220 on a substrate 210 by sputtering. There are no particular limitations on the material of the substrate 210 as long as it is unlikely to react with the atoms deposited by sputtering. The material of the target 220 will be described later.

[0030] The vacuum chamber 110 may be a chamber capable of creating a vacuum inside. The vacuum chamber 110 may be made of a conductor. The vacuum chamber 110 may be grounded.

[0031] The vacuum chamber 110 may have an opening 111. The cathode section 120 can be fitted into the opening 111 in an airtight manner. The vacuum chamber 110 may further have a port 112 to which a vacuum pump can be connected. With the cathode section 120 fitted into the opening 111, the inside of the vacuum chamber 110 can be evacuated by a vacuum pump (not shown) connected to the port 112.

[0032] The vacuum chamber 110 may further include a gas introduction system 113. The gas introduction system 113 introduces a gas at a constant flow rate into the vacuum chamber 110 in a vacuum state, thereby creating an atmosphere at a constant pressure according to the flow rate inside the vacuum chamber 110. The gas introduced by the gas introduction system 113 may be an inert gas, such as Ar.

[0033] The vacuum chamber 110 may further include a substrate holder 115. The substrate holder 115 can hold a substrate 210 on which the light-transmitting magnetic material 1 is formed. In a state in which the cathode portion 120 is fitted into the opening 111, the substrate holder 115 and the cathode portion 120 may face each other.

[0034] The substrate holder 115 may be equipped with a heater (not shown). By heating the substrate 210 with the heater during film formation, the temperature during film formation of the light-transmitting magnetic material 1 can be controlled. In addition, by heating the substrate 210 on which the light-transmitting magnetic material 1 has been formed after film formation, the crystallinity of the light-transmitting magnetic material 1 can be improved.

[0035] The cathode section 120 may be a section that functions as a cathode in sputtering film formation. A target 220 may be disposed on the cathode section 120. Specifically, the target 220 may be bonded to a back plate 231. The back plate 231 may be formed of, for example, copper. The back plate 231 may be disposed on the cathode section 120, whereby the target 220 may be disposed on the cathode section 120.

[0036] The cathode section 120 may include a first magnet 121 and a second magnet 122 surrounding the first magnet 121. For example, the first magnet 121 may be cylindrical, and the second magnet 122 may be a hollow cylinder surrounding the first magnet 121. The first magnet 121 and the second magnet 122 may be arranged such that the magnetic poles facing the target 220 are opposite to each other when the target 220 is arranged on the cathode section 120. For example, as shown in FIG. 2, the N pole of the first magnet 121 may face the target 220. Also, the S pole of the second magnet 122 may face the target 220.

[0037] The cathode unit 120 may further include a cooling mechanism 123 that circulates cooling water inside during film formation. The back plate 231 may be in contact with the cooling water while being disposed on the cathode unit 120 during film formation. The first magnet 121 and the second magnet 122 may be immersed in the cooling water during film formation.

[0038] The power supply 130 may be a power supply that inputs RF (Radio Frequency) to the cathode section 120. The power supply 130 may input, for example, 13.56 MHz power. As described above, the vacuum chamber 110 is grounded. Therefore, when the inside of the vacuum chamber 110 is in a vacuum state, a discharge occurs inside the vacuum chamber 110 by inputting RF to the cathode section 120. A matching box 131 that matches the impedance between the power supply 130 and the cathode section 120 may be provided between the power supply 130 and the cathode section 120.

[0039] 3 is a schematic diagram showing the operation of the film formation apparatus 100 during film formation. For simplicity, some of the components of the film formation apparatus 100 are omitted in FIG. 3. In the film formation apparatus 100, the substrate holder 115 may be rotatable around a rotation axis perpendicular to a surface on which the substrate 210 is disposed. The substrate 210 may be disposed at a position deviated from the rotation axis of the substrate holder 115. In this case, the substrate 210 is displaced as the substrate holder 115 rotates.

[0040] In the film forming apparatus 100, the cathode section 120 may include a first target 221 and a second target 222 as the target 220. The first target 221 may include AlF3, YF3, or MgF2. The second target 222 may include FeCo.

[0041] The substrate 210 may be displaced between a position facing the first target 221 and a position facing the second target 222 by rotation of the substrate holder 115. By depositing a film while displacing the substrate 210 between a position facing the first target 221 and a position facing the second target 222, a film of the light-transmitting magnetic material 1, which is a mixture of AlF3, YF3, or MgF2 and FeCo, is deposited.

[0042] However, in the film formation apparatus 100, the substrate holder 115 does not necessarily need to be rotatable around a rotation axis perpendicular to the surface on which the substrate 210 is disposed. For example, the substrate holder 115 may be reciprocating between a position facing the first target 221 and a position facing the second target 222. In this case as well, a film can be formed while displacing the substrate 210 between the position facing the first target 221 and the position facing the second target 222.

[0043] The power supply 130 may input different power to the cathode unit 120 when the substrate 210 is positioned facing the first target 221 and when the substrate 210 is positioned facing the second target 222. This makes it possible to adjust the ratio between the film formation rate by the first target 221 and the film formation rate by the second target 222.

[0044] A specific example of a film formation method using the film formation apparatus 100 is shown below. Each numerical value in the specific example is an example, and does not limit the film formation method according to the present disclosure. First, the substrate 210 is placed on the substrate holder 115, and the target 220 containing the material of the light-transmitting magnetic material 1 is placed on the cathode part 120. The cathode part 120 is then fitted into the opening 111 of the vacuum chamber 110. In this state, the substrate 210 is heated to a film formation temperature. The film formation temperature is 150°C to 300°C. The inside of the vacuum chamber 110 is then heated to a temperature of 5 to 10×10 by a vacuum pump. -5 The inside of the vacuum chamber 110 is evacuated to a pressure of 100 Pa. This allows the inside of the vacuum chamber 110 to be in a high vacuum environment, making it possible to reduce unintentional reactions of the material being deposited with other substances.

[0045] 5~10×10 -5Ar is introduced into the vacuum chamber 110 at 10 Pa by the gas introduction system 113 so that the Ar partial pressure becomes about 1.0 Pa. In this state, RF is input to the cathode unit 120 by the power supply 130, and a discharge is generated in the vacuum chamber 110. The magnitude of the input RF is 50 W to 200 W when the substrate 210 is located opposite the first target 221. Also, it is 50 W to 200 W when the substrate 210 is located opposite the second target 222. By setting the magnitude of the input RF to a relatively large power while maintaining the ratio between the power during processing of the first target 221 and the power during processing of the second target 222, an oxidation-reduction reaction between the film forming materials can be caused when the first target 221 and the second target 222 collide with each other.

[0046] In the vacuum chamber 110, there are Ar atoms 241 introduced by the gas introduction system 113. Electrons 242 emitted into the vacuum chamber 110 by the discharge collide with the Ar atoms 241, and the Ar + Ions 243 are generated. In other words, Ar becomes plasma. Ar + The ions 243 are incident on the target 220 by the magnetic field generated by the first magnet 121 and the second magnet 122. + Atoms 244 contained in the target 220 are ejected by the ions 243, and collide with and deposit on the substrate 210 facing the target 220. This process is repeated many times to form a film of the light-transmitting magnetic material 1 on the substrate 210. The film formation speed by the film formation apparatus 100 may be quantified in advance, and the film formation time may be set based on the film formation speed so as to obtain a desired film thickness. Thereafter, the film of the light-transmitting magnetic material 1 is annealed at 400° C. to 700° C. for 5 to 120 minutes.

[0047] As described above, the portion of the back plate 231 to which the target 220 is not attached may be covered with a mask 232 .

[0048] As described above, the cathode unit 120 may include a cooling mechanism 123 for circulating cooling water therein. + This reduces the possibility of a temperature rise in the target 220 and the back plate 231 due to the ions 243 being incident on the target 220, and of damage to the target 220 and the back plate 231 due to the temperature rise.

[0049] (Example of manufacturing transparent magnetic material) A manufacturing example of the light-transmitting magnetic material 1 will be described below. As an example of the film-forming apparatus 100, a load-lock type sputtering apparatus CS-200 manufactured by ULVAC was used. As the first target 221, an AlF3 sputtering target manufactured by Kojundo Chemical Laboratory Co., Ltd. was used. As the second target 222, an FeCo sputtering target manufactured by Toshima Manufacturing Co., Ltd. was used.

[0050] Samples were prepared as examples of the present disclosure under the following manufacturing conditions. Example: AlF3 input power 200 W, FeCo input power 50 W, Ar gas pressure 1.0 Pa, film formation temperature 250°C, and rapid cooling after film formation. Here, the AlF3 input power is the RF power input to the first target 221. The FeCo input power is the RF power input to the second target 222. "Quick cooling after film formation" means that the sample manufacturing process includes a process of cooling the substrate after film formation, for example, by opening the chamber after film formation to the atmosphere to perform air cooling.

[0051] Analysis of the state of Fe in this sample revealed that Fe-F in this sample was 34 mol% of the total amount of Fe contained in this sample. An XPS device manufactured by ULVAC-PHI was used for this analysis. Specifically, the surface of the sample was etched to a depth of 100 nm, and then the analysis was performed by irradiating the surface of the sample with AlKα X-rays at a 45° angle.

[0052] (Performance of translucent magnetic materials) The figure of merit indicating the performance of the light-transmitting magnetic material 1 is defined by the following formula (1). Figure of merit = absorption coefficient (dB / μm) / Faraday rotation angle (deg. / μm) (1) In formula (1), the absorption coefficient is a value calculated from the transmittance and reflectance values ​​measured using a Hitachi U-4100 spectrophotometer. The Faraday rotation angle is a value obtained when a magnetic flux is applied to give a magnetic flux density of 1 T using a non-general-purpose Faraday rotation angle measuring device.

[0053] The smaller the absorption coefficient, the smaller the loss of light passing through the light-transmitting magnetic material 1. Also, the larger the Faraday rotation angle, the greater the magneto-optical effect of the light-transmitting magnetic material 1. Therefore, it can be said that the smaller the figure of merit, the higher the performance of the light-transmitting magnetic material 1.

[0054] As a comparative example, a sample was prepared in which the Fe-F value was 27 mol %. The specific manufacturing conditions for the comparative sample are as follows: Comparative example: AlF3 input power 200 W, FeCo input power 50 W, Ar gas pressure 0.4 Pa, film formation temperature 250°C, no rapid cooling after film formation. The figure of merit calculated for the sample of the embodiment was 2.1. Meanwhile, the figure of merit for the sample of the comparative example was 3.1. That is, in the present invention, for example, the performance of the translucent magnetic material 1 can be improved by causing an oxidation-reduction reaction between magnetic particles such as FeCo particles and a translucent material such as a fluoride, and it was found that the sample of the embodiment in which the oxidation-reduction reaction occurs more frequently has improved performance than the sample of the comparative example.

[0055] The manufacturing conditions of the sample of the comparative example are different from those of the sample of the embodiment in that the process of "rapid cooling after film formation" is not included, and the substrate after film formation is removed after the temperature in the chamber is lowered to room temperature after film formation. In general, F chemically bonds more stably with Al than with Fe in a state of thermal equilibrium. In the sample of the comparative example, the state of thermal equilibrium was longer than that of the sample of the embodiment, for example, when waiting for the temperature in the chamber to drop. For this reason, it is presumed that in the sample of the comparative example, the proportion of F in Fe-F that bonds again with Al is larger than that of the sample of the embodiment, and the proportion of Fe-F is smaller.

[0056] Moreover, the manufacturing conditions of the sample of the comparative example are different from those of the sample of the embodiment in that the Ar gas pressure is set to 0.4 Pa. When the Ar gas pressure is high, Al, which has a relatively large particle size in the target, collides with Ar particles more frequently and is less likely to reach the substrate. On the other hand, when the Ar gas pressure is high, the amount of F in AlF that reaches the substrate as a single substance is relatively large, and it is presumed that the oxidation-reduction reaction is more likely to occur. As a result, it is presumed that a higher Ar gas pressure contributes to improving the performance of the light-transmitting magnetic material 1.

[0057] (Simulation of transparent magnetic material) Fig. 4 is a schematic diagram showing an example of a molecular dynamics simulation of the film formation process of the light-transmitting magnetic material 1. In Fig. 4, reference numeral 401 is a schematic diagram in which the light-transmitting material 10 contains AlF3. Reference numeral 402 is a schematic diagram in which the light-transmitting material 10 contains YF3.

[0058] In the diagram of reference numeral 401, region 401a is a region where FeCo particles 20 exist. Moreover, region 401b is a region where light-transmitting material 10 exists. In region 401b, large circles indicate Al atoms, and small circles indicate F atoms. In the simulation shown by reference numeral 401, for example, in region 401c located in the vicinity of region 401b in region 401a, bonding between FeCo particles 20 and F atoms was confirmed.

[0059] In the diagram of reference numeral 402, region 402a is a region where FeCo particles 20 exist. Moreover, region 402b is a region where light-transmitting material 10 exists. In region 402b, large circles indicate Y atoms and small circles indicate F atoms. In the simulation shown by reference numeral 402, for example, in region 402c located in the vicinity of region 402b in region 402a, bonding between FeCo particles 20 and F atoms was confirmed.

[0060] Fig. 5 is a graph showing an example of a simulation result regarding the state of electrons in the light-transmitting magnetic material 1. In Fig. 5, reference numeral 501 is a graph in the case where the light-transmitting material 10 contains AlF3. Reference numeral 502 is a graph in the case where the light-transmitting material 10 contains YF3.

[0061] In the graph of Figure 5, the horizontal axis indicates the energy when the Fermi energy is 0 eV. The graph of the region where the energy is 0 eV or more, i.e., the Fermi energy or more, is meaningless. In the graph of Figure 5, the vertical axis indicates the abundance ratio of electrons.

[0062] In the graph of reference numeral 501, reference numeral 501a indicates the density distribution of electrons in Fe atoms. The peak of reference numeral 501a near -3 eV indicates the density change of the 3d orbital in Fe atoms. From the height of this peak, it can be seen that when the light-transmitting material 10 contains AlF3, Fe bonds with F, and the electron density in Fe atoms increases. At this time, it is considered that an increase in the spin magnetic moment occurs in Al in a metallic state in which AlF3 is reduced, and the magneto-optical effect, i.e., the effect of rotating the polarization plane, increases.

[0063] In the graph of reference numeral 502, reference numeral 502a indicates the density distribution of electrons in Fe atoms. The peak of reference numeral 502a near -4.2 eV indicates the change in the density of electrons in Fe atoms. From the height of this peak, it can be seen that even when the light-transmitting material 10 contains YF3, the density of electrons in Fe atoms increases as Fe bonds with F. At this time, in the metallic state Y in which YF3 is reduced, the orbital magnetic moment and spin magnetic moment increase, and it is considered that the magneto-optical effect, i.e., the effect of rotating the plane of polarization, increases.

[0064] [Embodiment 2] One embodiment of the present disclosure may include an optical element having a light-transmitting magnetic material 1. The optical element may be, for example, a Faraday rotator. As described above, the light-transmitting magnetic material 1 exhibits a high magneto-optical effect compared to conventional materials. Therefore, in a Faraday rotator having the light-transmitting magnetic material 1, the optical path length for rotating the polarization plane by a certain angle can be made shorter than that of a conventional Faraday rotator. Therefore, the Faraday rotator can be made smaller in size.

[0065] The optical element included in one embodiment of the present disclosure is not limited to a Faraday rotator. If the optical element uses a magneto-optical effect, the optical element can be made smaller by including the light-transmitting magnetic material 1.

[0066] In addition, an optical device having an optical element included in one embodiment of the present disclosure is also included in one embodiment of the present disclosure. For example, the optical element included in one embodiment of the present disclosure can be used as a waveguide-type optical isolator by applying the optical element included in one embodiment of the present disclosure to an optical waveguide and allowing the magneto-optical effect to affect the change in the effective refractive index of the optical waveguide. The optical isolator can also be expanded and used as an optical circulator. In addition, the optical element included in one embodiment of the present disclosure can be used in an optical integrated board or an optoelectronic integrated board incorporating an optical isolator and an optical circulator in a circuit, and further in an optical transceiver or a laser light source module with an isolator function incorporating them.

[0067] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure.

[0068] 〔summary〕 The present disclosure can also be expressed as follows.

[0069] The translucent magnetic material according to aspect 1 of the present disclosure comprises a plurality of magnetic particles including a plurality of FeCo particles, and a translucent material having the plurality of magnetic particles dispersed therein, the translucent material having a ceramic material including a compound of at least one element of groups III, IV, and V and fluorine, and a metal material located in a region between the plurality of FeCo particles and the first material.

[0070] A translucent magnetic material according to a second aspect of the present disclosure is based on the first aspect, and the plurality of magnetic particles may have at least one of Fe and Co bonded to a part of a composition constituting the ceramic material.

[0071] In the light-transmitting magnetic material according to a third aspect of the present disclosure, in the first or second aspect, the plurality of magnetic particles may have a redox reaction compound between the FeCo particles and the ceramic material.

[0072] In the light-transmitting magnetic material according to embodiment 4 of the present disclosure, in embodiment 2, 15 mol % or more of the Fe contained in the FeCo particles may be present as Fe—F.

[0073] The light-transmitting magnetic material according to embodiment 5 of the present disclosure may be such that in embodiment 2, 15 mol % or more of the Co contained in the FeCo particles is present as Co-F.

[0074] In the translucent magnetic material according to aspect 6 of the present disclosure, in aspect 3, a portion of the metal material may be in contact with the FeCo particles, and another portion of the metal material may be in contact with a redox reaction compound of the FeCo particles and the first material, the fluoride compound, or the nitride compound.

[0075] In the light-transmitting magnetic material according to a seventh aspect of the present disclosure, in any one of the first to sixth aspects, the metal material may be disposed in the form of a film on the surface of the magnetic particles.

[0076] The translucent magnetic material according to aspect 8 of the present disclosure comprises a translucent material having a first material including a compound of at least one element selected from group III, group IV, and group V and fluorine, and magnetic particles including a plurality of FeCo particles dispersed in the translucent material, the magnetic particles having at least one of Fe and Co bonded to a portion of the composition constituting the ceramic material.

[0077] The optical element according to the ninth embodiment of the present disclosure may have the optically transmissive magnetic material according to any one of the first to eighth embodiments.

[0078] An optical device according to a tenth embodiment of the present disclosure may include the optical element of the ninth embodiment. [Explanation of symbols]

[0079] 1 Translucent magnetic material 10 Translucent material 11 First material 12 Second material 20 FeCo particles

Claims

1. A plurality of magnetic particles including a plurality of FeCo particles; a light-transmitting material having the plurality of magnetic particles dispersed therein; The light-transmitting material includes a ceramic material including a compound of at least one element of group III, group IV, and group V with fluorine, and a metal material located in a region between the plurality of FeCo particles and the ceramic material.

2. The light-transmitting magnetic material according to claim 1 , The plurality of magnetic particles have at least one of Fe and Co bonded to a portion of the composition constituting the ceramic material.

3. The light-transmitting magnetic material according to claim 1 , The plurality of magnetic particles have an oxidation-reduction reaction compound of the FeCo particles and the ceramic material.

4. The light-transmitting magnetic material according to claim 2, A light-transmitting magnetic material, in which 15 mol % or more of the Fe contained in the FeCo particles is present as Fe-F.

5. The light-transmitting magnetic material according to claim 2, A light-transmitting magnetic material, in which 15 mol % or more of Co contained in the FeCo particles exists as Co-F.

6. The light-transmitting magnetic material according to claim 3, a portion of the metallic material is in contact with the FeCo particles; Another portion of the metallic material is in contact with an oxidation-reduction reaction compound of the FeCo particles and the ceramic material.

7. 2. The light-transmitting magnetic material according to claim 1, The metal material is a light-transmitting magnetic material arranged in the form of a film on the surface of the magnetic particles.

8. a transparent material having a ceramic material containing a compound of at least one element of groups III, IV, and V and fluorine; and a magnetic particle including a plurality of FeCo particles dispersed in the light-transmitting material; The magnetic particles have at least one of Fe and Co bonded to a part of the composition constituting the ceramic material.

9. An optical element comprising the light-transmitting magnetic material according to claim 1 or 8.

10. An optical device comprising the optical element according to claim 9.

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