Translucent magnetic material, optical element and optical device

Abstract

The present invention provides a translucent magnetic material having excellent optical characteristics. The 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.

Description

Light-transmitting magnetic material, optical element, and optical device

[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.

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

[0003] Japanese Patent Publication No. 2021-27222 Japanese Patent Publication No. 2017-98423

[0004] A translucent magnetic material according to one aspect 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, wherein the translucent material has a ceramic material containing a compound of fluorine and at least one element selected from group III, group IV, and group V, and a metal material located in a region between the plurality of FeCo particles and the first material.

[0005] Fig. 1 is a schematic diagram showing an outline of a light-transmitting magnetic material according to one embodiment of the present disclosure; Fig. 2 is a schematic diagram showing an example of the configuration of a film-forming apparatus; Fig. 3 is a schematic diagram showing the operation of a film-forming apparatus; Fig. 4 is a diagram showing an example of a molecular dynamics simulation of a film-forming process of a light-transmitting magnetic material; and Fig. 5 is a graph showing an example of a simulation result of the state of electrons in a light-transmitting magnetic material.

[0006] [Embodiment 1] Hereinafter, one embodiment of the present disclosure will be described in detail. The sizes of components in each drawing do not necessarily correspond to the actual sizes of the components.

[0007] (Structure of Light-Transmitting 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 30% by volume or more and 90% by volume or less. Furthermore, the plurality of magnetic particles 20 may be contained in the light-transmitting magnetic material 1 in a range of 10% by volume or more and 70% by volume or less, for example.

[0008] 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 referred to as granules. The light-transmitting magnetic material 1 in which granules are dispersed in the light-transmitting material 10 may also be referred to as a nanogranular material. The magnetic particles 20 may be magnetic as a whole, and may contain a non-magnetic material as a constituent thereof. For example, atoms of the non-magnetic material may be bonded to dangling bonds on the surface of the magnetic particles 20.

[0009] A part of the magnetic particle 20 may have an oxidized compound, i.e., a compound produced by an oxidation-reduction reaction. That is, some atoms constituting the magnetic particle 20 may be oxidized to lose electrons and undergo a chemical reaction with other atoms to form a compound. For example, when the magnetic particle 20 is an FeCo particle 20, the Fe ２＋ or Co ２＋ In the present disclosure, a compound produced by a redox reaction may be referred to as a redox reaction compound.

[0010] 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. Furthermore, 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 are more likely to retain their magnetism. These average particle diameters can be measured, for example, by calculating the average of multiple particle diameters observed with a TEM (Transmission Electron Microscope).

[0011] The light-transmitting material 10 includes a first material 11 having light-transmitting properties. The first material 11 may be, for example, a ceramic material. The ceramic material may be, for example, an oxide, a fluoride, or a nitride. The ceramic material may be, for example, a material having radical electrons. The ceramic material may be, for example, a semiconductor material.

[0012] In this embodiment, the light-transmitting material 10 may contain a compound of fluorine and at least one element of groups III, IV, and V as the first material 11. Specifically, the first material 11 may be, for example, MgF ２ , AlF ３ , Y.F. ３ , ScF ３ , TiF ４ , ZrF ４ , V.F. ５ and NbF ５ The ceramic material may contain any one of the following materials. The ceramic material may be a single material or a mixture of multiple materials. Specifically, the ceramic material may contain MgF ２ , AlF ３ , Y.F. ３ , ScF ３ , TiF ４ , ZrF ４ , V.F. ５ and NbF ５ The first material 11 may be a mixture of two or more of the above materials. The first material 11 may exist in an amorphous state.

[0013] The first material 11 of the light-transmitting material 10 is arranged so as to be located in the region between each magnetic particle 20. The first material 11 may be filled in the region between each magnetic particle 20 so as to separate or separate the multiple magnetic particles 20 so as not to contact each other. Furthermore, the magnetic particles 20 and the first material 11 may be polarized.

[0014] In this embodiment, the first material 11 is MgF excluding unintentional impurities. ２ , AlF ３ , Y.F. ３ , ScF ３ , TiF ４ , ZrF ４ , V.F. ５ or NbF ５ That is, the first material 11 is mainly composed of MgF ２ , AlF ３ , Y.F. ３ , ScF ３ , TiF ４ , ZrF ４ , V.F. ５ or NbF ５ The first material 11 includes a light-transmitting material such as a material having a translucent property. The main component refers to, for example, a component that serves as the base material of the first material 11. The main component may also refer to, for example, the 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, the component that has the greatest effect on the properties 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 light-transmitting material 10.

[0015] The light-transmitting material 10 has light-transmitting properties due to the first material 11 being the main component. 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. Furthermore, 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 part of the materials constituting the light-transmitting material 10.

[0016] 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 minor component. The second material 12 included in the light-transmitting material 10 may be part of the composition of the first material 11, or may not be part of the composition of the light-transmitting material. The second material 12 may be included in the light-transmitting material 10 in a range of 10 volume % or more and 60 volume % or less of the light-transmitting material 10.

[0017] 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. Furthermore, the second material 12 may exist as a plurality of metal atoms metallically bonded to each other, as metal atoms covalently bonded to atoms constituting the magnetic particle 20, or as simple metal atoms in an ionic state.

[0018] The second material 12 may be arranged in the form of a film on the surface of the magnetic particle 20. Alternatively, the second material 12 may be arranged 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.

[0019] As described above, the magnetic particle 20 may have an oxide compound. A portion 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 near the magnetic particle 20. The magnetic particle 20 may have a compound other than the oxide compound, for example, that is composed of a portion of the composition of the magnetic particle 20 and a portion of the composition of the first material 11. Specifically, if the first material 11 is a fluoride, the oxide compound may be a fluoride different from the first material 11. Furthermore, if the first material 11 is a nitride, the oxide compound may be a nitride different from the first material. Furthermore, if the first material 11 is an oxide, the oxide compound may be an oxide different from the first material.

[0020] In this embodiment, the main component of the first material 11 is MgF ２ , AlF ３ , Y.F. ３ , ScF ３ , TiF ４ , ZrF ４ , V.F. ５ or NbF ５ Therefore, the magnetic particles 20 are MgF ２ , AlF ３ , Y.F. ３ , ScF ３ , TiF ４ , ZrF ４ , V.F. ５ or NbF ５ The magnetic particles 20 may undergo an oxidation-reduction reaction with FeF and CoF, and may have Fe—F and Co—F. That is, the magnetic particles 20 may have at least one of Fe and Co bonded to a part of the composition of the first material 11. The Fe—F includes FeF, FeF ２ and FeF ３ Co—F may be present in at least one form of CoF ２ It may be present in the form:

[0021] A portion of the second material 12 may be in contact with the magnetic particles 20. Another portion of the second material 12 may be in contact with an oxide compound of the magnetic particles 20 or other compounds.

[0022] The oxide compound of the magnetic particle 20 may cover the surface of the main body of the magnetic particle 20 in the form of a film so as to constitute the surface layer of the magnetic particle 20, or may be arranged in a speckled pattern on the surface of the main body so as to constitute 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 a 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 minor component. As shown in FIG. 1 , the third material 13 may be arranged around the magnetic particle 20 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. Furthermore, the oxide compound that forms 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 in the light-transmitting material 10 may be the same as that of the second material 12, for example.

[0023] Alternatively, a portion of the second material 12 may be generated by reducing the magnetic particles 20. In this case, the reduced material is located on the surface of the magnetic particles 20 and in the vicinity thereof. In this embodiment, the first material 11 is MgF ２ In the case where the first material 11 contains AlF, the reduced product contains Mg (magnesium). ３ In the case where the first material 11 contains YF, the reduced product contains Al (aluminum). ３ In the case where the first material 11 contains ScF, the reduced product contains Y (yttrium). ３ In the case where the first material 11 contains TiF, the reduced product contains Sc (scandium). ４ In the case where the first material 11 contains ZrF, the reduced product contains Ti (titanium). ４ In the case where the first material 11 contains VF, the reduced product contains Zr (zirconium). ５ When the first material 11 contains NbF, the reduced product contains V (vanadium). ５In the case where the magnetic particle 20 contains the second material 12, the reduced material contains Nb (niobium). In this case, the reduced material 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. The reduced material may also be the second material 12 contained in the light-transmitting material 10.

[0024] In such a light-transmitting magnetic material 1, the presence of oxide compounds of the magnetic particles 20, such as Fe—F and Co—F, increases the density of the outermost electrons of Fe, Co, and F. Furthermore, the magnetic moment increases 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 of rotating the polarization plane of light incident on the light-transmitting magnetic material 1, particularly the second material 12, is enhanced. Therefore, the light-transmitting magnetic material 1 containing the second material 12 has excellent optical properties.

[0025] The magnetic moment is expressed as the sum of the orbital magnetic moment and the spin magnetic moment. Therefore, to obtain a translucent 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 electrons donated during a reduction reaction. In particular, the metal fluoride contained in the first material 11 may be a metal fluoride in which electrons donated during a reduction reaction enter an orbital with a higher orbital magnetic moment. For example, the metal fluoride contained in the first material 11 may be a metal fluoride in which electrons donated during a reduction reaction enter a d orbital, and may be a compound of at least one element of Group IV and Group V with fluorine. In another example, the metal fluoride contained in the first material 11 may be a material in which electrons donated during a reduction reaction enter a d orbital but which do not have electrons in a d orbital before reduction, specifically, YF ３ , ScF ３ , TiF ４ , ZrF ４ , V.F. ５ or NbF ５ It may be.

[0026] 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 abundance ratio of the oxide compound can be measured, for example, by XPS (X-ray photoelectron spectroscopy) or the like.

[0027] (Method of Manufacturing Light-Transmitting Magnetic Material) The light-transmitting magnetic material 1 may be manufactured by, for example, sputtering film formation. An example of a method of manufacturing the light-transmitting magnetic material 1 will be described below.

[0028] FIG. 2 is a schematic diagram showing an example of the configuration of a film formation apparatus 100. The film formation apparatus 100 may be an apparatus that forms a film of the light-transmitting magnetic material 1 by sputtering. As shown in FIG. 2, the film formation apparatus 100 may include a vacuum chamber 110, a cathode unit 120, and a power supply 130. The film formation apparatus 100 is an apparatus that deposits atoms contained in a target 220 onto a substrate 210 by sputtering. There are no particular restrictions on the material of the substrate 210, as long as it is not highly reactive with the atoms deposited by sputtering. The material of the target 220 will be described later.

[0029] The vacuum chamber 110 may be a chamber that can be made into a vacuum state inside. The vacuum chamber 110 may be made of a conductor. The vacuum chamber 110 may also be grounded.

[0030] The vacuum chamber 110 may have an opening 111. The cathode unit 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 unit 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.

[0031] The vacuum chamber 110 may further include a gas introduction system 113. The gas introduction system 113 introduces gas at a constant flow rate into the vacuum chamber 110, which is in a vacuum state, to create an atmosphere at a constant pressure corresponding 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.

[0032] 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. With the cathode portion 120 fitted into the opening 111, the substrate holder 115 and the cathode portion 120 may face each other.

[0033] The substrate holder 115 may be equipped with a heater (not shown). By heating the substrate 210 with the heater during film formation, it is possible to control the temperature during film formation of the light-transmitting magnetic material 1. Furthermore, by heating the substrate 210 on which the light-transmitting magnetic material 1 has been formed after film formation, it is possible to improve the crystallinity of the light-transmitting magnetic material 1.

[0034] 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 copper, for example. The back plate 231 may be disposed on the cathode section 120, thereby disposing the target 220 on the cathode section 120.

[0035] The cathode unit 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 hollow and cylindrical and surrounding the first magnet 121. The first magnet 121 and the second magnet 122 may be arranged such that, when the target 220 is placed on the cathode unit 120, their magnetic poles facing the target 220 are opposite to each other. For example, as shown in FIG. 2 , the north pole of the first magnet 121 may face the target 220. Furthermore, the south pole of the second magnet 122 may face the target 220.

[0036] The cathode unit 120 may further include a cooling mechanism 123 that circulates cooling water therein 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.

[0037] The power supply 130 may be a power supply that inputs RF (Radio Frequency) power to the cathode unit 120. The power supply 130 may input, for example, 13.56 MHz power. As described above, the vacuum chamber 110 is grounded. Therefore, when RF is input to the cathode unit 120 while the inside of the vacuum chamber 110 is in a vacuum state, a discharge occurs inside the vacuum chamber 110. A matching box 131 that matches the impedance between the power supply 130 and the cathode unit 120 may be arranged between the power supply 130 and the cathode unit 120.

[0038] 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 from FIG. 3. In the film formation apparatus 100, the substrate holder 115 may be rotatable around a rotation axis perpendicular to the surface on which the substrate 210 is disposed. Alternatively, 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.

[0039] In the film forming apparatus 100, the cathode section 120 may be provided with a first target 221 and a second target 222 as the targets 220. The first target 221 is AlF ３ , Y.F. ３ , or MgF ２ The second target 222 may include FeCo.

[0040] The substrate 210 may be displaced between a position facing the first target 221 and a position facing the second target 222 by rotating the substrate holder 115. By forming a film while displacing the substrate 210 between a position facing the first target 221 and a position facing the second target 222, AlF ３ , Y.F.３ , or MgF ２ A film of a light-transmitting magnetic material 1 is formed, which is a mixture of FeCo and Fe.

[0041] 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 able to move back and forth between a position facing the first target 221 and a position facing the second target 222. In this case, too, film formation can be performed while the substrate 210 is displaced between the position facing the first target 221 and the position facing the second target 222.

[0042] The power supply 130 may input different amounts of power to the cathode unit 120 depending on whether the substrate 210 is positioned facing the first target 221 or 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.

[0043] A specific example of a film formation method using the film formation apparatus 100 is shown below. The numerical values ​​in the specific example are merely examples and do 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 inserted 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. Furthermore, the inside of the vacuum chamber 110 is heated by a vacuum pump to a temperature of 5 to 10 x 10 －５ The inside of the vacuum chamber 110 is evacuated to a pressure of Pa. This allows the inside of the vacuum chamber 110 to be in a high vacuum environment, and makes it possible to reduce the possibility of the material being deposited reacting unintentionally with other substances.

[0044] 5 to 10 x 10 －５Ar is introduced into the vacuum chamber 110 at 100 Pa via the gas introduction system 113 so that the Ar partial pressure is approximately 1.0 Pa. In this state, RF is input to the cathode 120 by the power supply 130, generating a discharge within the vacuum chamber 110. The magnitude of the input RF is 50 W to 200 W both when the substrate 210 is positioned facing the first target 221 and when the substrate 210 is positioned facing the second target 222. While maintaining the ratio of the power during processing of the first target 221 to the power during processing of the second target 222 at a ratio corresponding to the ratio of the film formation rates, the magnitude of the input RF is set to a relatively large power within the above range. This allows a redox reaction to occur between the film formation materials when the film formation materials from the first target 221 and the second target 222 collide on the substrate 210.

[0045] Ar atoms 241 introduced by a gas introduction system 113 are present in the vacuum chamber 110. Electrons 242 emitted into the vacuum chamber 110 by the discharge collide with the Ar atoms 241, and the Ar atoms ＋ Ions 243 are generated. That is, Ar becomes plasma. ＋ 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, which collide with and deposit on the substrate 210 facing the target 220. This process is repeated many times, thereby forming a film of the light-transmitting magnetic material 1 on the substrate 210. The film formation rate by the film formation apparatus 100 may be quantified in advance, and the film formation time may be set based on this film formation rate to achieve the desired film thickness. The film of the light-transmitting magnetic material 1 is then annealed at 400°C to 700°C for 5 to 120 minutes.

[0046] As described above, the area of ​​the back plate 231 where the target 220 is not attached may be covered with a mask 232 .

[0047] As described above, the cathode section 120 may include a cooling mechanism 123 that circulates cooling water inside. ＋ 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.

[0048] (Manufacturing Example of Light-Transmitting 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 sputtering apparatus CS-200 manufactured by ULVAC was used. As the first target 221, AlF ３ As the second target 222, a FeCo sputtering target manufactured by Toshima Manufacturing Co., Ltd. was used.

[0049] Samples were prepared as examples of the present disclosure. The manufacturing conditions for the samples of the examples are as follows: Example: AlF ３ The input power was 200 W, the FeCo input power was 50 W, the Ar gas pressure was 1.0 Pa, the film formation temperature was 250°C, and the film was rapidly cooled after formation. ３ The 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 to the atmosphere after film formation to perform air cooling.

[0050] Analysis of the state of Fe in this sample revealed that the Fe-F content in this sample was 34 mol% of the total amount of Fe contained in this sample. An XPS device manufactured by ULVAC-PHI, Inc. was used for this analysis. Specifically, the surface of the sample was etched to a depth of 100 nm, and then AlKα rays were irradiated onto the surface of the sample at a 45° angle for analysis.

[0051] (Performance of Light-Transmitting Magnetic Material) A figure of merit indicating the performance of the light-transmitting magnetic material 1 was 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 measured when a magnetic flux is applied so that the magnetic flux density becomes 1 T using a non-general-purpose Faraday rotation angle measuring device.

[0052] The smaller the absorption coefficient, the smaller the loss of light passing through the light-transmitting magnetic material 1. Furthermore, 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.

[0053] As a comparative example, a sample was prepared in which the Fe—F value in the sample was 27 mol %. The specific manufacturing conditions for the comparative sample were as follows: Comparative example: AlF ３ The input power was 200 W, the FeCo input power was 50 W, the Ar gas pressure was 0.4 Pa, the film formation temperature was 250°C, and no rapid cooling was performed after film formation. The figure of merit calculated for the sample of the example was 2.1. On the other hand, the figure of merit for the sample of the comparative example was 3.1. That is, in the present disclosure, 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 fluoride. In particular, it was found that the sample of the example, in which a greater amount of oxidation-reduction reaction occurred, had improved performance compared to the sample of the comparative example.

[0054] The manufacturing conditions for the sample of the comparative example differ from those for the sample of the example 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 has dropped to room temperature. Generally, F chemically bonds more stably with Al than Fe in a state of thermal equilibrium. The sample of the comparative example remained in a state of thermal equilibrium for a longer period than the sample of the example, for example, when waiting for the temperature in the chamber to drop. Therefore, it is presumed that the proportion of F in Fe-F that recombines with Al is greater in the sample of the comparative example than in the sample of the example, resulting in a smaller proportion of Fe-F.

[0055] Furthermore, the manufacturing conditions for the sample of the comparative example differ from those for the sample of the example 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, frequently collides with Ar particles, making it difficult for it to reach the substrate. On the other hand, when the Ar gas pressure is high, it is presumed that the amount of F in AlF that reaches the substrate as a single element increases, making it easier for an oxidation-reduction reaction 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.

[0056] (Simulation of Light-Transmitting 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 denotes a simulation in which the light-transmitting material 10 is AlF ３ The reference numeral 402 denotes a schematic diagram in which the light-transmitting material 10 contains YF. ３ FIG.

[0057] In the diagram indicated by the reference numeral 401, a region 401a is a region where the FeCo particles 20 exist. Furthermore, a region 401b is a region where the light-transmitting material 10 exists. In the region 401b, large circles represent Al atoms, and small circles represent F atoms. In the simulation indicated by the reference numeral 401, for example, in a region 401c located in the region 401a near the region 401b, bonding between the FeCo particles 20 and the F atoms was confirmed.

[0058] In the diagram indicated by the reference numeral 402, a region 402a is a region where the FeCo particles 20 exist. Furthermore, a region 402b is a region where the light-transmitting material 10 exists. In the region 402b, the large circle represents a Y atom, and the small circle represents an F atom. In the simulation indicated by the reference numeral 402, for example, in a region 402c located in the region 402a near the region 402b, bonding between the FeCo particles 20 and the F atoms was confirmed.

[0059] 5 is a graph showing an example of a simulation result of the state of electrons in the light-transmitting magnetic material 1. In FIG. 5, reference numeral 501 indicates a state in which the light-transmitting material 10 is AlF ３The graph 502 shows the results when the light-transmitting material 10 contains YF. ３ This is a graph when

[0060] In the graph of Figure 5, the horizontal axis represents energy when the Fermi energy is 0 eV. The graph in the energy region above 0 eV, i.e., above the Fermi energy, is meaningless. Also, in the graph of Figure 5, the vertical axis represents the electron abundance ratio.

[0061] In the graph of reference numeral 501, reference numeral 501a indicates the electron density distribution 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 the light-transmitting material 10 is AlF ３ When the Fe atom contains AlF, the Fe atom bonds with F, increasing the electron density in the Fe atom. ３ It is believed that in the metallic state of Al where Al is reduced, the spin magnetic moment increases, and the magneto-optical effect, that is, the effect of rotating the plane of polarized light, increases.

[0062] In the graph of reference numeral 502, reference numeral 502a indicates the electron density distribution in Fe atoms. The peak of reference numeral 502a near −4.2 eV indicates the change in electron density in Fe atoms. From the height of this peak, it can be seen that the light-transmitting material 10 is YF ３ Even when YF is included, it can be seen that the electron density in the Fe atom increases when Fe bonds with F. ３ In the metallic state of Y where Y is reduced, the orbital magnetic moment and spin magnetic moment increase, and it is thought that the magneto-optical effect, that is, the effect of rotating the plane of polarized light, increases.

[0063] [Embodiment 2] One aspect 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 higher magneto-optical effect than 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 in conventional Faraday rotators. Therefore, the Faraday rotator can be made smaller.

[0064] The optical element included in one aspect of the present disclosure is not limited to a Faraday rotator. If the optical element utilizes a magneto-optical effect, the optical element can be made smaller by including the light-transmitting magnetic material 1.

[0065] Another aspect of the present disclosure also includes an optical device having an optical element according to one aspect of the present disclosure. For example, by applying an optical element according to one aspect of the present disclosure to an optical waveguide and using the magneto-optical effect to change the effective refractive index of the optical waveguide, the optical element can be used as a waveguide-type optical isolator. The optical isolator can also be expanded and used as an optical circulator. Furthermore, the optical element according to one aspect of the present disclosure can be used in an optical integrated circuit board or an optoelectronic integrated circuit board incorporating an optical isolator or an optical circulator into a circuit, as well as in an optical transceiver or a laser light source module with an isolator function incorporating them.

[0066] 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.

[0067] [Summary] The present disclosure can also be expressed as follows.

[0068] A translucent magnetic material according to a first aspect 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, wherein the translucent material has a ceramic material containing a compound of fluorine and at least one element selected from group III, group IV, and group V, and a metal material located in a region between the plurality of FeCo particles and the first material.

[0069] A translucent magnetic material according to a second aspect of the present disclosure is the same as that of the first aspect, wherein the plurality of magnetic particles may have at least one of Fe and Co bonded to a part of the composition constituting the ceramic material.

[0070] In the light-transmitting magnetic material according to Aspect 3 of the present disclosure, in Aspect 1 or 2, the plurality of magnetic particles may have a redox reaction compound of the FeCo particles and the ceramic material.

[0071] The light-transmitting magnetic material according to Aspect 4 of the present disclosure is the same as Aspect 2, wherein 15 mol % or more of the Fe contained in the FeCo particles may be present as Fe—F.

[0072] A light-transmitting magnetic material according to a fifth aspect of the present disclosure is the same as that of the second aspect, wherein 15 mol % or more of the Co contained in the FeCo particles is present as Co—F.

[0073] A translucent magnetic material according to aspect 6 of the present disclosure may be the same as that of aspect 3, wherein a portion of the metal material is in contact with the FeCo particles, and another portion of the metal material is in contact with a redox reaction compound of the FeCo particles and the first material, the fluoride compound, or the nitride compound.

[0074] A seventh aspect of the present disclosure provides a translucent magnetic material according to any one of the first to sixth aspects, wherein the metal material is disposed in the form of a film on the surface of the magnetic particles.

[0075] A translucent magnetic material according to an eighth aspect of the present disclosure comprises a translucent material having a first material containing a compound of fluorine and at least one element selected from group III, group IV, and group V, and magnetic particles including a plurality of FeCo particles dispersed in the translucent material, wherein the magnetic particles have at least one of Fe and Co bonded to a portion of the composition constituting the ceramic material.

[0076] An optical element according to a ninth aspect of the present disclosure may include the optically transmissive magnetic material according to any one of the first to eighth aspects.

[0077] An optical device according to aspect 10 of the present disclosure may include the optical element of aspect 9.

[0078] 1 Transparent magnetic material 10 Transparent material 11 First material 12 Second material 20 FeCo particles

Claims

1. A translucent magnetic material comprising: 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 containing 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 ceramic material.

2. A light-transmitting magnetic material according to claim 1, wherein 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. A light-transmitting magnetic material according to claim 1 or 2, wherein the plurality of magnetic particles have an oxidation-reduction reaction compound between the FeCo particles and the ceramic material.

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

6. A translucent magnetic material according to claim 3, wherein a portion of the metal material is in contact with the FeCo particles, and another portion of the metal material is in contact with an oxidation-reduction reaction compound of the FeCo particles and the ceramic material.

7. A light-transmitting magnetic material according to any one of claims 1 to 6, wherein the metal material is arranged in the form of a film on the surface of the magnetic particles.

8. A translucent magnetic material comprising: a ceramic material containing a compound of at least one element of groups III, IV, and V with fluorine; and magnetic particles containing a plurality of FeCo particles dispersed in the translucent material, wherein the magnetic particles have at least one of Fe and Co bonded to a portion of the composition constituting the ceramic material.

9. An optical element comprising the light-transmitting magnetic material according to any one of claims 1 to 8.

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

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