Glass material

Abstract

To provide a glass material exhibiting a high light transmittance and a high Verdet constant in a short wavelength region.SOLUTION: A glass material contains, in mol%, 15 to 50% of CeF3, and 20 to 70% of MgF2+CaF2+SrF2+BaF2+P2O5+SiO2+B2O3+Al2O3.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a glass material suitable as a material for magneto-optical elements constituting magnetic devices such as optical isolators, optical circulators, and magnetic sensors. [Background technology]

[0002] Glass materials containing paramagnetic compounds are known to exhibit the Faraday effect, which is a magneto-optical effect that rotates the plane of polarization of linearly polarized light passing through a material placed in a magnetic field, and is used in optical isolators and magnetic sensors.

[0003] The angle of rotation θ (the angle of rotation of the plane of polarization) due to the Faraday effect is expressed by the following formula (1), where H is the strength of the magnetic field, L is the length of the material through which the polarized light passes, and V is the Verdet constant. The Verdet constant is a constant that depends on the type of material, and is positive for diamagnetic materials and negative for paramagnetic materials. The larger the absolute value of the Verdet constant, the larger the absolute value of the angle of rotation (i.e., the larger the absolute value of the Verdet constant, the greater the Faraday effect).

[0004] θ=VHL ……Formula (1)

[0005] Known examples of glass materials that exhibit the Faraday effect include Tb2O3-based glass materials (Patent Document 1) and P2O5-TbF3-RF2 (R is an alkaline earth metal)-based glass materials (Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2016-145143 A [Patent Document 2] Special Publication No. 55-42942 Summary of the Invention [Problem to be solved by the invention]

[0007] Although the above glass material exhibits high light transmittance in the visible to infrared range, the light transmittance decreases in the short wavelength range of 500 nm or less due to absorption by Tb2O3 and TbF3. Therefore, when a magneto-optical element using the above glass material is used in the above wavelength range, there is a risk of a decrease in light extraction efficiency and damage due to heat generation.

[0008] In view of the above, an object of the present invention is to provide a glass material that exhibits high light transmittance and a high Verdet constant in the short wavelength region. [Means for solving the problem]

[0009] Various aspects of the glass material that solves the above problems will be described below.

[0010] As a result of intensive research, the present inventors have found that the above problems can be solved by a glass material having a specific composition. That is, the glass material of embodiment 1 is characterized by containing, in mole percent, 15-50% of CeF3 and 20-70% of MgF2+CaF2+SrF2+BaF2+P2O5+SiO2+B2O3+Al2O3.

[0011] The glass material of embodiment 2, in accordance with embodiment 1, preferably further contains, in mol %, 20 to 70% of MgF2+CaF2+SrF2+BaF2.

[0012] The glass material of embodiment 3, in embodiment 1 or 2, preferably further contains, in mol %, 0 to 70% of P2O5+SiO2+B2O3+Al2O3.

[0013] The glass material of embodiment 4, in any one of embodiments 1 to 3, preferably further contains, in mol %, 1 to 50% of AlF3.

[0014] The glass material of embodiment 5 is, in terms of cation %, Ce 3+ 15-50%, Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +P5+ +Si 4+ +B 3+ +Al 3+ Contains 20-85% anion, F - 55-100%, O 2- It is characterized by containing 0 to 45%.

[0015] The glass material of embodiment 6 is the same as embodiment 5, further comprising, in cation %, Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ The content is preferably 20 to 80%.

[0016] The glass material of embodiment 7 is the glass material of embodiment 5 or embodiment 6, further comprising, in cation %, P 5+ +Si 4+ +B 3+ +Al 3+ It is preferable that the content is 0 to 80%.

[0017] The glass material of embodiment 8 is any one of embodiments 5 to 7, further comprising, in cation %, Tb 3+ The content is preferably 0 to less than 5%.

[0018] The glass material of embodiment 9, in any one of embodiments 1 to 8, preferably has a light transmittance of 60% or more at a wavelength of 480 nm for a sample thickness of 10 mm.

[0019] The glass material of the tenth embodiment is preferably used as a magneto-optical element in any one of the first to ninth embodiments.

[0020] The glass material of the eleventh embodiment is preferably used as a Faraday element in any one of the first to ninth embodiments. Effect of the Invention

[0021] According to the present invention, it is possible to provide a glass material that exhibits high light transmittance and a high Verdet constant in the short wavelength region. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] (Glass material A) In one embodiment, the glass material of the present invention is characterized by containing, in mole percent, CeF3 15-50% and MgF2+CaF2+SrF2+BaF2+P2O5+SiO2+B2O3+Al2O3 20-70%. The reasons for limiting the composition of glass material A as described above are explained below. In the following explanation of the content of each component of glass material A, % indicates mol % unless otherwise specified.

[0023] CeF3 is an essential component for increasing the absolute value of the Verdet constant and enhancing the Faraday effect. Furthermore, since there is no light absorption peak in the short wavelength region of 500 nm or less (for example, 300 to 400 nm and / or 460 to 500 nm), it is also a component for obtaining a glass material that exhibits high light transmittance in the wavelength region. The content of CeF3 is preferably 15 to 50%. More specifically, the lower limit of the content of CeF3 is preferably 15% or more, 16% or more, 17% or more, 18% or more, 19% or more, and particularly preferably 20% or more. In addition, the upper limit of the content of CeF3 is preferably 50% or less, 49% or less, 48% or less, 47% or less, 46% or less, and particularly preferably 45% or less. If the content of CeF3 is too small, the absolute value of the Verdet constant becomes small, making it difficult to obtain a sufficient Faraday effect. In addition, the light transmittance in the short wavelength region is easily reduced. On the other hand, if the content of CeF3 is too large, it becomes difficult to vitrify. In the following description, the CeF3 content is expressed by converting all of the Ce present in the glass into a trivalent oxide.

[0024] The magnetic moment that gives rise to the Verdet constant is Ce 4+ Ce than 3+ Therefore, the Ce in the glass material 3+ The larger the ratio of Ce, the larger the Faraday effect, which is preferable. 3+ The proportion of Ce in the total Ce is preferably 50% or more, 60% or more, 70% or more, 80% or more, particularly preferably 90% or more, in terms of mole percent. 3+The upper limit of the ratio is not particularly limited, but may be, for example, 100% or less, or 99% or less.

[0025] MgF2, CaF2, SrF2, BaF2, P2O5, SiO2, B2O3 and Al2O3 are components for enhancing the stability of vitrification. The content of MgF2+CaF2+SrF2+BaF2+P2O5+SiO2+B2O3+Al2O3 is preferably 20-70%. More specifically, the lower limit of the content of MgF2+CaF2+SrF2+BaF2+P2O5+SiO2+B2O3+Al2O3 is preferably 20% or more, 21% or more, 25% or more, and particularly preferably 27% or more. In addition, the upper limit of the content of MgF2+CaF2+SrF2+BaF2+P2O5+SiO2+B2O3+Al2O3 is preferably 70% or less, 69% or less, 65% or less, and particularly preferably 64% or less. If the content of MgF2+CaF2+SrF2+BaF2+P2O5+SiO2+B2O3+Al2O3 is too low, the above effects are difficult to obtain. Also, since these components do not contribute to improving the Verdet constant, if the content of MgF2+CaF2+SrF2+BaF2+P2O5+SiO2+B2O3+Al2O3 is too high, it is difficult to obtain a sufficient Faraday effect. Also, the light transmittance in the short wavelength range is likely to decrease. Note that "MgF2+CaF2+SrF2+BaF2+P2O5+SiO2+B2O3+Al2O3" means the total amount of MgF2, CaF2, SrF2, BaF2, P2O5, SiO2, B2O3, and Al2O3. The preferred contents of each of the components MgF2, CaF2, SrF2, BaF2, P2O5, SiO2, B2O3 and Al2O3 are as follows:

[0026] MgF2 is a component that enhances the stability of vitrification. The content of MgF2 is preferably 0 to 70%. More specifically, the lower limit of the content of MgF2 is preferably 0% or more, 1% or more, 2% or more, 5% or more, and particularly preferably 10% or more. From the viewpoint of obtaining a sufficient Faraday effect, the upper limit of the content of MgF2 is preferably 70% or less, 60% or less, 50% or less, 40% or less, and particularly preferably 30% or less.

[0027] CaF2 is a component that enhances the stability of vitrification. The content of CaF2 is preferably 0 to 70%. More specifically, the lower limit of the content of CaF2 is preferably 0% or more, 1% or more, 2% or more, 3% or more, 5% or more, and particularly preferably 10% or more. In order to obtain a sufficient Faraday effect, the upper limit of the content of CaF2 is preferably 70% or less, 60% or less, 50% or less, and particularly preferably 40% or less.

[0028] SrF2 is a component that enhances the stability of vitrification. The content of SrF2 is preferably 0 to 70%. More specifically, the lower limit of the content of SrF2 is preferably 0% or more, 1% or more, 2% or more, 5% or more, and particularly preferably 10% or more. From the viewpoint of obtaining a sufficient Faraday effect, the upper limit of the content of SrF2 is preferably 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, and particularly preferably 20% or less.

[0029] BaF2 is a component that enhances the stability of vitrification. The content of BaF2 is preferably 0 to 70%. More specifically, the lower limit of the content of BaF2 is preferably 0% or more, 1% or more, 2% or more, 5% or more, and particularly preferably 10% or more. From the viewpoint of obtaining a sufficient Faraday effect, the upper limit of the content of BaF2 is preferably 70% or less, 60% or less, 50% or less, 40% or less, and particularly preferably 30% or less.

[0030] P2O5 is a component that enhances the stability of vitrification. It is also a component that easily enhances the water resistance of glass. The content of P2O5 is preferably 0 to 70%. More specifically, the lower limit of the content of P2O5 is preferably 0% or more, 1% or more, 2% or more, and particularly preferably 5% or more. From the viewpoint of obtaining a sufficient Faraday effect, the upper limit of the content of P2O5 is preferably 70% or less, 60% or less, 50% or less, 40% or less, and particularly preferably 30% or less. However, since P2O5 is an oxide, if the content is high, Ce in the glass becomes Ce. 4+This tends to result in a decrease in the Verdet constant and light absorption in the short wavelength region. Therefore, from the viewpoint of increasing the light transmittance particularly in the short wavelength region, the content of P2O5 is preferably 20% or less, 10% or less, 5% or less, and particularly preferably 1% or less.

[0031] SiO2 is a component that enhances the stability of vitrification. It is also a component that easily enhances the water resistance of glass. The content of SiO2 is preferably 0 to 70%. More specifically, the lower limit of the content of SiO2 is preferably 0% or more, 1% or more, 2% or more, and particularly preferably 5% or more. From the viewpoint of obtaining a sufficient Faraday effect, the upper limit of the content of SiO2 is preferably 70% or less, 60% or less, 50% or less, 40% or less, and particularly preferably 30% or less. However, since SiO2 is an oxide, if the content is high, Ce in the glass becomes Ce. 4+ This tends to result in a decrease in the Verdet constant and light absorption in the short wavelength region. Therefore, from the viewpoint of increasing the light transmittance particularly in the short wavelength region, the SiO2 content is preferably 20% or less, 19% or less, 10% or less, and particularly preferably 5% or less.

[0032] B2O3 is a component that enhances the stability of vitrification. It is also a component that easily enhances the water resistance of glass. The content of B2O3 is preferably 0 to 70%. More specifically, the lower limit of the content of B2O3 is preferably 0% or more, 1% or more, 2% or more, and particularly preferably 5% or more. From the viewpoint of obtaining a sufficient Faraday effect, the upper limit of the content of B2O3 is preferably 70% or less, 60% or less, 50% or less, 40% or less, and particularly preferably 30% or less. However, since B2O3 is an oxide, if the content is high, Ce in the glass becomes Ce. 4+ This tends to result in a decrease in the Verdet constant and light absorption in the short wavelength region. Therefore, from the viewpoint of increasing the light transmittance particularly in the short wavelength region, the content of B2O3 is preferably 20% or less, 19% or less, 10% or less, and particularly preferably 5% or less.

[0033] Al2O3 is a component that enhances the stability of vitrification. It is also a component that easily enhances the water resistance of glass. The content of Al2O3 is preferably 0 to 70%. More specifically, the lower limit of the content of Al2O3 is preferably 0% or more, 1% or more, 2% or more, and particularly preferably 5% or more. From the viewpoint of obtaining a sufficient Faraday effect, the upper limit of the content of Al2O3 is preferably 70% or less, 60% or less, 50% or less, 40% or less, and particularly preferably 30% or less. However, since Al2O3 is an oxide, if the content is high, Ce in the glass becomes Ce. 4+ This tends to result in a decrease in the Verdet constant and light absorption in the short wavelength region. Therefore, from the viewpoint of increasing the light transmittance particularly in the short wavelength region, the content of Al2O3 is preferably 20% or less, 10% or less, and particularly preferably 5% or less.

[0034] From the viewpoint of increasing the stability of vitrification and suppressing light absorption in the short wavelength region, the content of MgF2+CaF2+SrF2+BaF2 is preferably 20 to 70%. Since fluorides have a high electronegativity, Ce is preferably added to Ce 3+ It has the effect of keeping it in the glass in a state of being in the above-mentioned state. The lower limit of the content of MgF2+CaF2+SrF2+BaF2 is preferably 20% or more, 25% or more, and particularly 27% or more. In addition, from the viewpoint of obtaining a sufficient Faraday effect, the upper limit of the content of MgF2+CaF2+SrF2+BaF2 is preferably 70% or less, and particularly 60% or less. However, when at least one selected from P2O5, SiO2, B2O3, and Al2O3 is contained from the viewpoint of water resistance, the upper limit of the content of MgF2+CaF2+SrF2+BaF2 may be less than 20%, 10% or less, and particularly 5% or less. Note that "MgF2+CaF2+SrF2+BaF2" means the total amount of MgF2, CaF2, SrF2, and BaF2.

[0035] From the viewpoint of increasing the light transmittance in the short wavelength region and obtaining a sufficient Faraday effect, the content of P2O5+SiO2+B2O3+Al2O3 is preferably 0 to 70%. More specifically, the upper limit of the content of P2O5+SiO2+B2O3+Al2O3 is preferably 70% or less, 65% or less, 60% or less, 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, and particularly preferably 5% or less. In particular, Ce is preferably Ce 3+ From the viewpoint of maintaining the state, it is preferable that P2O5+SiO2+B2O3+Al2O3 is not substantially contained. However, from the viewpoint of water resistance, the lower limit of the content of P2O5+SiO2+B2O3+Al2O3 may be 0% or more, particularly 1% or more. Note that "P2O5+SiO2+B2O3+Al2O3" means the total amount of P2O5, SiO2, B2O3, and Al2O3. In this specification, "substantially not contained" means that it is not intentionally contained in the raw material, and does not exclude the inclusion of impurity levels. Objectively, it means that the content of each component is less than 0.1%.

[0036] The glass material of the present invention may contain the following components.

[0037] AlF3 is a component that forms a glass skeleton and easily expands the vitrification range. The content of AlF3 is preferably 0 to 50%. More specifically, the lower limit of the content of AlF3 is preferably 0% or more, 1% or more, 3% or more, 5% or more, and particularly preferably 10% or more. In order to obtain a sufficient Faraday effect, the upper limit of the content of AlF3 is preferably 50% or less, 40% or less, 38% or less, and particularly preferably 35% or less.

[0038] ZrF4 is a component that easily increases the stability of vitrification. The content of ZrF4 is preferably 0 to 50%. More specifically, the lower limit of the content of ZrF4 is preferably 0% or more, 1% or more, 3% or more, 5% or more, and particularly preferably 10% or more. In order to obtain a sufficient Faraday effect, the upper limit of the content of ZrF4 is preferably 50% or less, and particularly preferably 45% or less.

[0039] From the viewpoint of enhancing the stability of vitrification, NaF, ZnF2, MnF2, or SnF2 may each be contained in an amount of 0% or more, particularly 1% or more. However, since these components do not contribute to the Faraday effect, the content thereof is preferably 20% or less, 15% or less, 10% or less, particularly 9% or less.

[0040] Tb2O3 and TbF3 are components that increase the stability of vitrification and tend to increase the Verdet constant. However, if the content is too high, the light transmittance in the short wavelength region tends to decrease. Therefore, it is preferable that the upper limit of the content of Tb2O3 and TbF3 is less than 5%, 3% or less, and in particular, substantially none is contained.

[0041] From the viewpoint of reducing the impact on the environment, it is preferable that the material does not substantially contain Pb components (PbF2, etc.).

[0042] (Glass material B) In one embodiment of the present invention, the glass material contains, in cation %, Ce 3+ 15-50%, Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +P 5+ +Si 4+ +B 3+ +Al 3+ Contains 20-85% anion, F - 55-100%, O 2- The glass material B is characterized by containing 0 to 45% by weight. The reasons for limiting the composition of the glass material B as described above will be explained below. In the following explanation of the content of each component of the glass material B, % indicates cation % or anion % unless otherwise specified.

[0043] Ce 3+ Ce is an essential component for increasing the absolute value of the Verdet constant and enhancing the Faraday effect. Furthermore, since it has no light absorption peak in the short wavelength region of 500 nm or less (for example, 300 to 400 nm and / or 460 to 500 nm), it is also a component for obtaining a glass material that exhibits high light transmittance in the relevant wavelength region. 3+The content of Ce is preferably 15 to 50%. 3+ The lower limit of the content of Ce is preferably 15% or more, 16% or more, 17% or more, 18% or more, 19% or more, and particularly preferably 20% or more. 3+ The upper limit of the Ce content is preferably 50% or less, 49% or less, 48% or less, 47% or less, 46% or less, and particularly preferably 45% or less. 3+ If the Ce content is too low, the absolute value of the Verdet constant becomes small, making it difficult to obtain a sufficient Faraday effect. Also, the light transmittance in the short wavelength region tends to decrease. 3+ If the content is too high, vitrification becomes difficult.

[0044] In addition, Ce 4+ Ce is also a component that increases the absolute value of the Verdet constant and enhances the Faraday effect. 4+ However, the magnetic moment that is the origin of the Verdet constant is Ce. 4+ By Ce 3+ is larger, so the Ce in the glass material 3+ For example, the cation ratio Ce is preferably large. 3+ / (Ce 3+ +Ce 4+ ) is preferably 0.5 or more, 0.6 or more, 0.7 or more, 0.8 or more, and particularly preferably 0.9 or more. 3+ / (Ce 3+ +Ce 4+ The upper limit of "Ce" is not particularly limited, but may be, for example, 1 or less, particularly 0.99 or less. 3+ / (Ce 3+ +Ce 4+ )" is a Ce 3+ The content of Ce 3+ and Ce 4+ This means the value divided by the total amount of

[0045] Mg 2+ , Ca 2+ , Sr 2+ , B.A. 2+ , P 5+ , Si 4+ , B 3+ and Al 3+is a component that enhances the stability of vitrification. Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ +P 5+ +Si 4+ +B 3+ +Al 3+ The content of Mg is preferably 20 to 85%. 2+ +Ca 2+ +Sr 2+ +Ba 2+ +P 5+ +Si 4+ +B 3+ +Al 3+ The lower limit of the content of Mg is preferably 20% or more, more preferably 21% or more, and particularly preferably 23% or more. 2+ +Ca 2+ +Sr 2+ +Ba 2+ +P 5+ +Si 4+ +B 3+ +Al 3+ The upper limit of the Mg content is preferably 85% or less, more preferably 82% or less, and even more preferably 80% or less. 2+ +Ca 2+ +Sr 2+ +Ba 2+ +P 5+ +Si 4+ +B 3+ +Al 3+ If the content is too low, it is difficult to obtain the above effects. 2+ +Ca 2+ +Sr 2+ +Ba 2+ +P 5+ +Si 4+ +B 3+ +Al 3+ If the content of Mg is too high, it becomes difficult to obtain a sufficient Faraday effect. Also, the light transmittance in the short wavelength region tends to decrease. 2+ +Ca 2+ +Sr 2+ +Ba 2+ +P 5+ +Si 4+ +B 3+ +Al 3+ " is Mg 2+ , Ca 2+ , Sr2+ , B.A. 2+ , P 5+ , Si 4+ , B 3+ and Al 3+ Also, Mg 2+ , Ca 2+ , Sr 2+ , B.A. 2+ , P 5+ , Si 4+ , B 3+ and Al 3+ The preferred contents of the respective components are as follows:

[0046] Mg 2+ is a component that enhances the stability of vitrification. 2+ The content of Mg is preferably 0 to 70%. 2+ The lower limit of the content of Mg is preferably 0% or more, 1% or more, 2% or more, 5% or more, and particularly preferably 10% or more. 2+ The upper limit of the content is preferably 70% or less, 60% or less, 50% or less, 40% or less, and particularly preferably 30% or less.

[0047] Ca 2+ Ca is a component that enhances the stability of vitrification. 2+ The content of Ca is preferably 0 to 70%. 2+ The lower limit of the content of Ca is preferably 0% or more, 1% or more, 2% or more, 3% or more, 5% or more, and particularly preferably 10% or more. 2+ The upper limit of the content is preferably 70% or less, 60% or less, 50% or less, and particularly preferably 40% or less.

[0048] Sr 2+ is a component that enhances the stability of vitrification. 2+ The content of Sr is preferably 0 to 70%. 2+ The lower limit of the content of Sr is preferably 0% or more, 1% or more, 2% or more, 5% or more, and particularly preferably 10% or more. 2+The upper limit of the content is preferably 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, and particularly preferably 20% or less.

[0049] Ba 2+ Ba is a component that enhances the stability of vitrification. 2+ The content of Ba is preferably 0 to 70%. 2+ The lower limit of the Ba content is preferably 0% or more, 1% or more, 2% or more, 5% or more, and particularly preferably 10% or more. 2+ The upper limit of the content is preferably 70% or less, 60% or less, 50% or less, 40% or less, and particularly preferably 30% or less.

[0050] P 5+ is a component that enhances the stability of vitrification. It also tends to increase the water resistance of glass. 5+ The content of P is preferably 0 to 70%. 5+ The lower limit of the content of P is preferably 0% or more, 1% or more, 2% or more, and particularly preferably 5% or more. 5+ The upper limit of the content is preferably 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, and particularly preferably 20% or less.

[0051] S 4+ Si is a component that enhances the stability of vitrification. It also tends to increase the water resistance of glass. 4+ The content of is preferably 0 to 70%. More specifically, Si 4+ The lower limit of the content of Si is preferably 0% or more, 1% or more, 2% or more, particularly preferably 5% or more. 4+ The upper limit of the content is preferably 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, and particularly preferably 20% or less.

[0052] B 3+ is a component that enhances the stability of vitrification. It also tends to increase the water resistance of glass.3+ The content of is preferably 0 to 70%. 3+ The lower limit of the content of B is preferably 0% or more, 1% or more, 2% or more, particularly preferably 5% or more. 3+ The upper limit of the content is preferably 70% or less, 60% or less, 50% or less, 40% or less, and particularly preferably 30% or less.

[0053] Al 3+ Al is a component that easily expands the vitrification range. It also increases the stability of vitrification and increases the water resistance of glass. 3+ The content of Al is preferably 0 to 70%. 3+ The lower limit of the content of Al is preferably 0% or more, 1% or more, 2% or more, and particularly preferably 5% or more. 3+ The upper limit of the content is preferably 70% or less, 60% or less, 50% or less, 40% or less, and particularly preferably 30% or less.

[0054] In order to increase the stability of vitrification and suppress light absorption in the short wavelength region, Mg 2+ +Ca 2+ +Sr 2+ +Ba 2+ The content of Mg is preferably 20 to 70%. 2+ +Ca 2+ +Sr 2+ +Ba 2+ The lower limit of the content of Mg is preferably 20% or more, more preferably 25% or more, and particularly preferably 27% or more. 2+ +Ca 2+ +Sr 2+ +Ba 2+ The upper limit of the content of P is preferably 70% or less, 60% or less, and particularly preferably 55% or less. 5+ , Si 4+ , B 3+ and Al 3+ When at least one selected from the following is contained, Mg 2+ +Ca 2+ +Sr2+ +Ba 2+ The upper limit of the content of Mg may be set to less than 20%, 10% or less, and particularly 5% or less. 2+ +Ca 2+ +Sr 2+ +Ba 2+ " is Mg 2+ , Ca 2+ , Sr 2+ and Ba 2+ This means the total amount of.

[0055] In order to increase the light transmittance in the short wavelength range and obtain a sufficient Faraday effect, 5+ +Si 4+ +B 3+ +Al 3+ The content of P is preferably 0 to 70%. 5+ +Si 4+ +B 3+ +Al 3+ The upper limit of the content of P is preferably 70% or less, 65% or less, 60% or less, 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, and particularly preferably 5% or less. 5+ +Si 4+ +B 3+ +Al 3+ The lower limit of the content of "P" may be set to 0% or more, particularly 1% or more. 5+ +Si 4+ +B 3+ +Al 3+ " is P 5+ , Si 4+ , B 3+ and Al 3+ This means the total amount of.

[0056] F - is an essential component that forms the glass material of the present invention and that easily increases the light transmittance in the short wavelength region. - The content of F is preferably 55 to 100%. - The lower limit of the content of F is preferably 55% or more, 58% or more, 60% or more, 70% or more, 80% or more, 90% or more, and particularly preferably 95% or more. -If the content is too low, it becomes difficult to form glass. In addition, the light transmittance in the short wavelength region tends to decrease. - The upper limit of the content of F is preferably 100% or less. - In order to contain an anion component other than F - The upper limit of the content may be set to 99% or less, 95% or less, and particularly 90% or less.

[0057] The glass material is O 2- However, if the content is too high, the Ce in the glass may become 4+ This leads to a decrease in the Verdet constant and light absorption in the short wavelength region. 2- The upper limit of the content is preferably 45% or less, 40% or less, 30% or less, 20% or less, and particularly preferably 10% or less. 2- The lower limit of the content of O is preferably 0% or more. 2- The lower limit of the content may be 1% or more, particularly 5% or more.

[0058] The glass material of the present invention may contain the following components.

[0059] Zr 4+ Zr is a component that tends to increase the stability of vitrification. 4+ The content of Zr is preferably 0 to 50%. 4+ The lower limit of the content of Zr is preferably 0% or more, 1% or more, 3% or more, 5% or more, and particularly preferably 10% or more. 4+ The upper limit of the content is preferably 50% or less, and particularly preferably 45% or less.

[0060] From the viewpoint of improving the stability of vitrification, Na + , Zn 2+ , Mn 2+ Or Sn 2+may be contained in an amount of 0% or more, particularly 1% or more. However, since these components do not contribute to the Faraday effect, the content thereof is preferably 20% or less, 15% or less, 10% or less, particularly 9% or less.

[0061] Tb 3+ Tb is a component that increases the stability of vitrification and tends to increase the Verdet constant. However, if its content is too high, the light transmittance in the short wavelength region tends to decrease. Therefore, Tb 3+ The upper limit of the content is less than 5%, 3% or less, and it is particularly preferable that the content is substantially zero.

[0062] From the viewpoint of reducing the impact on the environment, it is preferable that the Pb component is substantially not contained.

[0063] The above-mentioned glass materials A and B have the above-mentioned compositions, and therefore exhibit high light transmittance in the short wavelength region (e.g., 300 to 400 nm and / or 460 to 500 nm). For example, the light transmittance at a wavelength of 480 nm with a sample thickness of 10 mm is preferably 60% or more, 65% or more, 70% or more, and particularly 80% or more. The upper limit of the light transmittance is not particularly limited, but may be, for example, 100% or less, and particularly 99% or less. Note that this light transmittance is an external transmittance including reflection.

[0064] The above-mentioned glass materials A and B have the above-mentioned compositions, and therefore exhibit a high Verdet constant in the short wavelength region (e.g., 300 to 400 nm and / or 460 to 500 nm). For example, the Verdet constant at a wavelength of 480 nm is preferably 0.1 min / Oe·cm or more. There is no particular upper limit to the Verdet constant, but it may be, for example, 0.5 min / Oe·cm or less, particularly 0.4 min / Oe·cm or less.

[0065] As described above, the glass material of the present invention exhibits high light transmittance and a high Verdet constant in the short wavelength region, and therefore can be suitably used as a magneto-optical element such as a Faraday element, etc. The magneto-optical element can be suitably used in an optical isolator, an optical circulator, a magnetic sensor, etc. that are used in the short wavelength region. EXAMPLES

[0066] The present invention will be described below based on examples, but the present invention is not limited to these examples.

[0067] Tables 1 to 4 show Examples 1 to 17 of the present invention and Comparative Examples 1 and 2. In addition, Tables 1 and 2 show the components of the Examples and Comparative Examples in terms of mol %, and Tables 3 and 4 show them in terms of cation % and anion %.

[0068] [Table 1]

[0069] [Table 2]

[0070] [Table 3]

[0071] [Table 4]

[0072] The samples were prepared as follows. First, the raw material powders were weighed to obtain the glass composition shown in the table, and mixed thoroughly to prepare a glass raw material. Next, about 100 g of the glass raw material was placed in a platinum crucible and melted at 1000°C to 1300°C in an electric furnace in a nitrogen atmosphere. Finally, the molten glass was poured onto a carbon plate and molded to produce a glass material.

[0073] The Verdet constant at a wavelength of 480 nm and the light transmittance at a wavelength of 480 nm of the obtained glass material were measured.

[0074] The Verdet constant at a wavelength of 480 nm was measured using a Faraday rotation measuring device (manufactured by JASCO Corporation). Specifically, the obtained glass material was first polished to a thickness of 10 mm. Next, the Faraday rotation angle at a wavelength of 480 nm was measured in a magnetic field of 12.5 kOe, and the Verdet constant was calculated.

[0075] The light transmittance at a wavelength of 480 nm was measured using a spectrophotometer (Shimadzu UV-3100). Specifically, the obtained glass material was first polished to a thickness of 10 mm. Next, the transmittance at wavelengths of 300 to 800 nm was measured to obtain a light transmittance curve, and then the light transmittance at 480 nm was read from the light transmittance curve. The light transmittance is an external transmittance including reflection.

[0076] As is clear from Tables 1 to 4, the glass materials of Examples 1 to 17 had a Verdet constant of 0.108 min / Oe cm or more at a wavelength of 480 nm and a high light transmittance of 83.1% or more at a wavelength of 480 nm. On the other hand, the glass materials of Comparative Examples 1 and 2 had a low light transmittance of 49.5% or less at a wavelength of 480 nm. [Industrial Applicability]

[0077] The glass material of the present invention is suitable as a material for magneto-optical elements constituting magnetic devices such as optical isolators, optical circulators, and magnetic sensors.

Claims

1. In mole percent, CeF ３ 15-50%, MgF ２ +CaF ２ + SrF ２ +BaF ２ +P ２ O ５ +SiO ２ +B ２ O ３ +Al ２ O ３ A glass material containing 20 to 70%.

2. Further, in mol%, MgF ２ +CaF ２ + SrF ２ +BaF ２ The glass material according to claim 1, containing 20 to 70%.

3. Further, in mole percent, P ２ O ５ +SiO ２ +B ２ O ３ +Al ２ O ３ The glass material according to claim 1, containing 0 to 70%.

4. Further, in mol%, AlF ３ The glass material according to claim 1 or 2, containing 1 to 50%.

5. Cation %: Ce ３＋ 15-50%, Mg ２＋ +Ca ２＋ + Sr ２＋ +Ba ２＋ +P ５＋ +Si ４＋ +B ３＋ +Al ３＋ Contains 20 to 85% of anion, F － 55-100%, O ２－ A glass material containing 0 to 45%.

6. In addition, the cationic percentage is Mg ２＋ +Ca ２＋ + Sr ２＋ +Ba ２＋ The glass material according to claim 5, containing 20 to 80%.

7. Furthermore, in cationic percentage, P ５＋ +Si ４＋ +B ３＋ +Al ３＋ The glass material according to claim 5, containing 0 to 80%.

8. Furthermore, in cationic percentage, Tb ３＋ The glass material according to claim 5 or 6, containing 0 to less than 5%.

9. 6. The glass material according to claim 1, wherein the glass material has a light transmittance of 60% or more at a wavelength of 480 nm and a sample thickness of 10 mm.

10. The glass material according to claim 1 or 5, which is used as a magneto-optical element.

11. The glass material according to claim 1 or 5, which is used as a Faraday element.

Images