Infrared birefringent optical crystal and preparation method and application thereof

Abstract

The invention discloses an infrared band birefringent crystal with a molecular formula of Ba3CdGe3O2S8 as well as a preparation method and application thereof. The crystal is crystallized in a monoclinic system, the space group is P21 / m, and the cell parameters are as follows: # imgabs0 # # imgabs1 # alpha = 90 degrees, beta = 90.8 + / -0.1 degrees and gamma = 90 degrees. The crystal is prepared by adopting a high-temperature solid-phase method, has the advantages of large birefringence (0.13-0.15), wide infrared transmission range, better crystal growth habit and the like, and has important application value in the high-tech fields of optics, laser lithography, communication and the like; the method is particularly used for manufacturing optical elements such as polarization beam splitting prisms, optical isolators, beam shifters, phase delay devices and electro-optical modulators.

Description

Technical Field

[0001] The invention belongs to the technical field of birefringent optical crystal materials, and relates to an infrared birefringent optical crystal and a preparation method and use thereof, and specifically relates to an infrared band birefringent crystal with a molecular formula of Ba3CdGe3O2S8 and a preparation method and use thereof. Background Art

[0002] Birefringent crystals are a very important type of functional material. They play a vital role in the field of light modulation. They can be used in the preparation of polarizers, optical isolators, ring devices, phase retarders and other devices, and are widely used in many scientific and engineering fields, such as laser technology, polarization measurement and optical communication. At the same time, they are also widely used in laser communication, optical information processing, integrated circuits and military technology. Generally speaking, an ideal birefringent crystal requires that it has the largest possible birefringence and good crystal growth habits in the working band.

[0003] At present, in the ultraviolet and visible light regions, the research on birefringent crystals has made significant progress, and a large number of well-known oxide-based birefringent crystals have been developed, such as TiO2, YVO4, CaCO3, α-BaB2O4 and LiNbO3. However, these birefringent crystals cannot be used in the infrared band due to the infrared absorption caused by the presence of metal-oxygen bonds. Therefore, it is urgent to develop new infrared birefringent crystal materials with large birefringence, wide infrared transmittance range and good crystal growth habits. Summary of the invention

[0004] In order to improve the above technical problems, the present invention provides an infrared band birefringent crystal with a molecular formula of Ba3CdGe3O2S8, a preparation method and use thereof. The optical crystal material has the advantages of a large birefringence index (0.13-0.15), a wide infrared transmittance range and good crystal growth habits.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a compound with the chemical formula of Ba3CdGe3O2S8.

[0007] The present invention also provides a method for preparing the Ba3CdGe3O2S8 compound, which comprises mixing a Ba source, a Cd source, a Ge source and a single substance S, and preparing the Ba3CdGe3O2S8 compound by a high temperature solid phase method.

[0008] According to an embodiment of the present invention, the Ba source is a single substance of Ba or BaO or BaS.

[0009] According to an embodiment of the present invention, the Cd source is Cd element or CdO or CdS.

[0010] According to an embodiment of the present invention, the Ge source is Ge single substance or GeO2 or GeS2.

[0011] According to an embodiment of the present invention, the molar ratio of the Ba source, the Cd source, the Ge source and S is 3:1:3:(2-8).

[0012] According to an embodiment of the present invention, the insulation temperature of the high temperature solid phase method is 700-1200°C, preferably 800-1100°C, and exemplarily is 700°C, 800°C, 900°C, 950°C, 1000°C, 1050°C, 1100°C, 1200°C.

[0013] According to an embodiment of the present invention, the holding time of the high temperature solid phase method is not less than 50 hours, preferably 70 to 150 hours, exemplified by 70 hours, 80 hours, 100 hours, 110 hours, 120 hours, 150 hours, 180 hours, and 200 hours.

[0014] According to an embodiment of the present invention, the high temperature solid phase method specifically comprises: heating the mixed raw materials, maintaining the high temperature, and cooling to room temperature to obtain the Ba3CdGe3O2S8 compound.

[0015] In the present invention, the room temperature refers to a temperature not higher than 100°C, preferably not higher than 50°C.

[0016] Preferably, the high temperature solid phase method is carried out under vacuum conditions. Further preferably, the vacuum pressure is 10 -4 ~10 -3 Pa.

[0017] According to an embodiment of the present invention, the high temperature solid phase reaction is carried out in a sealed container. Preferably, the sealed container has a vacuum environment, for example, the sealed container is a sealed quartz reaction tube.

[0018] Preferably, the cooling includes cooling to 300° C. and then naturally cooling to room temperature. Further preferably, the cooling is performed at a rate of no more than 5° C. / hour.

[0019] Preferably, the preparation method further comprises washing and drying the product obtained by naturally cooling to room temperature to obtain the optical crystal. For example, washing with water (such as deionized water) and drying with ethanol (such as spraying ethanol on the sample surface to accelerate the drying speed of the sample).

[0020] The present invention also provides an optical crystal, the molecular formula of which is Ba3CdGe3O2S8.

[0021] According to an embodiment of the present invention, the structure of the optical crystal belongs to the monoclinic system, the space group is P21 / n, and its unit cell parameters are α=90°,β=90~91°,γ=90°;Exemplarily, its unit cell parameters are α=90°, β=90.8±0.1°, γ=90°.

[0022] According to an embodiment of the present invention, the optical crystal has a one-dimensional chain structure, which is mainly composed of tetrahedral [GeOS3], [GeO2S2] and octahedral [CdOS5] as basic asymmetric units, which are interconnected through common vertices, and the alkaline earth metal element Ba is dispersed and filled in the one-dimensional chain structure as a charge balance.

[0023] According to an embodiment of the present invention, the optical crystal has substantially Figure 1 The crystal structure is shown.

[0024] According to an embodiment of the present invention, the optical crystal has substantially Figure 2 X-ray crystal diffraction pattern shown in a.

[0025] According to an embodiment of the present invention, the optical crystal is an infrared birefringent optical crystal.

[0026] According to the embodiment of the present invention, the optical crystal has the advantages of large birefringence (0.13-0.15), wide infrared transmission range and good crystal growth habit.

[0027] The present invention also provides a method for preparing the above-mentioned Ba3CdGe3O2S8 compound and / or optical crystal, which comprises mixing a Ba source, a Cd source, a Ge source and a single S substance, and preparing the optical crystal by a high-temperature solid phase method.

[0028] According to an embodiment of the present invention, the Ba source is Ba simple substance or BaO or BaS; the Cd source is Cd simple substance or CdO or CdS; the Ge source is Ge simple substance or GeO2 or GeS2.

[0029] According to an embodiment of the present invention, the molar ratio of the Ba source, the Cd source, the Ge source and S is 3:1:3:(2-8).

[0030] According to an embodiment of the present invention, the insulation temperature of the high temperature solid phase method is 700-1200°C, preferably 800-1100°C, and exemplarily is 700°C, 800°C, 900°C, 950°C, 1000°C, 1050°C, 1100°C, 1200°C.

[0031] According to an embodiment of the present invention, the holding time of the high temperature solid phase method is not less than 50 hours, preferably 70 to 150 hours, exemplified by 70 hours, 80 hours, 100 hours, 110 hours, 120 hours, 150 hours, 180 hours, and 200 hours.

[0032] According to an embodiment of the present invention, the high temperature solid phase method specifically comprises: heating the mixed raw materials, maintaining the high temperature, and cooling them to room temperature to obtain the optical crystal.

[0033] In the present invention, the room temperature refers to a temperature not higher than 100°C, preferably not higher than 50°C.

[0034] Preferably, the high temperature solid phase method is carried out under vacuum conditions. Further preferably, the vacuum pressure is 10 -4 ~10 -3 Pa.

[0035] According to an embodiment of the present invention, the high temperature solid phase reaction is carried out in a sealed container. Preferably, the sealed container has a vacuum environment, for example, the sealed container is a sealed quartz reaction tube.

[0036] Preferably, the heating refers to heating to a holding temperature, and the holding temperature of the high temperature solid phase method is 700-1200°C, preferably 800-1100°C, such as 950°C, 1000°C, 1050°C.

[0037] Preferably, the high temperature insulation time is not less than 50 hours, preferably 70 to 150 hours, for example 100 hours, 110 hours, 120 hours.

[0038] Preferably, the cooling includes cooling to 300° C. and then naturally cooling to room temperature. Further preferably, the cooling is performed at a rate of no more than 5° C. / hour.

[0039] Preferably, the preparation method further comprises washing and drying the product obtained by naturally cooling to room temperature to obtain the optical crystal. For example, washing with water (such as deionized water) and drying with ethanol (such as spraying ethanol on the sample surface to accelerate the drying speed of the sample).

[0040] The present invention also provides an infrared birefringent optical crystal, namely the Ba3CdGe3O2S8 optical crystal.

[0041] The present invention also provides the use of the above-mentioned Ba3CdGe3O2S8 compound and / or optical crystal in the manufacture of optical elements such as polarization beam splitter prisms, optical isolators, beam shifters, phase delay devices and electro-optical modulation devices.

[0042] Beneficial effects of the present invention:

[0043] The present invention provides an infrared band birefringent crystal material with a molecular formula of Ba3CdGe3O2S8 and a preparation method thereof, wherein the method comprises mixing a Ba source, a Cd source, a Ge source, and a S single substance, and preparing the optical crystal by a high temperature solid phase method. The crystal material prepared by the method of the present invention has the advantages of a large birefringence index (0.13 to 0.15), a wide infrared transmission range, and a good crystal growth habit.

[0044] The infrared birefringent crystal prepared by the preparation method of the present invention has important application value in high-tech fields such as optics, laser lithography and communication, especially for making optical elements such as polarization beam splitter prisms, optical isolators, beam shifters, phase delay devices and electro-optical modulation devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 This is the crystal structure diagram of Ba3CdGe3O2S8 of the present invention.

[0046] Figure 2 It is the theoretical X-ray diffraction pattern of the Ba3CdGe3O2S8 crystal of the present invention.

[0047] Figure 3 It is a curve diagram of the calculated birefringence of Ba3CdGe3O2S8 crystal of the present invention. DETAILED DESCRIPTION

[0048] The technical scheme of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect.

[0049] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0050] Example 1

[0051] BaS, CdO, Ge and S were mixed in a molar ratio of 3:1:3:5 to obtain raw materials. The raw materials were placed in a quartz crucible, and the quartz crucible containing the raw materials was placed in a quartz reaction tube, and vacuum was drawn to 10 -3 Pa and melt the sealed quartz reaction tube with hydrogen-oxygen flame. Put the quartz reaction tube into a tube furnace with a temperature controller, heat it to 1000℃, and keep it warm for 80 hours. Then cool it to 300℃ at a rate of 5℃ / hour, stop heating, and cool it naturally to room temperature. The product is washed with deionized water and dried with ethanol to obtain the infrared birefringent crystal Ba3CdGe3O2S8, which is recorded as sample 1.

[0052] Example 2

[0053] BaO, CdS, Ge and S were mixed evenly in a molar ratio of 3:1:3:7 to obtain a raw material. The raw material was placed in a quartz crucible, and the quartz crucible containing the raw material was placed in a quartz reaction tube, and vacuum was drawn to 10 -3 Pa and melt the sealed quartz reaction tube with hydrogen-oxygen flame. Put the quartz reaction tube into a tube furnace with a temperature controller, heat it to 950℃, and keep it warm for 100 hours. Then cool it to 300℃ at a rate of 4℃ / hour, stop heating, and cool it naturally to room temperature. The product is washed with deionized water and dried with ethanol to obtain the infrared birefringent crystal Ba3CdGe3O2S8, which is recorded as sample 2.

[0054] Example 3

[0055] BaO, Cd, GeS2 and S were mixed evenly in a molar ratio of 3:1:3:2 to obtain a raw material. The raw material was placed in a quartz crucible, and the quartz crucible containing the raw material was placed in a quartz reaction tube, and vacuum was drawn to 10 -3 Pa and melt the sealed quartz reaction tube with hydrogen-oxygen flame. Place the quartz reaction tube in a tube furnace with a temperature controller, heat it to 850°C, and keep it warm for 120 hours. Then cool it down to 300°C at a rate of 3°C / hour, stop heating, and cool it naturally to room temperature. The product is washed with deionized water and dried with ethanol to obtain the infrared birefringent crystal Ba3CdGe3O2S8, which is recorded as sample 3.

[0056] (1) Structural characterization of samples

[0057] The X-ray single crystal diffraction of the sample in Example 1 was carried out on a Mercury 724 single crystal diffractometer with a Mo target and a K α Radiation source (λ = 0.07107nm), test temperature 293K. And the structure was analyzed by Shelx-2014. The crystallographic data of the sample are shown in Table 1, and the crystal structure diagram is shown in Figure 1 shown.

[0058] Table 1 Crystallographic data of sample Ba3CdGe3O2S8

[0059]

[0060]

[0061] The obtained crystal has a one-dimensional chain structure, which is mainly composed of tetrahedral [GeOS3], [GeO2S2] and octahedral [CdOS5] as basic asymmetric units, which are interconnected through common vertices. The alkaline earth metal element Ba is dispersed and filled in the one-dimensional chain structure as a charge balance.

[0062] (2) Characterization of optical properties of samples

[0063] The optical transmittance range and birefringence values ​​of the samples are shown in Table 2.

[0064] Table 2 Optical performance data of samples

[0065]

[0066] The above is a description of the exemplary embodiments of the present invention. However, the protection scope of the present application is not limited to the above embodiments. Any modification, equivalent substitution, improvement, etc. made by those skilled in the art within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A compound with the chemical formula Ba3CdGe3O2S8.

2. A method for preparing the Ba3CdGe3O2S8 compound according to claim 1, the method comprising mixing a Ba source, a Cd source, a Ge source and a single S substance, and preparing the Ba3CdGe3O2S8 compound by a high temperature solid phase method.

3. The preparation method according to claim 2, characterized in that: The Ba source is Ba element or BaO or BaS. Preferably, the Cd source is Cd element or CdO or CdS. Preferably, the Ge source is Ge element or GeO2 or GeS2. Preferably, the molar ratio of the Ba source, Cd source, Ge source and S is 3:1:3:(2-8).

4. The preparation method according to claim 2, characterized in that: The insulation temperature of the high temperature solid phase method is 700-1200° C., preferably 800-1100° C.; the insulation time of the high temperature solid phase method is not less than 50 hours, preferably 70-150 hours.

5. An optical crystal, characterized in that: The molecular formula of the optical crystal is Ba3CdGe3O2S8.

6. The optical crystal according to claim 5, characterized in that The structure of the optical crystal belongs to the monoclinic system, the space group is P21 / n, and its unit cell parameters are α=90°, β=90~91°, γ=90°. Preferably, the optical crystal has a one-dimensional chain structure, which is mainly composed of tetrahedral [GeOS3], [GeO2S2] and octahedral [CdOS5] as basic asymmetric units, which are interconnected through common vertices, and the alkaline earth metal element Ba is dispersed and filled in the one-dimensional chain structure as a charge balance.

7. The method for preparing an optical crystal according to claim 5 or 6, characterized in that: The preparation method comprises mixing a Ba source, a Cd source, a Ge source and a S single substance, and preparing the optical crystal by a high-temperature solid phase method.

8. The preparation method according to claim 7, characterized in that: The molar ratio of the Ba source, Cd source, Ge source, and S is 3:1:3:(2-8). Preferably, the high temperature solid phase method is carried out under vacuum conditions. Preferably, the vacuum pressure is 10 -4 ~10 -3 Pa. Preferably, the insulation temperature of the high temperature solid phase method is 700-1200°C, preferably 800-1100°C. Preferably, the high temperature insulation time is not less than 50 hours, preferably 70 to 150 hours.

9. An infrared birefringent optical crystal, namely the Ba3CdGe3O2S8 optical crystal as claimed in claim 5 or 6.

10. Use of the Ba3CdGe3O2S8 compound described in claim 1 and / or the optical crystal described in claim 5 or 6 in the manufacture of optical elements such as polarization beam splitters, optical isolators, beam shifters, phase delay devices and electro-optical modulation devices.

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