Compound strontium thiostannate and strontium thiostannate infrared optical crystal, preparation method and application thereof

Abstract

This invention provides a compound strontium tin sulfate (Sr2SnS4) and a Sr2SnS4 infrared optical crystal, along with their preparation methods and applications. The compound has the chemical formula Sr2SnS4 and a molecular weight of 422.17. It is a single crystal of Sr2SnS4. The crystal also has the chemical formula Sr2SnS4 and a molecular weight of 422.17. It has two phases, both belonging to the orthorhombic crystal system, with space groups of [missing information]. Pnma (named) α -Sr2SnS4) and Ama 2 (named) β -Sr2SnS4), where, α -Sr2SnS4 cell parameters are a =11.2443(3)Å, b =8.8625(3)Å, c =7.6143(3) Å, unit cell volume is 758.78(4) Å 3 ; β The unit cell parameters of -Sr2SnS4 are a =9.977(1)Å, b =10.311(2)Å, c =7.2432(10) Å, unit cell volume is 745.13 Å 3 It is manufactured using a high-temperature melting spontaneous crystallization method and has potential applications in birefringence and nonlinear optics.

Description

Technical Field

[0001] This invention relates to the compound strontium sulfide and strontium sulfide infrared optical crystals, their preparation methods and applications, and belongs to the field of infrared optoelectronic functional crystal materials. Background Technology

[0002] Infrared crystal applications include birefringent crystals and nonlinear optical crystal materials.

[0003] Nonlinear optical crystal materials can be classified into three main categories based on their transmission wavelength range: 1. Nonlinear optical materials in the ultraviolet and deep ultraviolet bands; 2. Nonlinear optical materials in the visible and near-infrared bands; and 3. Nonlinear optical materials in the infrared and mid-to-far-infrared bands. This invention pertains to nonlinear optical materials in the visible and mid-to-far-infrared bands. Nonlinear optical crystal materials in this band have wide applications, such as in laser frequency converters, infrared lidar, laser communication, infrared filtering devices, and optoelectronic countermeasures.

[0004] To date, the generation of 3-20μm solid-state mid-to-far infrared lasers is mainly based on nonlinear optics principles and infrared nonlinear optical crystal frequency conversion technology. Common infrared nonlinear optical crystals on the market include AgGaS2, AgGaSe2, and CdGeP2. Although these crystals have been used in civilian production, high-tech fields, and military equipment, these crystal materials also have their own shortcomings, and their overall performance still cannot meet ideal requirements. With technological advancements and increasing demands, the need for higher-performance infrared nonlinear crystals is becoming more urgent. Therefore, the exploration of new mid-to-far infrared nonlinear crystals has significant strategic importance for both civilian high-tech industries and the improvement of military equipment. Furthermore, the synthesis and growth of crystal materials represent a significant challenge in this direction.

[0005] Birefringence is the phenomenon where a beam of light incident on a crystal surface produces two refracted beams. The fundamental reason for this phenomenon lies in the optical anisotropy of the crystal material. When light propagates in an optically inhomogeneous body (such as crystals other than cubic systems), except in a few specific directions (along the optical axis), its vibrational characteristics change, decomposing into two polarized beams with mutually perpendicular electric field vector vibrations, different propagation speeds, and unequal refractive indices. This phenomenon is called birefringence, and crystals capable of exhibiting birefringence are called birefringent crystals. The birefringence property of crystals is an important optical performance parameter for optoelectronic functional materials. Utilizing the properties of birefringent crystals, linearly polarized light can be obtained, and beam displacement can be achieved, making birefringent crystals a key material for fabricating optical components such as optical isolators, circulators, beam shifters, optical polarizers, and optical modulators.

[0006] Based on the current development of inorganic birefringent crystal materials, commercially available birefringent materials such as YVO4, CaCO3, LiNbO3, and α-BaB2O4 can almost meet the requirements from the ultraviolet to near-infrared (IR) wavelength range. However, the intrinsic absorption of the MO bond formed by the metal and oxygen limits their application in longer wavelength ranges (>5 μm). Chalcogenides, due to their wide infrared transmission range and coverage of important infrared atmospheric windows, are considered excellent systems for preparing infrared functional materials. Therefore, research on infrared birefringent materials is of great significance. Summary of the Invention

[0007] The purpose of this invention is to provide a compound of strontium tin sulfate (Sr2SnS4) and an infrared optical crystal of Sr2SnS4, as well as their preparation methods and applications. The compound has the chemical formula Sr2SnS4 and a molecular weight of 422.17. It is a single crystal of Sr2SnS4, possessing two phases, both belonging to the orthorhombic crystal system, with space groups Pnma (α-Sr2SnS4) and Ama2 (β-Sr2SnS4), respectively. The crystal also has the chemical formula Sr2SnS4 and a molecular weight of 422.17. It is a single crystal of Sr2SnS4, both belonging to the orthorhombic crystal system, with space groups Pnma (α-Sr2SnS4) and Ama2 (β-Sr2SnS4), respectively. The cell parameters of α-Sr2SnS4 are... The volume of a single cell is The unit cell parameters of β-Sr2SnS4 are The volume of a single cell is It is produced by high-temperature melting and spontaneous crystallization, and its structure is composed of [SnS4] and [SrS7] groups.

[0008] The present invention discloses a compound, strontium tin sulfate (Sr2SnS4), with the chemical formula Sr2SnS4 and a molecular weight of 422.17. This compound is a single crystal of strontium tin sulfate (Sr2SnS4) with two phases, both belonging to the orthorhombic crystal system, with space groups Pnma (α-Sr2SnS4) and Ama2 (β-Sr2SnS4). The cell parameters of α-Sr2SnS4 are as follows: The volume of a single cell is The unit cell parameters of β-Sr2SnS4 are The volume of a single cell is It is made by high-temperature melting of vacuum-sealed quartz tubes.

[0009] A strontium sulfide infrared optical crystal, with the chemical formula Sr₂SnS₄ and a molecular weight of 422.17, is a single crystal of strontium sulfide with two phases, both belonging to the orthorhombic crystal system, with space groups Pnma (named α-Sr₂SnS₄) and Ama² (named β-Sr₂SnS₄), respectively. The cell parameters of α-Sr₂SnS₄ are as follows: The volume of a single cell is The unit cell parameters of β-Sr2SnS4 are The volume of a single cell is

[0010] The aforementioned method for preparing the sulfide-tin-strontium infrared optical crystal employs a vacuum-sealed quartz tube high-temperature melting spontaneous crystallization method, and the specific operation is carried out according to the following steps:

[0011] a. In a glove box filled with nitrogen gas and a sealed container containing 0.1 ppm of both water and oxygen, strontium sulfide, elemental tin, and elemental sulfur are weighed in a molar ratio of 2:1:3, mixed thoroughly, and placed in a clean graphite crucible. The crucible is then placed into a quartz glass tube, and the tube is placed under a vacuum of 10... -5 -10 -3 After vacuuming, the opening is sealed;

[0012] b. Place the sealed quartz tube from step a into a high-temperature furnace and heat it from room temperature to 200°C for 6 hours, then hold it at that temperature for 6 hours; then raise the temperature from 200°C to 810°C for 6 hours, then hold it at that temperature for 60 hours to obtain α-Sr2SnS4; raise the temperature from 200°C to 850°C for 6 hours, then hold it at that temperature for 60 hours to obtain β-Sr2SnS4.

[0013] c. After cooling the α-Sr2SnS4 and β-Sr2SnS4 obtained in step b to room temperature at a rate of 5℃ / h, the samples are removed to obtain α-Sr2SnS4 and β-Sr2SnS4 powdered infrared optical crystal materials.

[0014] The α-Sr2SnS4 and β-Sr2SnS4 infrared optical crystals involved in the strontium sulfide are used in the preparation of infrared band laser modulation crystals, infrared electro-optic devices, infrared communication devices, or infrared laser guidance devices.

[0015] This invention relates to the compounds strontium sulfide (SnS) and SnS infrared optical crystals, their preparation methods, and applications. The crystals have space groups Pnma (α-Sr2SnS4) and Ama2 (β-Sr2SnS4), respectively. In both structures, Sn is tetrahedra, forming [SnS4] tetrahedra, which, together with [SrS7], form a three-dimensional network structure. Both α-Sr2SnS4 and β-Sr2SnS4 crystals exhibit excellent infrared optical properties. α-Sr2SnS4 has a calculated band gap of 3.21 eV based on the HSE06 functional, and a calculated birefringence of 0.123 at 1064 nm. β-Sr2SnS4 crystals possess excellent nonlinear properties; under 1064 nm laser light, its frequency doubling effect is half that of silver gallium sulfide (AgGaS2). First-principles calculations show that β-Sr2SnS4 has an HSE06 band gap of 3.67 eV and a birefringence of 0.064 at 1064 nm, indicating its potential value in birefringence and nonlinear optical applications. Attached Figure Description

[0016] Figure 1 This is a structural diagram of the crystal of α-Sr2SnS4 according to the present invention;

[0017] Figure 2 The powder X-ray diffraction pattern of α-Sr2SnS4 of this invention;

[0018] Figure 3 This is a structural diagram of the crystal of β-Sr2SnS4 according to the present invention;

[0019] Figure 4 The powder X-ray diffraction pattern of β-Sr2SnS4 of the present invention;

[0020] Figure 5 This is a schematic diagram of the working principle of a nonlinear optical system. In the diagram, 1 is a laser, 2 is a convex lens, 3 is a β-Sr2SnS4 crystal, 4 is a prism, and 5 is a filter. The laser beam emitted by the laser 1 passes through the convex lens 2 and enters the β-Sr2SnS4 single crystal 3. The resulting output laser beam passes through the prism 4 and the filter 5 to obtain the desired laser beam. Detailed Implementation

[0021] The present invention will be described in detail through the following embodiments. However, it is not limited to the following embodiments.

[0022] Example 1

[0023] Preparation of the compound strontium sulfide:

[0024] a. In a glove box filled with nitrogen gas and a sealed container containing 0.1 ppm of both water and oxygen, strontium sulfide, elemental tin, and elemental sulfur are weighed in a molar ratio of 2:1:3, mixed thoroughly, and placed in a clean graphite crucible. The crucible is then placed into a quartz glass tube, and the tube is placed under a vacuum of 10... -5 -10 -3 After vacuuming, the opening is sealed;

[0025] b. Place the sealed quartz tube from step a into a high-temperature furnace and heat it from room temperature to 200°C for 6 hours, then hold it at that temperature for 6 hours; then raise the temperature from 200°C to 810°C for 6 hours, then hold it at that temperature for 60 hours to obtain α-Sr2SnS4; raise the temperature from 200°C to 850°C for 6 hours, then hold it at that temperature for 60 hours to obtain β-Sr2SnS4.

[0026] c. After cooling the α-Sr2SnS4 and β-Sr2SnS4 obtained in step b to room temperature at a rate of 5℃ / h, the samples are removed to obtain α-Sr2SnS4 and β-Sr2SnS4 powdered compounds.

[0027] Single-crystal X-ray diffraction analysis revealed that the compound is strontium sulfide (Sr₂SnS₄), with a molecular weight of 422.17. Both belong to the orthorhombic crystal system, with space groups Pnma (named α-Sr₂SnS₄) and Ama₂ (named β-Sr₂SnS₄), respectively. The cell parameters of α-Sr₂SnS₄ are... The volume of a single cell is The unit cell parameters of β-Sr2SnS4 are The volume of a single cell is

[0028] Example 2

[0029] Preparation of strontium-sulfide tin infrared optical crystals according to the reaction formula SrS + SnS + S → Sr2SnS4:

[0030] a. In a glove box filled with nitrogen gas and a sealed container containing 0.1 ppm of both water and oxygen, strontium sulfide, elemental tin, and elemental sulfur are weighed in a molar ratio of 2:1:3, mixed thoroughly, and placed in a clean graphite crucible. The crucible is then placed into a quartz glass tube, and the tube is placed under a vacuum of 10... -5 After vacuuming, the opening is sealed;

[0031] b. Place the sealed quartz tube from step a into a high-temperature furnace and heat it from room temperature to 200°C for 6 hours, then hold it at that temperature for 6 hours; then raise the temperature from 200°C to 810°C for 6 hours, then hold it at that temperature for 60 hours to obtain α-Sr2SnS4; raise the temperature from 200°C to 850°C for 6 hours, then hold it at that temperature for 60 hours to obtain β-Sr2SnS4.

[0032] c. After cooling the α-Sr2SnS4 and β-Sr2SnS4 obtained in step b to room temperature at a rate of 5℃ / h, the samples are removed to obtain α-Sr2SnS4 and β-Sr2SnS4 powdered infrared optical crystal materials.

[0033] Example 3

[0034] Preparation of strontium-sulfide tin infrared optical crystals according to the reaction formula Sr + SnS + S → Sr₂SnS₄:

[0035] a. In a glove box filled with nitrogen gas and containing a sealed container with a water and oxygen content of 0.1 ppm, weigh elemental strontium, tin sulfide, and elemental sulfur in a molar ratio of 2:1:3, mix them thoroughly, place them in a clean graphite crucible, and then place the crucible into a quartz glass tube. Place the quartz tube under a vacuum of 10... -3 After vacuuming, the opening is sealed;

[0036] b. Place the sealed quartz tube from step a into a high-temperature furnace and heat it from room temperature to 200°C for 6 hours, then hold it at that temperature for 6 hours; then raise the temperature from 200°C to 810°C for 6 hours, then hold it at that temperature for 60 hours to obtain α-Sr2SnS4; raise the temperature from 200°C to 850°C for 6 hours, then hold it at that temperature for 60 hours to obtain β-Sr2SnS4.

[0037] c. After cooling the α-Sr2SnS4 and β-Sr2SnS4 obtained in step b to room temperature at a rate of 5℃ / h, the samples are removed to obtain α-Sr2SnS4 and β-Sr2SnS4 powdered infrared optical crystal materials.

[0038] Example 4

[0039] Preparation of strontium sulfide infrared optical crystals according to the reaction formula Sr + Sn + SSR₂SnS₄:

[0040] a. In a glove box filled with nitrogen gas and a sealed container containing 0.1 ppm of both water and oxygen, strontium sulfide, elemental tin, and elemental sulfur are weighed in a molar ratio of 2:1:4, mixed thoroughly, and placed in a clean graphite crucible. The crucible is then placed into a quartz glass tube, and the tube is placed under a vacuum of 10... -5 After vacuuming, the opening is sealed;

[0041] b. Place the sealed quartz tube from step a into a high-temperature furnace and heat it from room temperature to 200°C for 6 hours, then hold it at that temperature for 6 hours; then raise the temperature from 200°C to 810°C for 6 hours, then hold it at that temperature for 60 hours to obtain α-Sr2SnS4; raise the temperature from 200°C to 850°C for 6 hours, then hold it at that temperature for 60 hours to obtain β-Sr2SnS4.

[0042] c. After cooling the α-Sr2SnS4 and β-Sr2SnS4 obtained in step b to room temperature at a rate of 5℃ / h, the samples are removed to obtain α-Sr2SnS4 and β-Sr2SnS4 powdered infrared optical crystal materials.

[0043] Example 5

[0044] Preparation of strontium-sulfide tin infrared optical crystals according to the reaction formula SrS + SnS2 → Sr2SnS4:

[0045] a. In a glove box filled with nitrogen gas (both moisture and oxygen content 0.1 ppm), weigh strontium sulfide and tin sulfide at a molar ratio of 2:1, mix thoroughly, place in a clean graphite crucible, and then place in a quartz glass tube. Place the quartz tube under a vacuum of 10... -3 After vacuuming, the opening is sealed;

[0046] b. Place the sealed quartz tube from step a into a high-temperature furnace and heat it from room temperature to 200°C for 6 hours, then hold it at that temperature for 6 hours; then raise the temperature from 200°C to 810°C for 6 hours, then hold it at that temperature for 60 hours to obtain α-Sr2SnS4; raise the temperature from 200°C to 850°C for 6 hours, then hold it at that temperature for 60 hours to obtain β-Sr2SnS4.

[0047] c. After cooling the α-Sr2SnS4 and β-Sr2SnS4 obtained in step b to room temperature at a rate of 5℃ / h, the samples are removed to obtain α-Sr2SnS4 and β-Sr2SnS4 powdered infrared optical crystal materials.

[0048] Example 6

[0049] Preparation of strontium-sulfide tin infrared optical crystals according to the reaction formula Sr + SnS2 + SSR2SnS4:

[0050] a. Weigh elemental strontium, tin sulfide, and elemental sulfur in a molar ratio of 2:1:2 in a sealed container with a water content and oxygen content of 0.1 ppm.

[0051] b. Mix the elemental strontium, tin sulfide, and elemental sulfur from step a until homogeneous, place the mixture in a clean graphite crucible, then place it into a quartz glass tube, and place the quartz tube under a vacuum of 10... -5 -10 -3 After vacuuming, the opening is sealed;

[0052] c. Place the sealed quartz tube from step b into a high-temperature furnace and heat it from room temperature to 200°C within 6 hours, and hold it at that temperature for 6 hours; for α-Sr2SnS4, heat it from 200°C to 810°C within 6 hours, and for β-Sr2SnS4, heat it from 200°C to 850°C within 6 hours, and hold it at that temperature for 60 hours.

[0053] d. After cooling the new compound from step c to room temperature at a rate of 5℃ / h, the sample is removed to obtain Sr2SnS4 powder crystal material.

[0054] The compound strontium sulfide and strontium sulfide infrared optical crystal, their preparation method, and applications described in this invention are shown in Table 1.

[0055] Table 1 Crystallographic data of Sr2SnS4

[0056]

[0057] As can be seen from the table: the compound has the chemical formula Sr₂SnS₄ and a molecular weight of 422.17. It is a single crystal of strontium tin sulfur. This crystal has two phases, both belonging to the orthorhombic crystal system, with space groups Pnma (named α-Sr₂SnS₄) and Ama₂ (named β-Sr₂SnS₄), respectively. The cell parameters of α-Sr₂SnS₄ are... The volume of a single cell is The unit cell parameters of β-Sr2SnS4 are The volume of a single cell is From F 2 The fitness, final R value, and R value (for all data) indicate that the crystal data analysis is reasonable.

Claims

1. A strontium sulfide infrared optical crystal, characterized in that, The crystal has the chemical formula Sr₂SnS₄ and a molecular weight of 422.

17. It is a single crystal of strontium sulfide, belonging to the orthorhombic crystal system, with space group [missing information]. Pnma Named α -Sr2SnS4, where α The cell parameters of -Sr2SnS4 are: a = 11.2443(3) Å, b = 8.8625(3) Å, c = 7.6143(3) Å, unit cell volume is 758.78(4) Å 3 It is made by high-temperature melting and spontaneous crystallization of vacuum-sealed quartz tubes.

2. A method for preparing a strontium sulfide infrared optical crystal as described in claim 1, characterized in that... The sample was prepared using a vacuum-sealed quartz tube high-temperature melting spontaneous crystallization method, and the specific operation was carried out according to the following steps: a. In a sealed glove box filled with nitrogen gas (both moisture and oxygen content 0.1 ppm), weigh out strontium sulfide, elemental tin, and elemental sulfur in a molar ratio of 2:1:3, mix them thoroughly, place them in a clean graphite crucible, and then place the crucible into a quartz glass tube. Place the quartz tube under a vacuum of 10... -5 -10 -3 After vacuuming, the opening is sealed; b. Place the sealed quartz tube from step a into a high-temperature furnace and heat it from room temperature to 200°C for 6 hours, then hold it at that temperature for 6 hours; then raise the temperature from 200°C to 810°C for 6 hours, and hold it at that temperature for 60 hours to obtain the desired result. α -Sr2SnS4; c. Obtain from step b α -Sr2SnS4 was cooled to room temperature at a rate of 5℃ / h, and the sample was then removed to obtain... α -Sr2SnS4 powdered infrared optical crystal material.

3. The use of the sulfide tin strontium infrared optical crystal as described in claim 1 in the preparation of infrared band laser modulation crystals, infrared electro-optic devices, infrared communication devices, or infrared laser guidance devices.

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