Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass and preparation method thereof

Abstract

A Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass and its preparation method are disclosed. The composition, expressed as a mass percentage, is: Sn: 15%-35%, Se: 40%-60%, Sb: 5%-20%, Bi: 0.1%-12%, CsCl: 3%-8%, with the sum of the mass percentages of each component being 100%. This invention relates to the technical field of infrared optical materials. By precisely designing the Sn-Se-Sb-Bi composition, this invention obtains a base glass with optimal physical properties within the system, exhibiting an infrared cutoff wavelength of up to 20 μm and an average transmittance of over 65%, providing a high-performance matrix for subsequent reinforcement. Simultaneously, 3-8% by mass of CsCl is innovatively introduced as a nucleating agent, successfully inducing the formation of uniformly distributed CsCl nanocrystals through controllable heat treatment. These nanocrystals, acting as an effective reinforcing phase, significantly improve the material's hardness and toughness (>30%), substantially mitigating the shortcomings of chalcogenide glasses, such as high brittleness, low hardness, and susceptibility to damage.

Description

Technical Field

[0001] This invention relates to the technical field of infrared optical materials, specifically to a Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass and its preparation method. Background Technology

[0002] Chalcogenide glasses, a class of amorphous optical materials composed of chalcogen elements (S, Se, Te), have important applications in civilian and defense fields such as thermal imaging and infrared sensing due to their excellent transmittance, high refractive index, and tunable optical constants in the infrared band (especially the 3-5μm and 8-14μm atmospheric windows). However, their further large-scale commercial application is severely constrained by inherent defects. First, insufficient mechanical properties are a common shortcoming of chalcogenide glasses. Compared with oxide glasses or single-crystal materials, their Vickers hardness is usually lower (generally below 2.0 GPa), and their wear resistance and fracture toughness are poor, making optical components prone to scratches or cracks during processing, assembly, and use, and limiting their environmental adaptability. Second, high production costs are a bottleneck. High-performance chalcogenide glasses usually rely on expensive elements such as germanium (Ge) and gallium (Ga) as network formers or intermediates, and the complex melting and purification processes further increase manufacturing costs. In addition, the subsequent microcrystallization treatment used to achieve mechanical enhancement often has a narrow process window and poor controllability, increasing production difficulty and uncertainty. Finally, environmental requirements are becoming increasingly stringent. Many high-performance chalcogenide glass formulations contain toxic arsenic (As), posing environmental and health risks in production, use, and waste disposal, which is inconsistent with the trend of green manufacturing. Therefore, developing a new type of high-performance chalcogenide glass material that combines high hardness, low cost, and environmental friendliness has become an urgent technological need in this field.

[0003] To address the aforementioned challenges, this invention abandons the traditional technical route that relies on expensive Ge and Ga elements and toxic As elements, and instead constructs a quaternary basic glass system with Sn-Se-Sb-Bi as its core. The considerations for this component design are as follows: First, Sn and Se, as basic network formants, have significantly lower raw material costs than Ge and can form a stable infrared-transmitting matrix; Sb, as a classic network intermediate, can effectively improve glass-forming ability and adjust optical properties. Simultaneously, based on the excellent Sn-Se-Sb component, Bi is innovatively introduced as the fourth component, with three objectives: First, Bi can partially substitute Sb using its chemical similarity, further reducing the phonon energy of the glass network through its heavier atomic mass, providing the possibility of extending long-wave infrared performance; second, the high polarizability of Bi³⁺ helps to enhance the material's nonlinear optical potential; third, Sn, Se, Sb, and Bi are all cost-effective and environmentally friendly elements, fundamentally ensuring the material's low cost and environmentally friendly properties.

[0004] Microcrystallization, which introduces a high-strength crystalline phase into the glass matrix, is an effective way to improve the hardness of chalcogenide glasses. The key challenge lies in selecting a suitable nucleating agent and controlling the crystallization process to minimize optical losses caused by crystal scattering, especially its impact on transmittance in the working wavelength range, while achieving significant hardness enhancement. CsCl, a common halide, has a certain solubility in chalcogenide glasses, and the difference in refractive index between its precipitated crystals and the chalcogenide matrix in the infrared band is relatively controllable, making it a potentially preferred nucleating agent. However, there are currently no reports on the introduction of CsCl into the Sn-Se-Sb-Bi system and a systematic study on its synergistic effect on the wide infrared window characteristics and mechanical properties of the material. Summary of the Invention

[0005] The purpose of this invention is to provide a Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass and its preparation method, overcoming the shortcomings of insufficient hardness in existing chalcogenide glasses, and providing an environmentally friendly chalcogenide microcrystalline glass and its preparation method that has both high transparency and high hardness in the long-wave infrared band (8-14μm).

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: a Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass, the composition of which is expressed in mass percentage as follows: Sn: 15%-35%, Se: 40%-60%, Sb: 5%-20%, Bi: 0.1%-12%, CsCl: 3%-8%, and the sum of the mass percentages of the above components is 100%.

[0007] The composition must satisfy the calculated average coordination number MCN = 2.4. This condition is achieved by optimizing the ratio of network-forming bodies to modifiers, thereby maximizing the connectivity and stability of the glass network and resulting in excellent fundamental physical properties. The addition of CsCl serves both as a network modifier to improve glass-forming ability and as an effective nucleating agent for the precipitation of nanocrystals during subsequent heat treatment.

[0008] The CsCl exists in ionic form in the prepared base glass. After specific heat treatment, it is uniformly dispersed in the Sn-Se-Sb-Bi glass matrix in the form of nanocrystals with a size of 10-50 nm to form microcrystalline glass.

[0009] The base glass exhibits excellent overall performance: its average transmittance is not less than 65% in the ultra-wide wavelength range of 8-14μm; at the same time, its glass transition temperature Tg can reach 180-220℃, showing good thermal stability, and it is one of the components with the best physical properties in this system.

[0010] After controlled heat treatment of the base glass, the precipitated CsCl nanocrystals act as a reinforcing phase, increasing the Vickers hardness of the glass-ceramic by more than 30% compared to the base glass, reaching over 2.6 GPa, while simultaneously improving fracture toughness. In the 8-14 μm infrared band, its average transmittance remains above 60%, ensuring transmission performance at long-wave infrared thermal imaging or infrared sensing wavelengths.

[0011] This invention also provides a method for preparing Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass, comprising the following steps:

[0012] S1, weigh out Sn, Se, Sb, Bi elements and CsCl compound with a purity of not less than 99.999% according to the mass percentages Sn: 15%-35%, Se: 40%-60%, Sb: 5%-20%, Bi: 0.1%-12%, CsCl: 3%-8%, mix them evenly in an inert atmosphere glove box, put the mixture into a quartz ampoule that has been cleaned with hydrofluoric acid and treated with high temperature dehydroxylation, connect it to a vacuum system, evacuate to a vacuum degree of more than 10⁻³Pa, and seal it with an oxyhydrogen flame;

[0013] S2. Place the sealed quartz ampoule in a swing furnace and heat it to 750-900℃ at a rate of 2-5℃ / min. Hold it at this temperature for 10-20 hours, and continue to swing it during this period to ensure that the melt is fully homogenized. After the holding period, quickly remove the quartz ampoule and immerse it in room temperature water or use compressed air for rapid cooling (quenching) to obtain a homogeneous and transparent Sn-Se-Sb-Bi-CsCl base glass.

[0014] S3. Place the base glass sample into a precision heat treatment furnace. Proceed with a programmed heating rate of 5-20℃ / min to a specific temperature (i.e., the crystallization temperature range) 20-30℃ above its glass transition temperature (Tg), and hold at this temperature for 3-10 hours to promote uniform nucleation and growth of CsCl into nanocrystals. After holding, slowly cool to room temperature at a controlled cooling rate (e.g., 1-5℃ / min) to obtain the final Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass. The core performance data of the relevant samples, including Vickers hardness, fracture toughness, glass transition temperature, infrared transmittance, and cutoff wavelength, are shown in Table 1.

[0015] Table 1: Core Performance Data of Various Matrix Glass Components and Glass-Ceramic

[0016] Sample number Vickers hardness (GPa) Fracture toughness (MPa·m1 / 2) Glass transition temperature Tg (°C) Average transmittance (%) of 8-14μm Infrared cutoff wavelength (μm) BG-1 1.9 0.18 195 68 15.2 GC-1 2.6 0.25 195 62 15.5 BG-2 1.7 0.16 180 66 21.0 GC-2 2.7 0.22 180 61 20.5 BG-3 1.9 0.17 185 67 16.5 GC-3 2.7 0.23 185 60 16.2 BG-4 1.6 0.15 175 65 19.5 GC-4 2.8 0.20 175 59 19.0 BG-5 1.8 0.165 190 64 17.0 GC-5 2.9 0.21 190 58 16.7

[0017] An application of Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass or Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass containing CsCl nanocrystals in infrared optics, wherein the infrared optical device includes an infrared window, an infrared lens or an optical protective lens, and is particularly suitable for applications such as thermal imaging and infrared sensing that require high mechanical properties, such as automotive and outdoor sports.

[0018] By adopting the aforementioned technical solution, the beneficial effects of the present invention are:

[0019] 1. This invention, through precise design of the Sn-Se-Sb-Bi composition, yields a base glass with optimal physical properties within this system. Simultaneously, it boasts a wide infrared cutoff wavelength of 20 μm and an average transmittance exceeding 65%, providing a high-performance matrix for subsequent reinforcement. Furthermore, it innovatively introduces 3-8% by mass of CsCl as a nucleating agent, successfully inducing the formation of uniformly distributed CsCl nanocrystals through controlled heat treatment. These nanocrystals, acting as an effective reinforcing phase, significantly enhance the material's hardness and toughness (>30%), substantially improving the shortcomings of chalcogenide glasses, such as high brittleness, low hardness, and susceptibility to damage.

[0020] 2. The microcrystalline glass prepared by this invention achieves high strength and high toughness while retaining excellent infrared transmittance (>60%) in its core operating wavelength band (8-14μm). This balance allows the material to meet the mechanical reliability requirements under harsh environments without losing its core function as an infrared optical element, expanding its application potential in high-end infrared imaging, harsh environment optical sensing, and other fields.

[0021] 3. The preparation method provided by this invention is based on mature vacuum sealing and heat treatment technologies, with well-defined process parameters and good repeatability. The material system does not contain highly toxic arsenic, making it more environmentally friendly.

[0022] 4. The basic components of this invention abandon expensive key elements of traditional chalcogenide glasses such as Ge and Ga, and instead use lower-cost Sn, Sb, Bi, and Se as the main components. The nucleating agent CsCl is also a common and inexpensive chemical raw material. This component design significantly reduces raw material costs from the source. At the same time, the microcrystallization heat treatment process has a moderate temperature and short time, requires no complex equipment, and has low energy consumption and high efficiency. Therefore, this invention achieves high performance while having significant advantages in raw materials and manufacturing costs, laying a solid foundation for the large-scale market application of the product. Attached Figure Description

[0023] Figure 1 This is a comparison of the infrared transmission spectra of the base glass (BG-1) and the microcrystalline glass (GC-1) obtained after heat treatment in Embodiment 1 of the present invention.

[0024] Figure 2 This is a comparison of the infrared transmission spectra of the base glass (BG-2) and the microcrystalline glass (GC-2) obtained after heat treatment in Embodiment 2 of the present invention.

[0025] Figure 3 This is a comparison of the infrared transmission spectra of the base glass (BG-3) and the microcrystalline glass (GC-3) obtained after heat treatment in Embodiment 3 of the present invention.

[0026] Figure 4 This is a comparison of the infrared transmission spectra of the base glass (BG-4) and the microcrystalline glass (GC-4) obtained after heat treatment in Example 4 of the present invention.

[0027] Figure 5 This is a comparison of the infrared transmission spectra of the base glass (BG-5) and the microcrystalline glass (GC-5) obtained after heat treatment in Embodiment 5 of the present invention. Detailed Implementation

[0028] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto. Unless otherwise specified, the experimental methods described in the embodiments are conventional methods; unless otherwise specified, the reagents and materials can be obtained commercially.

[0029] Example 1:

[0030] This embodiment aims to obtain glass with the best basic physical properties (especially high-temperature stability), with its infrared window set at about 15 μm.

[0031] 1.1 Component Design:

[0032] Basic glass composition (by mass percentage): Sn: 31.00%, Se: 45.36%, Sb: 12.72%, Bi: 10.92%.

[0033] Microcrystalline glass composition (mass percentage): 5% CsCl was added to the base glass, and the final composition was: Sn: 29.45%, Se: 43.09%, Sb: 12.08%, Bi: 10.37%, CsCl: 5%.

[0034] 1.2 Preparation process:

[0035] S1. Weigh out the high-purity (5N) raw material according to the above proportion, mix it evenly in an argon glove box, place it in a quartz ampoule that has been dehydroxylated, evacuate the vacuum to above 10⁻³Pa and seal it.

[0036] S2, The sealed quartz ampoule is placed in a swing furnace and heated to 850°C at a rate of 3°C / min. It is held for 15 hours, then quenched and annealed to obtain homogeneous and transparent Sn-Se-Sb-Bi-CsCl base glass BG-1.

[0037] S3, The Sn-Se-Sb-Bi-CsCl base glass BG-1 is placed in a heat treatment furnace and heated to 210°C at a rate of 10°C / min. Its glass transition temperature Tg is 195°C. The temperature is held for 3 hours, and then cooled to room temperature at a rate of 2°C / min to obtain Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass GC-1 containing CsCl nanocrystals.

[0038] 1.3 Performance Characterization: This invention provides a comparison of the infrared transmission spectra of the base glass (BG-1) and the microcrystalline glass (GC-1) obtained after heat treatment, as shown in the following embodiments. Figure 1 As shown, based on the data in Table 1 above, we can conclude that:

[0039] Base glass BG-1: The glass transition temperature Tg is 195℃ as measured by DSC. Fourier transform infrared spectroscopy shows an infrared cutoff wavelength (transmittance reduced to 1%) of 15.2 μm, with an average transmittance of 68% in the 8-15 μm band. The Vickers hardness is 1.9 GPa.

[0040] GC-1 microcrystalline glass: XRD shows CsCl crystal diffraction peaks, and TEM observation reveals crystal sizes of approximately 20-40 nm. The Vickers hardness is significantly improved to 2.6 GPa. The average transmittance is 62% in the core working band of 8-14 μm, but decreases to 58% in the 8-15 μm band. Crystallization leads to increased scattering loss on the long-wavelength side (>14 μm), but performance remains good in the main working window.

[0041] Example 2:

[0042] This embodiment aims to achieve a comprehensive balance between a wider infrared window and good mechanical enhancement.

[0043] 2.1 Component Design:

[0044] Basic glass composition (by mass percentage): Sn: 35.48%, Se: 45.62%, Sb: 8.49%, Bi: 10.41%.

[0045] Microcrystalline glass composition (mass percentage): 6% CsCl was added to the base glass, and the final composition was: Sn: 33.35%, Se: 42.88%, Sb: 7.98%, Bi: 9.79%, CsCl: 6%.

[0046] 2.2 Preparation process:

[0047] S1. Weigh out the high-purity (5N) raw material according to the above proportion, mix it evenly in an argon glove box, place it in a quartz ampoule that has been dehydroxylated, evacuate the vacuum to above 10⁻³Pa and seal it.

[0048] S2, The sealed quartz ampoule is placed in a swing furnace and heated to 820°C at a rate of 3°C / min. It is held for 15 hours, then quenched and annealed to obtain homogeneous and transparent Sn-Se-Sb-Bi-CsCl base glass BG-2.

[0049] S3, The Sn-Se-Sb-Bi-CsCl base glass BG-2 is placed in a heat treatment furnace and heated to 200°C at a rate of 15°C / min. Its glass transition temperature Tg is 180°C. The temperature is held for 2 hours, and then cooled to room temperature at a rate of 3°C / min to obtain Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass GC-2 containing CsCl nanocrystals.

[0050] 2.3 Performance Characterization: This embodiment provides a comparison of the infrared transmission spectra of the base glass (BG-2) and the microcrystalline glass (GC-2) obtained after heat treatment, as shown below. Figure 2 As shown in Table 1, we can see that:

[0051] Base glass BG-2: DSC measured glass transition temperature Tg = 180℃. Infrared testing showed its infrared cutoff wavelength extended to 21μm, with an average transmittance of 66% in the ultra-wide 8-21μm band. Vickers hardness is 1.7GPa.

[0052] GC-2 microcrystalline glass: XRD and TEM confirmed the precipitation of CsCl nanocrystals with a size of approximately 15-35 nm. The Vickers hardness was increased to 2.7 GPa. The average transmittance in the core working band of 8-14 μm was 61%, while the average transmittance across the entire 8-21 μm band decreased to approximately 55% due to scattering. It maintained its ultra-wide infrared window characteristics while effectively enhancing its mechanical properties, resulting in optimal overall performance.

[0053] Example 3:

[0054] 3.1 Component Design:

[0055] Basic glass composition (by mass percentage): Sn: 33.97%, Se: 46.81%, Sb: 14.94%, Bi: 4.28%.

[0056] Microcrystalline glass composition (mass percentage): 4% CsCl was added to the base glass, and the final composition was: Sn: 32.61%, Se: 44.94%, Sb: 14.34%, Bi: 4.10%, CsCl: 4%.

[0057] 2. Preparation process:

[0058] S1. Weigh out the high-purity (5N) raw material according to the above proportion, mix it evenly in an argon glove box, place it in a quartz ampoule that has been dehydroxylated, evacuate the vacuum to above 10⁻³Pa and seal it.

[0059] S2, The sealed quartz ampoule is placed in a swing furnace and heated to 830°C at a rate of 4°C / min. It is held for 14 hours, then quenched and annealed to obtain homogeneous and transparent Sn-Se-Sb-Bi-CsCl base glass BG-3.

[0060] S3, the Sn-Se-Sb-Bi-CsCl base glass BG-3 is placed in a heat treatment furnace and heated to 205°C at a rate of 12°C / min. Its glass transition temperature Tg is 185°C. The temperature is held for 4 hours, and then cooled to room temperature at a rate of 2.5°C / min to obtain Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass GC-3 containing CsCl nanocrystals.

[0061] 3.3 Performance Characterization: This embodiment provides a comparison of the infrared transmission spectra of the base glass (BG-3) and the microcrystalline glass (GC-3) obtained after heat treatment, such as... Figure 3 As shown in Table 1, we can see that:

[0062] The base glass BG-3 has an infrared cutoff wavelength of 16.5μm, an average transmittance of 67% in the 8-14μm band, and a Vickers hardness of 1.9GPa.

[0063] The infrared cutoff wavelength of the microcrystalline glass GC-3 is 16.2 μm, the average transmittance in the core working band of 8-14 μm is 60%, the Vickers hardness is increased to 2.7 GPa, and XRD and TEM show that the size of the precipitated CsCl nanocrystals is about 15-30 nm.

[0064] Example 4:

[0065] 4.1 Component Design:

[0066] Basic glass composition (by mass percentage): Sn: 29.78%, Se: 47.55%, Sb: 12.22%, Bi: 10.45%.

[0067] Microcrystalline glass composition (mass percentage): 7% CsCl was added to the base glass, and the final composition was: Sn: 27.69%, Se: 44.22%, Sb: 11.36%, Bi: 9.75%, CsCl: 7%.

[0068] 4.2 Preparation process

[0069] S1. Weigh out the high-purity (5N) raw material according to the above proportion, mix it evenly in an argon glove box, place it in a quartz ampoule that has been dehydroxylated, evacuate the vacuum to above 10⁻³Pa and seal it.

[0070] S2, The sealed quartz ampoule is placed in a swing furnace and heated to 860°C at a rate of 3°C / min. It is held for 18 hours, then quenched and annealed to obtain homogeneous and transparent Sn-Se-Sb-Bi-CsCl base glass BG-4.

[0071] S3, The Sn-Se-Sb-Bi-CsCl base glass BG-4 is placed in a heat treatment furnace and heated to 195°C at a rate of 8°C / min. Its glass transition temperature Tg is 175°C. The temperature is held for 6 hours, and then cooled to room temperature at a rate of 3°C / min to obtain Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass GC-4 containing CsCl nanocrystals.

[0072] 4.3 Performance Characterization: This invention provides a comparison of the infrared transmission spectra of the base glass (BG-4) and the microcrystalline glass (GC-4) obtained after heat treatment, as shown in the embodiments below. Figure 4 As shown in Table 1, we can see that:

[0073] The base glass BG-4 has an infrared cutoff wavelength of 19.5 μm, an average transmittance of 65% in the 8~14 μm band, and a Vickers hardness of 1.6 GPa.

[0074] The infrared cutoff wavelength of the microcrystalline glass GC-4 is 19.0 μm, the average transmittance in the core working band of 8~14 μm is 59%, the Vickers hardness is significantly improved to 2.8 GPa, and XRD and TEM show that the size of the precipitated CsCl nanocrystals is about 20-45 nm.

[0075] Example 5:

[0076] 5.1 Component Design:

[0077] Basic glass composition (by mass percentage): Sn: 35.03%, Se: 42.72%, Sb: 11.98%, Bi: 10.27%.

[0078] Microcrystalline glass composition (mass percentage): 5% CsCl was added to the base glass, and the final composition was: Sn: 33.28%, Se: 40.58%, Sb: 11.38%, Bi: 9.77%, CsCl: 5%.

[0079] 5.2 Preparation process

[0080] S1. Weigh out the high-purity (5N) raw material according to the above proportion, mix it evenly in an argon glove box, place it in a quartz ampoule that has been dehydroxylated, evacuate the vacuum to above 10⁻³Pa and seal it.

[0081] S2, The sealed quartz ampoule is placed in a swing furnace and heated to 880°C at a rate of 2.5°C / min. It is held for 16 hours, then quenched and annealed to obtain homogeneous and transparent Sn-Se-Sb-Bi-CsCl base glass BG-5.

[0082] S3, The Sn-Se-Sb-Bi-CsCl base glass BG-5 is placed in a heat treatment furnace and heated to 210°C at a rate of 15°C / min. Its glass transition temperature Tg is 190°C. The temperature is held for 5 hours, and then cooled to room temperature at a rate of 2°C / min to obtain Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass GC-5 containing CsCl nanocrystals.

[0083] 5.3 Performance Characterization: This invention provides a comparison of the infrared transmission spectra of the base glass (BG-5) and the microcrystalline glass (GC-5) obtained after heat treatment, as shown in the embodiments below. Figure 5 As shown in Table 1, we can see that:

[0084] The base glass BG-5 has an infrared cutoff wavelength of 17.0 μm, an average transmittance of 64% in the 8~14 μm band, and a Vickers hardness of 1.8 GPa.

[0085] The infrared cutoff wavelength of the microcrystalline glass GC-5 is 16.7 μm, the average transmittance in the core working band of 8~14 μm is 58%, the Vickers hardness is increased to 2.9 GPa, and XRD and TEM show that the size of the precipitated CsCl nanocrystals is about 25-50 nm, which is the hardest sample in this series.

[0086] In summary, Examples 1-5 demonstrate that this invention successfully prepared Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass, possessing a wide infrared window, excellent basic physicochemical properties, and enhanced mechanical properties, through precise component design and the introduction of CsCl nucleating agent. By adjusting the specific ratios of Sn, Se, Sb, and Bi, a trade-off can be struck between optimizing physical properties (high Tg) and maximizing the infrared window width. The addition of CsCl and subsequent heat treatment are key to achieving a significant improvement in mechanical properties. The material of this invention holds promise for application in advanced infrared optical systems requiring long-wave infrared detection and high environmental reliability.

[0087] Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass, characterized in that: Its composition, expressed as a percentage by mass, is as follows: Sn: 15%-35%, Se: 40%-60%, Sb: 5%-20%, Bi: 0.1%-12%, CsCl: 3%-8%, and the sum of the percentages of the above components is 100%.

2. A method for preparing Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass according to claim 1, characterized in that: Includes the following steps: S1, weigh the raw materials according to the mass percentage of Sn: 15%-35%, Se: 40%-60%, Sb: 5%-20%, Bi: 0.1%-12%, CsCl: 3%-8%, mix them evenly and place them in a quartz ampoule that has been dehydroxylated, evacuate the vacuum to a degree of 10⁻³Pa or higher and seal it; S2, The sealed quartz ampoule is placed in a swing furnace and heated to 750-900℃ at a rate of 2-5℃ / min, held for 10-20 hours, and then quenched and annealed to obtain homogeneous and transparent Sn-Se-Sb-Bi-CsCl base glass. S3. The base glass is placed in a heat treatment furnace and heated at a rate of 5-20℃ / min to a temperature range of 20-60℃ above its glass transition temperature Tg. The temperature is maintained for 3-8 hours and then cooled to room temperature to obtain Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass containing CsCl nanocrystals.

3. The method for preparing Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass according to claim 2, characterized in that: The purity of Sn, Se, Sb, Bi and CsCl in S1 is not less than 99.999%.

4. The method for preparing Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass according to claim 3, characterized in that: The quenching mentioned in S2 refers to immersing the quartz ampoule in room temperature water or rapidly cooling it with compressed air.

5. The application of Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass containing CsCl nanocrystals prepared by the preparation method of Sn-Se-Sb-Bi-CsCl chalcogenide microcrystalline glass according to claim 1 or any one of claims 2-4 in infrared optics.

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