Barium gallium selenide sulfide and its nonlinear optical crystal and preparation method and use thereof

Abstract

The present application relates to a compound barium selenogallium sulfide and a nonlinear optical crystal thereof, and a preparation method and use thereof, the chemical formula of the compound and the crystal are BaGa4S x Se y (x+y=7, 0

Description

Technical Field

[0001] The present invention relates to a novel barium gallium sulfoselenide compound and its nonlinear optical crystal, wherein the molecular formula of the compound barium gallium sulfoselenide and its crystal is BaGa₄S x Se y (x+y=7, 0<x<7, 0<y<7), and a preparation method for the nonlinear optical crystal and the compound, which belongs to the technical fields of optical technology and crystal material science and technology. Background Art

[0002] Exploring novel nonlinear optical crystals with large frequency doubling effect, wide transmission band, high optical damage threshold and stable physicochemical properties has always been a research hotspot in the field of laser frequency conversion. At present, the main nonlinear optical materials include β-BaB₂O₄ (BBO) crystal, LiB₃O₅ (LBO) crystal, CsB₃O₅ (CBO) crystal, CsLiB₆O 10 (CLBO) crystal and KBe₂BO₃F₂ (KBBF) crystal. Although the crystal growth technologies of these materials have become increasingly mature, there are still obvious shortcomings: for example, the crystals are prone to deliquescence, have long growth cycles, severe layered growth habits and high prices. Therefore, searching for new nonlinear optical crystal materials remains a very important and arduous task. To make up for the above deficiencies of nonlinear optical crystals, scientists from various countries are still devoting great attention to the exploration and research of various new nonlinear optical crystals, not only focusing on the optical and mechanical properties of the crystals, but also paying more and more attention to the preparation characteristics of the crystals.

[0003] Up to now, the generation of 3-20 μm solid-state mid-far infrared band laser is mainly obtained based on the nonlinear optical principle and the frequency conversion technology of infrared nonlinear optical crystals. In the infrared nonlinear optical crystal market, common infrared nonlinear optical crystals mainly include AgGaS₂, AgGaSe₂, ZnGeP₂ and the like. Although these crystals have been applied in the civilian production, life, high-tech fields and military equipment, these crystal materials also have their own shortcomings, and their comprehensive properties cannot meet people's ideal requirements. With the development of technology and the improvement of requirements, the demand for infrared nonlinear crystals with more excellent properties is more urgent. Therefore, the exploration of new mid-far infrared nonlinear crystals is of great strategic significance in the civilian high-tech industry and the improvement of military equipment, and the synthesis and growth of crystal materials with excellent properties is a huge challenge in this direction. Contents of the Invention

[0004] One of the objectives of the present invention is to provide the compound barium gallium sulfoselenide.

[0005] The second objective of the present invention is to provide a preparation method of the compound barium gallium sulfoselenide.

[0006] The third objective of the present invention is to provide a barium gallium sulfoselenide infrared nonlinear optical crystal.

[0007] The fourth objective of the present invention is to provide a preparation method for the barium gallium sulfoselenide infrared nonlinear optical crystal.

[0008] The fifth objective of the present invention is to provide an application of the barium gallium sulfoselenide infrared nonlinear optical crystal.

[0009] The first objective of the present invention is achieved as follows:

[0010] The present invention provides a novel barium gallium sulfoselenide compound, characterized in that the molecular formula of the barium gallium sulfoselenide compound is BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7), which has no symmetry center, belongs to the orthorhombic crystal system, with the space group Pmn21, and the unit cell parameters are α=β=γ=90°, Z=2, and the unit cell volume

[0011] The second objective of the present invention is achieved as follows:

[0012] For the barium gallium sulfoselenide compound provided by the present invention, the barium gallium sulfoselenide compound is prepared by a vacuum high-temperature solid-phase reaction method according to the following chemical reaction equations:

[0013] 1) Ba+Ga+S+Se→BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7)

[0014] 2) Ba+Ga2S3+Ga2Se3+S+Se→BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7)

[0015] 3) Ba+Ga2S3+S+Se→BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7)

[0016] 4) Ba+Ga2S3+Se→BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7)

[0017] 5) Ba+Ga2Se3+S+Se→BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7)

[0018] 6)Ba+Ga2Se3+S→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)

[0019] 7)BaS+Ga+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)

[0020] 8)BaS+Ga2S3+Ga2Se3+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)

[0021] 9)BaS+Ga2S3+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)

[0022] 10)BaS+Ga2S3+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)

[0023] 11)BaS+Ga2Se3+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)

[0024] 12)BaS+Ga2Se3+S→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)

[0025] 13)BaSe+Ga+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)

[0026] 14)BaSe+Ga2S3+Ga2Se3+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)

[0027] 15)BaSe+Ga2S3+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)

[0028] 16)BaSe+Ga2S3+Se→BaGa4Sx HE y (x+y=7, 0 <x<7,0<y<7)

[0029] 17)BaSe+Ga2Se3+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)

[0030] 18)BaSe+Ga2Se3+S→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)

[0031] 19)BaSe+BaS+Ga+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)

[0032] 20)BaSe+BaS+Ga2S3+Ga2Se3+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)

[0033] 21)BaSe+BaS+Ga2S3+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)

[0034] 22)BaSe+BaS+Ga2S3+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)

[0035] 23)BaSe+BaS+Ga2Se3+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)

[0036] 24)BaSe+BaS+Ga2Se3+S→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)

[0037] 25)BaF2+Ga+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)+SF4↑+SeF4↑

[0038] 26)BaF2+Ga2S3+Ga2Se3+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)+SF4↑+SeF4↑

[0039] 27)BaF2+Ga2S3+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)+SF4↑+SeF4↑

[0040] 28)BaF2+Ga2S3+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)+SF4↑+SeF4↑

[0041] 29)BaF2+Ga2Se3+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)+SF4↑+SeF4↑

[0042] 30)BaF2+Ga2Se3+S→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)+SF4↑+SeF4↑

[0043] 31)BaCl2+Ga+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)+SCl4↑+SeCl4↑

[0044] 32)BaCl2+Ga2S3+Ga2Se3+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)+SCl4↑+SeCl4↑

[0045] 33)BaCl2+Ga2S3+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)+SCl4↑+SeCl4↑

[0046] 34)BaCl2+Ga2S3+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)+SCl4↑+SeCl4↑

[0047] 35)BaCl2+Ga2Se3+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)+SCl4↑+SeCl4↑

[0048] 36)BaCl2+Ga2Se3+S→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)+SCl4↑+SeCl4↑

[0049] 37)BaBr2+Ga+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)+SBr4↑+SeBr4↑

[0050] 38)BaBr2+Ga2S3+Ga2Se3+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)+SBr4↑+SeBr4↑

[0051] 39)BaBr2+Ga2S3+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)+SBr4↑+SeBr4↑

[0052] 40)BaBr2+Ga2S3+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)+SBr4↑+SeBr4↑

[0053] 41)BaBr2+Ga2Se3+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)+SBr4↑+SeBr4↑

[0054] 42)BaBr2+Ga2Se3+S→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)+SBr4↑+SeBr4↑

[0055] 43)BaGa2Se4+Ga+S+Se→BaGa4S x HE y (x+y=7, 0 <x<7,0<y<7)

[0056] 44) BaGa2Se4 + Ga2S3 → BaGa4S x Se y (x+y=7,0 <x<7,0<y<7)

[0057] 45) BaGa₂S₄ + Ga + S + Se → BaGa₄S x Se y (x+y=7,0 <x<7,0<y<7)

[0058] 46) BaGa2S4 + Ga2Se3 → BaGa4S x Se y (x+y=7,0 <x<7,0<y<7)

[0059] 47) BaGa2S4 + Se → BaGa4S x Se y (x+y=7,0 <x<7,0<y<7)

[0060] 48) BaGa2S4+S→BaGa4S x Se y (x+y=7,0 <x<7,0<y<7)

[0061] 49) BaGa4S7 + BaGa4Se7 → BaGa4S x Se y (x+y=7,0 <x<7,0<y<7)

[0062] 50) BaGa4S7 + Ga2Se3 → BaGa4S x Se y (x+y=7,0 <x<7,0<y<7)

[0063] 51) BaGa4Se7 + Ga2S3 → BaGa4S x Se y (x+y=7,0 <x<7,0<y<7)

[0064] 52) BaGa4S7 + Se → BaGa4S x Se y (x+y=7,0 <x<7,0<y<7)

[0065] 53) BaGa4Se7+S→BaGa4S x Se y (x+y=7,0 <x<7,0<y<7)

[0066] The third objective of this invention is achieved as follows:

[0067] The present invention provides a barium gallium sulfoselenide nonlinear optical crystal, characterized in that the molecular formula of the barium gallium sulfoselenide nonlinear optical crystal is BaGa₄S x Se y (x+y=7, 0<x<7, 0<y<7), which has no symmetry center, belongs to the orthorhombic crystal system, with space group Pmn2₁, and the unit cell parameters are α=β=γ=90°, Z=2, unit cell volume

[0068] The fourth objective of the present invention is achieved as follows:

[0069] In the preparation method of the barium gallium sulfoselenide nonlinear optical crystal provided by the present invention, the barium gallium sulfoselenide nonlinear optical crystal is grown by a high-temperature solution method or a Bridgman method (crucible descent method), and the specific operations are carried out according to the following steps:

[0070] In a glove box filled with inert gas argon with water content and oxygen content of 0.01-0.1ppm, the single-phase polycrystalline powder of the barium gallium sulfoselenide compound and the flux are uniformly mixed and placed in a clean graphite crucible, then the graphite crucible is loaded into a sealed reaction vessel, and the sealed reaction vessel containing the raw materials is placed under a vacuum degree of 10 -5 -10 -1 Pa for vacuum pumping and then sealing, the temperature is raised from room temperature to 400-600°C at a rate of 10 to 50°C / h, held for 10-120 hours, then raised to 700 to 1200°C at a temperature of 5-40°C / h, held for 10-120 hours to obtain a mixed melt, and cooled to room temperature at a rate of 1-10°C / h; or the above-mentioned sealed reaction vessel containing the vacuum-pumped and sealed mixture is placed in a tubular descending furnace, slowly heated to 400-600°C and heated at constant temperature for 10-120 hours, then heated to 700-1200°C and heated at constant temperature for 10-120 hours. At this time, the crucible descends at a rate of 0.2-2mm / h, then the temperature is lowered to room temperature within 10 hours, and the furnace is turned off. After the sample is cooled, the barium gallium sulfoselenide nonlinear optical crystal is obtained. The molar ratio of the single-phase polycrystalline powder of the barium gallium sulfoselenide compound to the flux is 1:0.1-30.

[0071] Alternatively, in a glove box filled with inert gas argon with water content and oxygen content of 0.01-0.1ppm, the mixture of the barium-containing compound, gallium-containing compound, selenium-containing compound and sulfur-containing compound, or the mixture of the barium-containing compound, gallium-containing compound, selenium-containing compound, sulfur-containing compound and the flux is directly placed in a clean graphite crucible, then the graphite crucible is loaded into a sealed reaction vessel, and the sealed reaction vessel containing the raw materials is placed under a vacuum degree of 10 -5 -10 -1After vacuuming and sealing under Pa conditions, the temperature is increased from room temperature to 400-600℃ at a rate of 10-50℃ / h and held for 10-120 hours. Then, the temperature is increased to 700-1200℃ at a rate of 5-40℃ / h and held for 10-120 hours to obtain a mixed melt. The melt is then cooled to room temperature at a rate of 1-10℃ / h. Alternatively, the sealed reaction vessel containing the mixture, after vacuuming and sealing, is placed in a tubular descending furnace and slowly heated to 400-600℃ and held for 10-120 hours. Then, the temperature is increased to 700-1200℃ and held for 10-120 hours. During this process, the crucible is descended at a rate of 0.2-2 mm / h. After growth, the temperature is lowered to room temperature over 50 hours, the furnace is closed, and the sample is allowed to cool before obtaining the barium selenide-sulfur nonlinear optical crystal. The molar ratio of barium-containing compounds, gallium-containing compounds, selenium-containing compounds, and sulfur-containing compounds to flux is 0.8-1.2:3.8-4.2:1-7:1-7:0-20;

[0072] The flux includes single fluxes and composite fluxes. Single fluxes include at least one of elemental sulfur (S), gallium sulfide (Ga₂S₃), barium sulfide (BaS), barium gallium sulfide (BaGa₂S₄, BaGa₄S₇), elemental selenium (Se), gallium selenide (Ga₂Se₃), barium selenide (BaSe), barium gallium selenide (BaGa₂Se₄, BaGa₄Se₇), barium fluoride (BaF₂), gallium fluoride (GaF₃), barium chloride (BaCl₂), gallium chloride (GaCl₃), barium bromide (BaBr₂), and gallium bromide (GaBr₃). Composite fluxes are formed by mixing any two or more of the single fluxes, such as S-Ga₂S₃, S-BaS, S-BaGa₂S₄, etc. S-BaGa4S7, S-Se, S-Ga2Se3, S-BaSe, S-BaGa2Se4, S-BaGa4Se7, S-BaF2, S-GaF3, S-BaCl2, S-GaCl3, S-BaBr2, S-GaBr3, Ga2S3-BaS, Ga2S3-BaGa2S4, Ga 2S3-BaGa4S7, Ga2S3-Se, Ga2S3-Ga2Se3, Ga2S3-BaSe, Ga2S3-BaGa2Se4, Ga2S3-BaGa4Se7, Ga2S3-BaF2, Ga2S3-GaF3, Ga2S3-BaCl2, Ga2S3-GaCl3, Ga2S 3-BaBr2, Ga2S3-GaBr3, BaS-BaGa2S4, BaS-BaGa4S7, BaS-Se, BaS-Ga2Se3, BaS-BaSe, BaS-BaGa2Se4, BaS-BaGa4Se7, BaS-BaF2, BaS-GaF3, BaS-BaCl2 , BaS-GaCl3, BaS-BaBr2, BaS-GaBr3, BaGa2S4-BaGa4S7, BaGa2S4-Se, BaGa2S4-Ga2Se3, BaGa2S4-BaSe, BaGa2S4-BaGa2Se4, BaGa2S4-BaGa4Se7, BaGa2 S4-BaF2, BaGa2S4-GaF3, BaGa2S4-BaCl2, BaGa2S4-GaCl3, BaGa2S4-BaBr2, BaGa2S4-GaBr3, BaGa4S7-Se, BaGa4S7-Ga2Se3, BaGa4S7-BaSe, BaGa4S7-B aGa2Se4, BaGa4S7-BaGa4Se7, BaGa4S7-BaF2, BaGa4S7-GaF3, BaGa4S7-BaCl2, BaGa4S7-GaCl3, BaGa4S7-BaBr2, BaGa4S7-GaBr3, Se-Ga2Se3, Se-BaSe,Se-BaGa2Se4、Se-BaGa4Se7、Se-BaF2、Se-GaF3、Se-BaCl2、Se-GaCl3、Se-BaBr2、Se-GaBr3、Ga2Se3-BaSe、Ga2Se3-BaGa2Se4、Ga2Se3-BaGa4Se7、Ga2Se3-BaF2、Ga2Se3-GaF3、Ga2Se3-BaCl2、Ga2Se3-GaCl3、Ga2Se3-BaBr2、Ga2Se3-GaBr3、BaSe-BaGa2Se4、BaSe-BaGa4Se7、BaSe-BaF2、BaSe-GaF3、BaSe-BaCl2、BaSe-GaCl3、BaSe-BaBr2、BaSe-GaBr3、BaGa2Se4-BaGa4Se7、BaGa2Se4-BaF2、BaGa2Se4-GaF3、BaGa2Se4-BaCl2、BaGa2Se4-GaCl3、BaGa2Se4-BaBr2、BaGa2Se4-GaBr3、BaGa4Se7-BaF2、BaGa4Se7-GaF3、BaGa4Se7-BaCl2、BaGa4Se7-GaCl3、BaGa4Se7-BaBr2、BaGa4Se7-GaBr3、BaF2-GaF3、BaF2-BaCl2、BaF2-GaCl3、BaF2-BaBr2、BaF2-GaBr3、GaF3-BaCl2、GaF3-GaCl3、GaF3-BaBr2、GaF3-GaBr3、BaCl2-GaCl3、BaCl2-BaBr2、BaCl2-GaBr3、GaCl3-BaBr2、GaCl3-GaBr3、BaBr2-GaBr3、S-BaGa4Se7-BaF2、S-BaGa4Se7-GaF3、S-BaGa4Se7-BaCl2、S-BaGa4Se7-GaCl3、S-BaGa4Se7-BaBr2、S-BaGa4Se7-GaBr3、S-BaGa2Se4-BaGa4Se7、S-BaGa2Se4-BaF2、S-BaGa2Se4-GaF3、S-BaGa2Se4-BaCl2、S-BaGa2Se4-GaCl3、S-BaGa2Se4-BaBr2、S-BaGa2Se4-GaBr3、S-BaSe-BaGa2Se4、S-BaSe-BaGa4Se7、S-BaSe-BaF2、S-BaSe-GaF3、S-BaSe-BaCl2、S-BaSe-GaCl3、S-BaSe-BaBr2、S-BaSe-GaBr3、S-Ga2Se3-BaSe、S-Ga2Se3-BaGa2Se4、S-Ga2Se3-BaGa4Se7、S-Ga2Se3-BaF2、S-Ga2Se3-GaF3、S-Ga2Se3-BaCl2、S-Ga2Se3-GaCl3、S-Ga2Se3-BaBr2、S-Ga2Se3-GaBr3、S-Se-Ga2Se3、S-Se-BaSe、S-Se-BaGa2Se4、S-Se-BaGa4Se7、S-Se-BaF2、S-Se-GaF3、S-Se-BaCl2、S-Se-GaCl3、S-Se-BaBr2、S-Se-GaBr3、S-BaGa4S7-Se、S-BaGa4S7-Ga2Se3、S-BaGa4S7-BaSe、S-BaGa4S7-BaGa2Se4、S-BaGa4S7-BaGa4Se7、S-BaGa4S7-BaF2、S-BaGa4S7-GaF3、S-BaGa4S7-BaCl2、S-BaGa4S7-GaCl3、S-BaGa4S7-BaBr2、S-BaGa4S7-GaBr3、S-BaGa2S4-BaGa4S7、S-BaGa2S4-Se、S-BaGa2S4-Ga2Se3、S-BaGa2S4-BaSe、S-BaGa2S4-BaGa2Se4、S-BaGa2S4-BaGa4Se7、S-BaGa2S4-BaF2、S-BaGa2S4-GaF3、S-BaGa2S4-BaCl2、S-BaGa2S4-GaCl3、S-BaGa2S4-BaBr2、S-BaGa2S4-GaBr3、S-Ga2S3-BaS、S-Ga2S3-BaGa2S4、S-Ga2S3-BaGa4S7、S-Ga2S3-Se、S-Ga2S3-Ga2Se3、S-Ga2S3-BaSe、S-Ga2S3-BaGa2Se4、S-Ga2S3-BaGa4Se7、S-Ga2S3-BaF2、S-Ga2S3-GaF3、S-Ga2S3-BaCl2、S-Ga2S3-GaCl3、S-Ga2S3-BaBr2、S-Ga2S3-GaBr3、S-BaS-BaGa2S4、S-BaS-BaGa4S7、S-BaS-Se、S-BaS-Ga2Se3、S-BaS-BaSe、S-BaS-BaGa2Se4、S-BaS-BaGa4Se7、S-BaS-BaF2、S-BaS-GaF3、S-BaS-BaCl2、S-BaS-GaCl3、S-BaS-BaBr2、S-BaS-GaBr3。、

[0073] The molar ratio of S to Ga2S3 in the S-Ga2S3 system is 1-3:1-3; in the S-BaS system, the molar ratio of S to BaS is 1-3:1-2; in the S-Ga2S3-BaS system, the molar ratio of S, Ga2S3, and BaS is 1-3:1-3:1-2; in the S-BaGa2S4 system, the molar ratio of S to BaGa2S4 is 1-3:1-3; in the S-BaGa4S7 system, the molar ratio of S to BaGa4S7 is 1-3:1-2; in the S-Se system, the molar ratio of S to Se is 1-3:1-2; in the S-Ga2Se3 system, the molar ratio of S to Ga2Se3 is 1-3:1-3; and in the S-BaSe system, the molar ratio of S to BaSe is 1-3. The molar ratio of S to BaGa2Se4 in the S-BaGa2Se4 system is 1-3:1-3; the molar ratio of S to BaGa4Se7 in the S-BaGa4Se7 system is 1-3:1-2; the molar ratio of S to BaF2 in the S-BaF2 system is 1-3:1-2; the molar ratio of S to GaF3 in the S-GaF3 system is 1-3:1-3; the molar ratio of S to BaCl2 in the S-BaCl2 system is 1-3:1-2; the molar ratio of S to GaCl3 in the S-GaCl3 system is 1-3:1-3; the molar ratio of S to BaBr2 in the S-BaBr2 system is 1-3:1-2; the molar ratio of S to GaBr3 in the S-GaBr3 system is 1-3:1-2. In the Ga₂S₃-BaS system, the molar ratio of Ga₂S₃ to BaS is 1-3:1-3; in the Ga₂S₃-BaGa₂S₄ system, the molar ratio of Ga₂S₃ to BaGa₂S₄ is 1-3:1-2; in the Ga₂S₃-BaGa₄S₇ system, the molar ratio of Ga₂S₃ to BaGa₄S₇ is 1-3:1-3; in the Ga₂S₃-Se system, the molar ratio of Ga₂S₃ to Se is 1-3:1-2; in the Ga₂S₃-Ga₂Se₃ system, the molar ratio of Ga₂S₃ to Ga₂Se₃ is 1-3:1-2; in the Ga₂S₃-BaSe system, the molar ratio of Ga₂S₃ to BaSe is 1-3:1-3; in the Ga₂S₃-BaGa₂Se₄ system, the molar ratio of Ga₂S₃ to Se is 1-3:1-2; in the Ga₂S₃-BaGa₂Se₄ system, the molar ratio of Ga₂S₃ to Se is 1-3:1-2; in the Ga₂S₃-BaGa₂Se₄ system, the molar ratio of Ga₂S₃ to BaS is 1-3:1-3 ... The molar ratios of Ga2S3 and BaGa4Se7 in the Ga2S3-BaGa4Se7 system are 1-3:1-2; the molar ratios of Ga2S3 and BaGa4Se7 in the Ga2S3-BaF2 system are 1-3:1-2; the molar ratios of Ga2S3 and GaF3 in the Ga2S3-GaF3 system are 1-3:1-2; the molar ratios of Ga2S3 and BaCl2 in the Ga2S3-BaCl2 system are 1-3:1-3; the molar ratios of Ga2S3 and GaCl3 in the Ga2S3-GaCl3 system are 1-3:1-2; and the molar ratios of Ga2S3 and BaBr2 in the Ga2S3-BaBr2 system are 1-3:1-3.In the Ga2S3-GaBr3 system, the molar ratio of Ga2S3 to GaBr3 is 1-3:1-2; in the BaS-BaGa2S4 system, the molar ratio of BaS to BaGa2S4 is 1-3:1-2; in the BaS-BaGa4S7 system, the molar ratio of BaS to BaGa4S7 is 1-3:1-3; in the BaS-Se system, the molar ratio of BaS to Se is 1-3:1-2; in the BaS-Ga2Se3 system, the molar ratio of BaS to Ga2Se3 is 1-3:1-3; in the BaS-BaSe system, the molar ratio of BaS to BaSe is 1-3:1-2; in the BaS-BaGa2Se4 system, the molar ratio of BaS to BaGa2Se4 is 1-3:1-2; B In the BaS-BaGa4Se7 system, the molar ratio of BaS to BaGa4Se7 is 1-3:1-3; in the BaS-BaF2 system, the molar ratio of BaS to BaF2 is 1-3:1-2; in the BaS-GaF3 system, the molar ratio of BaS to GaF3 is 1-3:1-3; in the BaS-BaCl2 system, the molar ratio of BaS to BaCl2 is 1-3:1-2; in the BaS-GaCl3 system, the molar ratio of BaS to GaCl3 is 1-3:1-2; in the BaS-BaBr2 system, the molar ratio of BaS to BaBr2 is 1-3:1-3; in the BaS-GaBr3 system, the molar ratio of BaS to GaBr3 is 1-3:1-2; in the BaGa2S4-BaG In the a4S7 system, the molar ratio of BaGa2S4 to BaGa4S7 is 1-3:1-3; in the BaGa2S4-Se system, the molar ratio of BaGa2S4 to Se is 1-3:1-2; in the BaGa2S4-Ga2Se3 system, the molar ratio of BaGa2S4 to Ga2Se3 is 1-3:1-2; in the BaGa2S4-BaSe system, the molar ratio of BaGa2S4 to BaSe is 1-3:1-3; in the BaGa2S4-BaGa2Se4 system, the molar ratio of BaGa2S4 to BaGa2Se4 is 1-3:1-2; in the BaGa2S4-BaGa4Se7 system, the molar ratio of BaGa2S4 to BaGa4Se7 is 1-3:1-2. 3; In the BaGa2S4-BaF2 system, the molar ratio of BaGa2S4 to BaF2 is 1-3:1-2; in the BaGa2S4-GaF3 system, the molar ratio of BaGa2S4 to GaF3 is 1-3:1-2; in the BaGa2S4-BaCl2 system, the molar ratio of BaGa2S4 to BaCl2 is 1-3:1-3; in the BaGa2S4-GaCl3 system, the molar ratio of BaGa2S4 to GaCl3 is 1-3:1-2; in the BaGa2S4-BaBr2 system, the molar ratio of BaGa2S4 to BaBr2 is 1-3:1-3; in the BaGa2S4-GaBr3 system, the molar ratio of BaGa2S4 to GaBr3 is 1-3:1-2.In the BaGa4S7-Se system, the molar ratio of BaGa4S7 to Se is 1-3:1-2; in the BaGa4S7-Ga2Se3 system, the molar ratio of BaGa4S7 to Ga2Se3 is 1-3:1-3; in the BaGa4S7-BaSe system, the molar ratio of BaGa4S7 to BaSe is 1-3:1-2; in the BaGa4S7-BaGa2Se4 system, the molar ratio of BaGa4S7 to BaGa2Se4 is 1-3:1-3; in the BaGa4S7-BaGa4Se7 system, the molar ratio of BaGa4S7 to BaGa4Se7 is 1-3:1-2; in the BaGa4S7-BaF2 system, the molar ratio of BaGa4S7 to BaF2 is 1... -3:1-2; In the BaGa4S7-GaF3 system, the molar ratio of BaGa4S7 to GaF3 is 1-3:1-3; In the BaGa4S7-BaCl2 system, the molar ratio of BaGa4S7 to BaCl2 is 1-3:1-2; In the BaGa4S7-GaCl3 system, the molar ratio of BaGa4S7 to GaCl3 is 1-3:1-3; In the BaGa4S7-BaBr2 system, the molar ratio of BaGa4S7 to BaBr2 is 1-3:1-2; In the BaGa4S7-GaBr3 system, the molar ratio of BaGa4S7 to GaBr3 is 1-3:1-2; In the Se-Ga2Se3 system, the molar ratio of Se to Ga2Se3 is 1-3:1-3; In the Se-BaSe system, the molar ratio of Se to BaSe is 1-3:1-2; in the Se-BaGa₂Se₄ system, the molar ratio of Se to BaGa₂Se₄ is 1-3:1-3; in the Se-BaGa₄Se₇ system, the molar ratio of Se to BaGa₄Se₇ is 1-3:1-2; in the Se-BaF₂ system, the molar ratio of Se to BaF₂ is 1-3:1-2; in the Se-GaF₃ system, the molar ratio of Se to GaF₃ is 1-3:1-3; in the Se-BaCl₂ system, the molar ratio of Se to BaCl₂ is 1-3:1-2; in the Se-GaCl₃ system, the molar ratio of Se to GaCl₃ is 1-3:1-3; in the Se-BaBr₂ system, the molar ratio of Se to BaBr₂ is 1-3:1-2 ...2; in the Se-BaBr The molar ratios are 1-3:1-2; in the Se-GaBr3 system, the molar ratio of Se to GaBr3 is 1-3:1-2; in the Ga2Se3-BaSe system, the molar ratio of Ga2Se3 to BaSe is 1-3:1-3; in the Ga2Se3-BaGa2Se4 system, the molar ratio of Ga2Se3 to BaGa2Se4 is 1-3:1-2; in the Ga2Se3-BaGa4Se7 system, the molar ratio of Ga2Se3 to BaGa4Se7 is 1-3:1-3; in the Ga2Se3-BaF2 system, the molar ratio of Ga2Se3 to BaF2 is 1-3:1-2; and in the Ga2Se3-GaF3 system, the molar ratio of Ga2Se3 to GaF3 is 1-3:1-2.In the Ga2Se3-BaCl2 system, the molar ratio of Ga2Se3 to BaCl2 is 1-3:1-3; in the Ga2Se3-GaCl3 system, the molar ratio of Ga2Se3 to GaCl3 is 1-3:1-2; in the Ga2Se3-BaBr2 system, the molar ratio of Ga2Se3 to BaBr2 is 1-3:1-3; in the Ga2Se3-GaBr3 system, the molar ratio of Ga2Se3 to GaBr3 is 1-3:1-2; in the BaSe-BaGa2Se4 system, the molar ratio of BaSe to BaGa2Se4 is 1-3:1-2; in the BaSe-BaGa4Se7 system, the molar ratio of BaSe to BaGa4Se7 is 1-3:1-3; B In the BaSe-BaF2 system, the molar ratio of BaSe to BaF2 is 1-3:1-2; in the BaSe-GaF3 system, the molar ratio of BaSe to GaF3 is 1-3:1-3; in the BaSe-BaCl2 system, the molar ratio of BaSe to BaCl2 is 1-3:1-2; in the BaSe-GaCl3 system, the molar ratio of BaSe to GaCl3 is 1-3:1-2; in the BaSe-BaBr2 system, the molar ratio of BaSe to BaBr2 is 1-3:1-3; in the BaSe-GaBr3 system, the molar ratio of BaSe to GaBr3 is 1-3:1-2; in the BaGa2Se4-BaGa4Se7 system, the molar ratio of BaGa2Se4 to BaGa4S is 1-3:1-2; in the BaGa2Se4-BaGa4Se7 system, the molar ratio of BaGa2Se4 to BaGa4S is 1-3:1-2. The molar ratio of e7 is 1-3:1-3; the molar ratio of BaGa2Se4 to BaF2 in the BaGa2Se4-BaF2 system is 1-3:1-2; the molar ratio of BaGa2Se4 to GaF3 in the BaGa2Se4-GaF3 system is 1-3:1-2; the molar ratio of BaGa2Se4 to BaCl2 in the BaGa2Se4-BaCl2 system is 1-3:1-3; the molar ratio of BaGa2Se4 to GaCl3 in the BaGa2Se4-GaCl3 system is 1-3:1-2; the molar ratio of BaGa2Se4 to BaBr2 in the BaGa2Se4-BaBr2 system is 1-3:1-3; the molar ratio of BaGa2Se4 to GaBr3 in the BaGa2Se4-GaBr2 system is 1-3:1-3; The molar ratio of BaGa2Se4 to GaBr3 in the following systems is 1-3:1-2; the molar ratio of BaGa4Se7 to BaF2 in the BaGa4Se7-BaF2 system is 1-3:1-2; the molar ratio of BaGa4Se7 to GaF3 in the BaGa4Se7-GaF3 system is 1-3:1-3; the molar ratio of BaGa4Se7 to BaCl2 in the BaGa4Se7-BaCl2 system is 1-3:1-2; the molar ratio of BaGa4Se7 to GaCl3 in the BaGa4Se7-GaCl3 system is 1-3:1-3; and the molar ratio of BaGa4Se7 to BaBr2 in the BaGa4Se7-BaBr2 system is 1-3:1-2.In the BaGa4Se7-GaBr3 system, the molar ratio of BaGa4Se7 to GaBr3 is 1-3:1-2; in the BaF2-GaF3 system, the molar ratio of BaF2 to GaF3 is 1-3:1-3; in the BaF2-BaCl2 system, the molar ratio of BaF2 to BaCl2 is 1-3:1-2; in the BaF2-GaCl3 system, the molar ratio of BaF2 to GaCl3 is 1-3:1-3; in the BaF2-BaBr2 system, the molar ratio of BaF2 to BaBr2 is 1-3:1-2; in the BaF2-GaBr3 system, the molar ratio of BaF2 to GaBr3 is 1-3:1-2; in the GaF3-BaCl2 system, the molar ratio of GaF3 to BaCl2 is 1-3. The molar ratio of GaF3 to GaCl3 in the GaF3-GaCl3 system is 1-3:1-2; the molar ratio of GaF3 to BaBr2 in the GaF3-BaBr2 system is 1-3:1-3; the molar ratio of GaF3 to GaBr3 in the GaF3-GaBr3 system is 1-3:1-2; the molar ratio of BaCl2 to GaCl3 in the BaCl2-GaCl3 system is 1-3:1-2; the molar ratio of BaCl2 to BaBr2 in the BaCl2-BaBr2 system is 1-3:1-3; the molar ratio of BaCl2 to GaBr3 in the BaCl2-GaBr3 system is 1-3:1-2; the molar ratio of GaCl3 to BaBr2 in the GaCl3-BaBr2 ... The molar ratios of S, BaGa4Se7, and BaF2 in the S-BaGa4Se7-BaF2 system are 1-3:1-3:1-2; in the S-BaGa4Se7-GaF3 system, the molar ratio of S, BaGa4Se7, and BaF2 is 2-7:1-10:1-6; in the S-BaGa4Se7-BaCl2 system, the molar ratio of S, BaGa4Se7, and BaCl2 is 2-7:1-10:1-6; in the S-BaGa4Se7-GaC... In the l3 system, the molar ratio of S, BaGa4Se7 to GaCl3 is 2-5:1-10:1-3; in the S-BaGa4Se7-BaBr2 system, the molar ratio of S, BaGa4Se7 to BaBr2 is 2-5:1-10:1-3; in the S-BaGa4Se7-GaBr3 system, the molar ratio of S, BaGa4Se7 to GaBr3 is 2-5:1-4:1-10; in the S-BaGa2Se4-BaGa4Se7 system, the molar ratio of S, BaGa2Se4 to BaGa4Se7 is 2-5:1-4:1-10; and in the S-BaGa2Se4-BaF2 system, the molar ratio of S, BaGa2Se4 to BaF2 is 2-7:1-10:1-6.In the S-BaGa2Se4-GaF3 system, the molar ratio of S, BaGa2Se4, and GaF3 is 2.7:1.10:1.6; in the S-BaGa2Se4-BaCl2 system, the molar ratio of S, BaGa2Se4, and BaCl2 is 2.5:1.10:1.3; in the S-BaGa2Se4-GaCl3 system, the molar ratio of S, BaGa2Se4, and GaCl3 is 2.5:1.10:1.3; in the S-BaGa2Se4-BaBr2 system, the molar ratio of S, BaGa2Se4, and BaBr2 is 2.7:1.10:1.6; in the S-BaGa2Se4-GaBr3 system, the molar ratio of S, BaGa2Se4, and GaB is 2.7:1.10:1.6; in the S-BaGa2Se4-GaBr3 system, the molar ratio of S, BaGa2Se4, and GaB is 2.7:1.10:1.6. The molar ratio of r3 is 2.7:1.10:1.6; in the S-BaSe-BaGa2Se4 system, the molar ratio of S, BaSe, and BaGa2Se4 is 2.5:1.10:1.3; in the S-BaSe-BaGa4Se7 system, the molar ratio of S, BaSe, and BaGa4Se7 is 2.5:1.10:1.3; in the S-BaSe-BaF2 system, the molar ratio of S, BaSe, and BaF2 is 1.3:1.3:1.2; in the S-BaSe-GaF3 system, the molar ratio of S, BaSe, and GaF3 is 2.7:1.10:1.6; in the S-BaSe-BaCl2 system, the molar ratio of S, BaSe, and BaCl2 is 2.7:1.1. 0:1-6; In the S-BaSe-GaCl3 system, the molar ratio of S, BaSe, and GaCl3 is 2-5:1-10:1-3; In the S-BaSe-BaBr2 system, the molar ratio of S, BaSe, and BaBr2 is 2-5:1-10:1-3; In the S-BaSe-GaBr3 system, the molar ratio of S, BaSe, and GaBr3 is 2-5:1-4:1-10; In the S-Ga2Se3-BaSe system, the molar ratio of S, Ga2Se3, and BaSe is 2-5:1-4:1-10; In the S-Ga2Se3-BaGa2Se4 system, the molar ratio of S, Ga2Se3, and BaGa2Se4 is 2-7:1-10:1-6; S- In the Ga2Se3-BaGa4Se7 system, the molar ratio of S, Ga2Se3, and BaGa4Se7 is 2.7:1.10:1.6; in the S-Ga2Se3-BaF2 system, the molar ratio of S, Ga2Se3, and BaF2 is 2.5:1.10:1.3; in the S-Ga2Se3-GaF3 system, the molar ratio of S, Ga2Se3, and GaF3 is 2.5:1.10:1.3; in the S-Ga2Se3-BaCl2 system, the molar ratio of S, Ga2Se3, and BaCl2 is 2.7:1.10:1.6; and in the S-Ga2Se3-GaCl3 system, the molar ratio of S, Ga2Se3, and GaCl3 is 2.7:1.10:1.6.In the S-Ga₂Se₃-BaBr₂ system, the molar ratio of S, Ga₂Se₃, and BaBr₂ is 2.5:1.10:1.3; in the S-Ga₂Se₃-GaBr₃ system, the molar ratio of S, Ga₂Se₃, and GaBr₃ is 2.5:1.10:1.3; in the S-Se-Ga₂Se₃ system, the molar ratio of S, Se, and Ga₂Se₃ is 1.3:1.3:1.2; in the S-Se-BaSe system, the molar ratio of S, Se, and BaSe is 2.7:1.10:1.6; in the S-Se-BaGa₂Se₄ system, the molar ratio of S, Se, and BaGa₂Se₄ is 2.7:1.10:1.6; in the S-Se-BaGa₄Se₇ system, the molar ratio of S is 2.7:1.10:1.6; in the S-Se-BaGa₄Se₇ system, the molar ratio of S is 2.5:1.10:1.3; in the S-Se-Ga₂Se₃ system, the molar ratio of S, Se, and BaGa₂Se₄ is 2.7:1.10:1.6; in the S-Se-BaGa₄Se₇ system, the molar ratio of S is 2.5:1.10:1.3; in the S-Se-BaGa₄Se₇ system, the molar ratio of S is 2.5:1.10:1.3; in the S-Se-Ga₂Se₃ system, the molar ratio of S is 2.5:1.10:1.3; in the S-Se-Ga₂Se₃ system, the molar ratio of S The molar ratios of S, Se, and BaF2 in the S-Se-BaF2 system are 2.5:1.10:1.3; in the S-Se-GaF3 system, the molar ratios of S, Se, and GaF3 are 2.5:1.4:1.10; in the S-Se-BaCl2 system, the molar ratios of S, Se, and BaCl2 are 2.5:1.4:1.10; in the S-Se-GaCl3 system, the molar ratios of S, Se, and GaCl3 are 2.7:1.10:1.6; in the S-Se-BaBr2 system, the molar ratios of S, Se, and BaBr2 are 2.7:1.10:1.6; and in the S-Se-GaBr3 system, the molar ratios of S, Se, and BaBr2 are 2.7:1.10:1.6. The molar ratio of Se to GaBr3 is 2.5:1.10:1.3; in the S-BaGa4S7-Se system, the molar ratio of S, BaGa4S7 to Se is 2.5:1.10:1.3; in the S-BaGa4S7-Ga2Se3 system, the molar ratio of S, BaGa4S7 to Ga2Se3 is 2.7:1.10:1.6; in the S-BaGa4S7-BaSe system, the molar ratio of S, BaGa4S7 to BaSe is 2.7:1.10:1.6; in the S-BaGa4S7-BaGa2Se4 system, the molar ratio of S, BaGa4S7 to BaGa2Se4 is 2.5:1.10:1.3; in the S-BaGa4S7-BaG... In the S-BaGa4Se7 system, the molar ratio of S, BaGa4S7, and BaGa4Se7 is 2-5:1-10:1-3; in the S-BaGa4S7-BaF2 system, the molar ratio of S, BaGa4S7, and BaF2 is 2-5:1-10:1-3; in the S-BaGa4S7-GaF3 system, the molar ratio of S, BaGa4S7, and GaF3 is 2-7:1-10:1-6; in the S-BaGa4S7-BaCl2 system, the molar ratio of S, BaGa4S7, and BaCl2 is 2-7:1-10:1-6; and in the S-BaGa4S7-GaCl3 system, the molar ratio of S, BaGa4S7, and GaCl3 is 2-5:1-10:1-3.In the S-BaGa4S7-BaBr2 system, the molar ratio of S, BaGa4S7, and BaBr2 is 2.5:1.10:1.3; in the S-BaGa4S7-GaBr3 system, the molar ratio of S, BaGa4S7, and GaBr3 is 1.3:1.3:1.2; in the S-BaGa2S4-BaGa4S7 system, the molar ratio of S, BaGa2Se4, and BaGa4S7 is 2.7:1.10:1.6; in the S-BaGa2S4-Se system, the molar ratio of S, BaGa2S4, and Se is 2.5:1.10:1.3; and in the S-BaGa2S4-Ga2Se3 system, the molar ratio of S, BaGa2S4, and Ga2Se3 is 2.5:1.1. 0:1-3; In the S-BaGa2S4-BaSe system, the molar ratio of S, BaGa2S4, and BaSe is 1-3:1-3:1-2; In the S-BaGa2S4-BaGa2Se4 system, the molar ratio of S, BaGa2S4, and BaGa2Se4 is 2-7:1-10:1-6; In the S-BaGa2S4-BaGa4Se7 system, the molar ratio of S, BaGa2S4, and BaGa4Se7 is 2-7:1-10:1-6; In the S-BaGa2S4-BaF2 system, the molar ratio of S, BaGa2S4, and BaF2 is 2-5:1-10:1-3; In the S-BaGa2S4-GaF3 system, the molar ratio of S, BaGa2S4, and GaF3 is 2-5:1-10:1-3. The molar ratios of S, BaGa2S4, and BaCl2 in the S-BaGa2S4-BaCl2 system are 2.5:1.10:1.3; in the S-BaGa2S4-GaCl3 system, the molar ratios of S, BaGa2S4, and GaCl3 are 2.5:1.4:1.10; in the S-BaGa2S4-BaBr2 system, the molar ratios of S, BaGa2S4, and BaBr2 are 2.7:1.10:1.6; in the S-BaGa2S4-GaBr3 system, the molar ratios of S, BaGa2S4, and GaBr3 are 2.7:1.10:1.6; and in the S-Ga2S3-BaS system, the molar ratios of S, Ga2S3, and BaS are 2.5:1.10:1.3. The molar ratios of S, Ga2S3, and BaGa2S4 in the S-Ga2S3-BaGa2S4 system are 2-5:1-10:1-3; the molar ratios of S, Ga2S3, and BaGa4S7 in the S-Ga2S3-BaGa4S7 system are 2-7:1-10:1-6; the molar ratios of S, Ga2S3, and Se in the S-Ga2S3-Se system are 2-7:1-10:1-6; the molar ratios of S, Ga2S3, and Ga2Se3 in the S-Ga2S3-Ga2Se3 system are 2-5:1-10:1-3; and the molar ratios of S, Ga2S3, and BaSe in the S-Ga2S3-BaSe system are 2-5:1-10:1-3.In the S-Ga₂S₃-BaGa₂Se₄ system, the molar ratio of S, Ga₂S₃, and BaGa₂Se₄ is 1-3:1-3:1-2; in the S-Ga₂S₃-BaGa₄Se₇ system, the molar ratio is 2-7:1-10:1-6; in the S-Ga₂S₃-BaF₂ system, the molar ratio is 2-7:1-10:1-6; in the S-Ga₂S₃-GaF₃ system, the molar ratio is 2-5:1-10:1-3; and in the S-Ga₂S₃-BaCl₂ system, the molar ratio is 2-5:1-10:1-3. The molar ratio of S, Ga2S3, and GaCl3 in the S-Ga2S3-GaCl3 system is 2.5:1.4:1.10; the molar ratio of S, Ga2S3, and BaBr2 in the S-Ga2S3-BaBr2 system is 2.5:1.4:1.10; the molar ratio of S, Ga2S3, and GaBr3 in the S-Ga2S3-GaBr3 system is 2.7:1.10:1.6; the molar ratio of S, BaS, and BaGa2S4 in the S-BaS-BaGa4S7 system is 2.5:1.10:1.3; the molar ratio of S, BaS, and BaGa4S7 in the S-BaS-BaGa4S7 system is 1.3:1.3:1. 2; In the S-BaS-Se system, the molar ratio of S, BaS, and Se is 2.7:1.10:1.6; In the S-BaS-Ga2Se3 system, the molar ratio of S, BaS, and Ga2Se3 is 2.7:1.10:1.6; In the S-BaS-BaSe system, the molar ratio of S, BaS, and BaSe is 2.5:1.10:1.3; In the S-BaS-BaGa2Se4 system, the molar ratio of S, BaS, and BaGa2Se4 is 2.5:1.10:1.3; In the S-BaS-BaGa4Se7 system, the molar ratio of S, BaS, and BaGa4Se7 is 2.5:1.4:1.10; In the S-BaS-BaF2 system, S... The molar ratio of S, BaS, and BaF2 in the S-BaS-GaF3 system is 2.5:1.4:1.10; the molar ratio of S, BaS, and GaF3 in the S-BaS-GaF3 system is 2.7:1.10:1.6; the molar ratio of S, BaS, and BaCl2 in the S-BaS-BaCl2 system is 2.7:1.10:1.6; the molar ratio of S, BaS, and GaCl3 in the S-BaS-GaCl3 system is 2.5:1.10:1.3; the molar ratio of S, BaS, and GaBr2 in the S-BaS-BaBr2 system is 2.5:1.10:1.3; and the molar ratio of S, BaS, and GaBr3 in the S-BaS-GaBr3 system is 1.3:1.3:1.2.

[0074] The fifth objective of this invention is achieved as follows:

[0075] The aforementioned barium gallium sulfoselenide crystal is suitable for mid-far infrared band laser frequency doubling crystals, infrared communication devices, and infrared laser guidance devices, and can also be used to fabricate frequency doublers, up or down frequency converters, or optical parametric oscillators. Brief Description of the Drawings

[0076] Figure 1 is the theoretical X-ray spectrum diagram of the compound BaGa₄S prepared in the present invention x Se y (x+y=7, 0<x<7, 0<y<7) crystal.

[0077] Figure 2 is the crystal structure diagram of BaGa₄S of the present invention x Se y (x+y=7, 0<x<7, 0<y<7) of the present invention;

[0078] Figure 3 is the working principle diagram of the nonlinear optical device fabricated according to the present invention, in which 1 is a reflector, 2 is a Q-switch, 3 is a polarizer, 4 is Nd:YAG, 5 is an OPO input mirror, 6 is a KTP crystal, 7 is an OPO output mirror and a total reflector for light with a wavelength of 1064 nm, 8 is a reflector for light with a wavelength of 2.1 μm, and 9 is the BaGa₄S that has undergone crystal post-treatment and optical processing x Se y (x+y=7, 0<x<7, 0<y<7) single crystal, and 10 is the generated output laser beam. Detailed Description of the Embodiments

[0079] The present invention will be described in detail below with reference to the accompanying drawings and embodiments, but the present invention is not limited to the described embodiments.

[0080] Embodiment 1:

[0081] According to the reaction formula: Ba+Ga+S+Se→BaGa₄S x Se y (x+y=7, 0<x<7, 0<y<7) to prepare the compound barium gallium sulfoselenide:

[0082] In a glove box filled with inert gas argon with a water content of 0.05 ppm and an oxygen content of 0.05 ppm respectively, the starting materials are weighed at a molar ratio of Ba:Ga:S:Se of 1:4:3.5:3.5. The weighed materials are mixed uniformly, carefully ground in a mortar, then placed in a clean graphite crucible, the graphite crucible is placed into a quartz tube, and the quartz tube is evacuated to 10 -1Pa and melt-sealed, the sealed quartz tube is placed in a well-type muffle furnace, heated to 400°C at a rate of 30°C / h, held at this temperature for 10 h, then heated to 1150°C at a rate of 30°C / h, held at this temperature for 100 h, and then cooled down to room temperature at a rate of 5°C / h, to obtain the compound BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7) single-phase polycrystalline powder. X-ray analysis is performed on this product, and the obtained X-ray spectrum is consistent with the X-ray spectrum obtained from the single crystal structure of BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7).

[0083] The above single-phase polycrystalline powder is carefully ground in a mortar, then placed in a clean graphite crucible, the graphite crucible is placed into a quartz tube, and the quartz tube is evacuated to 10 -1 Pa and melt-sealed, the sealed quartz tube is placed in a well-type muffle furnace, heated to 400°C at a rate of 10°C / h, held at this temperature for 10 h, then heated to 1150°C at a rate of 10°C / h, held at this temperature for 120 h, and then cooled down to room temperature at a rate of 5°C / h, to obtain BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7) crystal.

[0084] Example 2

[0085] According to the reaction formula: BaS+BaSe+Ga2S3+Ga2Se3→BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7), the compound barium gallium sulfoselenide is prepared:

[0086] In a glove box filled with inert gas argon with a water content of 0.05 ppm and an oxygen content of 0.05 ppm respectively, the starting materials are weighed at a molar ratio of BaS:BaSe:Ga2S3:Ga2Se3 of 0.5:0.5:1:1. The weighed raw materials are mixed uniformly, carefully ground in a mortar, then placed in a clean graphite crucible, the graphite crucible is placed into a quartz tube, and the quartz tube is evacuated to 10 -5 Pa and melt-sealed, the sealed quartz tube is placed in a well-type muffle furnace, heated to 400°C at a rate of 20°C / h, held at this temperature for 10 h, then heated to 1150°C at a rate of 20°C / h, held at this temperature for 100 h, and then cooled down to room temperature at a rate of 5°C / h, to obtain the compound BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7) single-phase polycrystalline powder. X-ray analysis is performed on this product, and the obtained X-ray spectrum is consistent with that of BaGa4S xSe y (x+y=7, 0<x<7, 0<y<7) single crystal structure are consistent with the obtained X-ray spectrum.

[0087] The above single-phase polycrystalline powder is carefully ground in a mortar, then placed into a clean graphite crucible, the graphite crucible is placed into a quartz tube, and the quartz tube is evacuated to 10 -5 Pa and sealed by melting. The sealed quartz tube is placed in a well-type muffle furnace, heated to 400°C at a rate of 20°C / h, held for 20 h, then heated to 1150°C at a rate of 20°C / h, held for 120 h, and then cooled to room temperature at a rate of 5°C / h to obtain BaGa₄S x Se y (x+y=7, 0<x<7, 0<y<7) crystal.

[0088] Example 3

[0089] According to the reaction formula: BaGa₄S₇+BaGa₄Se₇→BaGa₄S x Se y (x+y=7, 0<x<7, 0<y<7), the compound barium gallium sulfoselenide is prepared:

[0090] In a glove box filled with inert gas argon with a water content of 0.05ppm and an oxygen content of 0.05ppm respectively, the starting materials are weighed according to the molar ratio of BaGa₄S₇:BaGa₄Se₇ of 1:1. The weighed raw materials are mixed uniformly, carefully ground in a mortar, then placed into a clean graphite crucible, the graphite crucible is placed into a quartz tube, and the quartz tube is evacuated to 10 -3 Pa and sealed by melting. The sealed quartz tube is placed in a well-type muffle furnace, heated to 500°C at a rate of 20°C / h, held for 10 h, then heated to 1150°C at a rate of 20°C / h, held for 100 h, and then cooled to room temperature at a rate of 5°C / h to obtain the compound BaGa₄S x Se y (x+y=7, 0<x<7, 0<y<7) single-phase polycrystalline powder. X-ray analysis is performed on the product, and the obtained X-ray spectrum is consistent with the X-ray spectrum obtained from the BaGa₄S x Se y (x+y=7, 0<x<7, 0<y<7) single crystal structure.

[0091] The above single-phase polycrystalline powder is carefully ground in a mortar, then placed into a clean graphite crucible, the graphite crucible is placed into a quartz tube, and the quartz tube is evacuated to 10 -5Pa, then melt and seal it. Place the sealed quartz tube in a well-type muffle furnace, raise the temperature to 500°C at a rate of 20°C / h, hold the temperature for 20h, then raise the temperature to 1150°C at a rate of 20°C / h, hold the temperature for 120h, and then cool down to room temperature at a rate of 3°C / h to obtain BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7) crystal.

[0092] Example 4

[0093] According to the reaction formula: BaGa2S4+Ga2Se3→BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7), the compound gallium barium sulfoselenide is prepared:

[0094] In a glove box filled with inert gas argon with a water content of 0.05ppm and an oxygen content of 0.05ppm respectively, the starting materials are weighed at a molar ratio of BaGa2S4:Ga2Se3 of 1:1. The weighed materials are mixed uniformly and then carefully ground in a mortar, then placed in a clean graphite crucible, the graphite crucible is placed into a quartz tube, and the quartz tube is evacuated to 10 -2 Pa, then melt and seal it. Place the sealed quartz tube in a well-type muffle furnace, raise the temperature to 500°C at a rate of 20°C / h, hold the temperature for 20h, then raise the temperature to 1150°C at a rate of 20°C / h, hold the temperature for 80h, and then cool down to room temperature at a rate of 4°C / h to obtain the compound BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7) single-phase polycrystalline powder. X-ray analysis is performed on the product, and the obtained X-ray spectrum is consistent with the X-ray spectrum obtained from the BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7) single crystal structure.

[0095] The above single-phase polycrystalline powder is carefully ground in a mortar, then placed in a clean graphite crucible, the graphite crucible is placed into a quartz tube, and the quartz tube is evacuated to 10 -5 Pa, then melt and seal it. Place the sealed quartz tube in a well-type muffle furnace, raise the temperature to 1200°C at a rate of 30°C / h, hold the temperature for 120h, and then cool down to room temperature at a rate of 3°C / h to obtain BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7) crystal.

[0096] Example 5

[0097] According to the reaction formula: BaGa2Se4+Ga2S3→BaGa4S xSe y (x+y=7, 0<x<7, 0<y<7) to prepare the barium gallium sulfoselenide compound:

[0098] In a glove box filled with inert gas argon, with the water content and oxygen content being 0.05ppm respectively, the starting materials are weighed at a molar ratio of BaGa₂Se₄: Ga₂S₃ of 1:1. The weighed materials are mixed uniformly, placed in a mortar for thorough grinding, then put into a clean graphite crucible, the graphite crucible is placed into a quartz tube, and the quartz tube is evacuated to 10 -5 Pa and sealed by melting. The sealed quartz tube is placed into a well-type muffle furnace, heated to 500°C at a rate of 20°C / h, held for 10h, then heated to 1200°C at a rate of 20°C / h, held for 100h, and then cooled to room temperature at a rate of 6°C / h, to obtain the compound BaGa₄S x Se y (x+y=7, 0<x<7, 0<y<7) single-phase polycrystalline powder. The product is subjected to X-ray analysis, and the obtained X-ray spectrum is consistent with the X-ray spectrum obtained from the single crystal structure of BaGa₄S x Se y (x+y=7, 0<x<7, 0<y<7).

[0099] The above single-phase polycrystalline powder is thoroughly ground in a mortar, then placed into a clean graphite crucible, the graphite crucible is placed into a quartz tube, and the quartz tube is evacuated to 10 -5 Pa and sealed by melting. The sealed quartz tube is placed into a well-type muffle furnace, heated to 500°C at a rate of 50°C / h, held for 20h, then heated to 1150°C at a rate of 50°C / h, held for 120h, and then cooled to room temperature at a rate of 5°C / h, to obtain BaGa₄S x Se y (x+y=7, 0<x<7, 0<y<7) crystal.

[0100] Example 6

[0101] According to the reaction formula: Ba+Ga₂S₃+Ga₂Se₃+S+Se→BaGa₄S x Se y (x+y=7, 0<x<7, 0<y<7) to prepare the barium gallium sulfoselenide compound:

[0102] In a glove box filled with inert gas argon, with the water content and oxygen content being 0.05ppm respectively, the starting materials are weighed at a molar ratio of Ba: Ga₂S₃: Ga₂Se₃: S: Se of 1:1:1:1:1. The weighed materials are mixed uniformly, placed in a mortar for thorough grinding, then put into a clean graphite crucible, the graphite crucible is placed into a quartz tube, and the quartz tube is evacuated to 10-2 Pa and performing melting and sealing, placing the sealed quartz tube into a well-type muffle furnace, raising the temperature to 300°C at a rate of 20°C / h, holding the temperature for 20 h, then raising the temperature to 1150°C at a rate of 50°C / h, holding the temperature for 100 h, then cooling down to room temperature at a rate of 6°C / h, to obtain the compound BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7) single-phase polycrystalline powder. X-ray analysis is performed on the product, and the obtained X-ray spectrum is consistent with the X-ray spectrum obtained from the BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7) single crystal structure.

[0103] The above single-phase polycrystalline powder is carefully ground in a mortar, then placed into a clean graphite crucible, the graphite crucible is placed into a quartz tube, and the quartz tube is evacuated to 10 -5 Pa and performing melting and sealing, placing the sealed quartz tube into a well-type muffle furnace, raising the temperature to 500°C at a rate of 50°C / h, holding the temperature for 20 h, then raising the temperature to 1200°C at a rate of 50°C / h, holding the temperature for 120 h, then cooling down to room temperature at a rate of 3°C / h, to obtain BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7) crystal.

[0104] Example 7

[0105] According to the reaction formula: BaS+BaSe+Ga+S+Se→BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7), the compound barium gallium sulfoselenide is prepared:

[0106] In a glove box filled with inert gas argon with a water content of 0.05 ppm and an oxygen content of 0.05 ppm respectively, the starting materials are weighed according to the molar ratio of BaS:BaSe:Ga:S:Se of 0.5:0.5:4:3:3, the weighed raw materials are mixed uniformly and then carefully ground in a mortar, then placed into a clean graphite crucible, the graphite crucible is placed into a quartz tube, and the quartz tube is evacuated to 10 -3 Pa and performing melting and sealing, placing the sealed quartz tube into a well-type muffle furnace, raising the temperature to 300°C at a rate of 20°C / h, holding the temperature for 20 h, then raising the temperature to 1150°C at a rate of 50°C / h, holding the temperature for 100 h, then cooling down to room temperature at a rate of 6°C / h, to obtain the compound BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7) single-phase polycrystalline powder. X-ray analysis is performed on the product, and the obtained X-ray spectrum is consistent with the X-ray spectrum of BaGa4S xSe y The X-ray spectra obtained from the single crystal structures (x+y=7, 0<x<7, 0<y<7) are consistent.

[0107] The above single-phase polycrystalline powder is carefully ground in a mortar, then placed into a clean graphite crucible, the graphite crucible is placed into a quartz tube, and the quartz tube is evacuated to 10 -5 Pa and sealed by melting. The sealed quartz tube is placed into a well-type muffle furnace, heated to 500°C at a rate of 50°C / h, held for 20 h, then heated to 1200°C at a rate of 50°C / h, held for 120 h, and then cooled to room temperature at a rate of 4°C / h to obtain BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7) crystal.

[0108] Example 8

[0109] According to the reaction formula: BaGa2S4+BaGa2Se4→BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7), the compound barium gallium sulfoselenide is prepared:

[0110] In a glove box filled with inert gas argon with a water content of 0.05 ppm and an oxygen content of 0.05 ppm respectively, the starting materials are weighed according to the molar ratio of BaGa2S4: BaGa2Se4 of 1:1. The weighed materials are mixed uniformly, carefully ground in a mortar, then placed into a clean graphite crucible, the graphite crucible is placed into a quartz tube, and the quartz tube is evacuated to 10 -5 Pa and sealed by melting. The sealed quartz tube is placed into a well-type muffle furnace, heated to 500°C at a rate of 30°C / h, held for 20 h, then heated to 1100°C at a rate of 50°C / h, held for 100 h, and then cooled to room temperature at a rate of 5°C / h to obtain the BaGa4S compound x Se y (x+y=7, 0<x<7, 0<y<7) single-phase polycrystalline powder. The product is subjected to X-ray analysis, and the obtained X-ray spectrum is consistent with the X-ray spectrum obtained from the BaGa4S x Se y (x+y=7, 0<x<7, 0<y<7) single crystal structure.

[0111] The above single-phase polycrystalline powder is carefully ground in a mortar, then placed into a clean graphite crucible, the graphite crucible is placed into a quartz tube, and the quartz tube is evacuated to 10 -5evacuate and perform melting sealing, place the sealed quartz tube into a well-type muffle furnace, raise the temperature to 50°C at a rate of 60°C / h, hold the temperature for 20h, then raise the temperature to 1150°C at a rate of 70°C / h, hold the temperature for 120h, then cool down to room temperature at a rate of 5°C / h, to obtain BaGa₄S x Se y (x+y=7, 0<x<7, 0<y<7) crystal.

[0112] Example 9

[0113] Any one of the barium gallium sulfoselenide nonlinear optical crystals obtained in Examples 1 to 8 is processed into a frequency doubling device with a size of 5mm×5mm×6mm along the phase matching direction, according to the attached Figure 3 shown and placed at position 3, the infrared light beam 2 with a wavelength of 2090nm emitted from the laser 1 enters BaGa₄S x Se y (x+y=7, 0

Claims

1. A barium selenide-sulfur-gallium nonlinear optical crystal, characterized in that, The chemical formula of this crystal is BaGa4S. x Se y (x + y = 7, 0 < x < 7, 0 < y < 7), belongs to the orthorhombic crystal system, space group is Pmn 21, cell parameters a = 6.9625(5)-7.9625(5) Å, b = 5.8864(4)-6.8864(4) Å, c = 11.8308(7)-12.8308(7) Å, α = β = γ = 90°, Z = 2, unit cell volume V = 582.67(6)-592.67(6) Å 3 .

2. The method for preparing the barium selenide-sulfur-gallium nonlinear optical crystal according to claim 1, characterized in that, Nonlinear optical crystals of gallium-sulfur gallium-barium selenide are grown using either the high-temperature solution method or the Bridgman method.

3. The method according to claim 2, characterized in that, The specific operation is carried out according to the following steps: With a water content and oxygen content of 0.01-0.1%. In a glove box filled with inert argon gas, barium selenide-sulfur gallium-barium single-phase polycrystalline powder is directly placed into a clean graphite crucible, or a mixture of powder and flux is placed into a clean graphite crucible. This mixture is then placed into a sealed reaction vessel. The sealed reaction vessel containing the raw materials is evacuated and sealed. The sealed reaction vessel is then placed in a high-temperature furnace and heated until melting to obtain a mixed molten liquid. The mixture is then cooled or kept at a constant temperature to grow, thus preparing barium selenide-sulfur gallium-barium crystals. Alternatively, a sealed reaction vessel containing barium selenide-sulfur gallium-barium single-phase polycrystalline powder is placed directly into a clean graphite crucible, or a mixture of powder and flux is placed into a tubular descending furnace. The furnace is slowly lowered through a heating furnace with a specific temperature gradient, controlling the furnace temperature slightly above the melting point of the compound. A suitable heating zone is selected. As the crucible passes through the heating zone, the mixture in the crucible melts. As the crucible continues to descend, the temperature at the bottom first drops below the melting point, and crystallization begins. The crystal continues to grow as the crucible descends, thus preparing barium selenide-sulfur gallium-barium crystals. Alternatively, in a glove box filled with inert argon gas and an airtight container with a water and oxygen content of 0.01-0.1 ppm, a mixture of barium, gallium, sulfur, and selenium compounds, or a mixture of barium, gallium, sulfur, and selenium compounds with a flux, can be directly heated to melt to obtain a mixed molten liquid, followed by cooling or isothermal growth to prepare barium selenide-sulfur-gallium-barium crystals. Alternatively, a sealed reaction vessel containing a mixture of barium, gallium, sulfur, and selenium compounds, or a mixture of barium, gallium, sulfur, and selenium compounds with a flux, can be placed in a tubular descending furnace and slowly lowered through a heating furnace with a certain temperature gradient, controlling the furnace temperature slightly above the melting point of the compounds. A suitable heating zone is selected; as the crucible passes through the heating zone, the mixture in the crucible melts. As the crucible continues to descend, the temperature at the bottom of the crucible first drops below the melting point and crystallization begins. The crystals continue to grow as the crucible descends, thus preparing barium selenide-sulfur-gallium-barium crystals.

4. The method according to claim 2, characterized in that... The molar ratio of the compound barium selenide-sulfur gallium to the flux is 1-1.2:0-20; or the molar ratio of the barium-containing compound, gallium-containing compound, sulfur-containing compound, selenium-containing compound, and flux is 1-1.2:4-4.2:3-4:3-4:0-20; the flux includes single flux and composite flux, and the single flux includes at least one of elemental sulfur, gallium sulfide, barium sulfide, barium gallium sulfide, elemental selenium, gallium selenide, barium selenide, barium gallium selenide, barium fluoride, gallium fluoride, barium chloride, gallium chloride, barium bromide, and gallium bromide; the composite flux is formed by mixing any two or more of the single fluxes.

5. The use of the barium selenide-sulfur-gallium nonlinear optical crystal according to claim 1, characterized in that, This barium selenide-sulfur gallium-barium nonlinear optical crystal is used in the fabrication of infrared communication devices, infrared laser frequency doubling crystals, infrared laser guidance devices, up-frequency converters, down-frequency converters, or optical parametric oscillators.

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