Compound boric acid strontium nitrate, boric acid strontium nitrate nonlinear optical crystal, and preparation method and application of boric acid strontium nitrate nonlinear optical crystal

Abstract

The invention relates to a compound boric acid strontium nitrate, a boric acid strontium nitrate nonlinear optical crystal and a preparation method and application thereof, the chemical formula of the compound is Sr3B9O16 (NO3), the molecular weight is 678.16, and the compound is prepared by adopting a vacuum tube sealing method; the chemical formula of the crystal is Sr3B9O16 (NO3), the molecular weight is 678.16, the crystal belongs to a monoclinic system, the space group is Cc, and the cell parameters are as follows: a is equal to 11.2574 (9), b is equal to 6.6400 (9), c is equal to 18.1027 (13), Z is equal to 4, and V is equal to 1348.9 (2) 3. The material is prepared by adopting a high-temperature melting method or a hydrothermal method under a vacuum sealing condition, the nonlinear optical effect of the material is about 3 times that of KDP, and the birefringence of the material is 0.088 at-546 nm. The method has the advantages of simple preparation, short growth cycle, low toxicity of the used initial raw materials, small toxicity to human bodies and the like. The Sr3B9O16 (NO3) nonlinear optical crystal obtained through the method is stable in physicochemical property, has a large nonlinear effect, can be applied to phase matching wavelength of an ultraviolet band, and can be widely applied to nonlinear optical devices such as frequency doubling conversion and optical parametric oscillators.

Description

Technical Field

[0001] The present invention relates to a compound strontium borate nitrate and a strontium borate nitrate nonlinear optical crystal as well as a preparation method and application thereof. Background Art

[0002] In recent years, the research and development of second-order nonlinear optical crystal materials has yielded significant advances in areas such as laser-driven interferometric lithography, precision micromachining, and nanosecond and picosecond pulse generation. Since Franken et al. first observed the second harmonic radiation of a ruby laser in a quartz crystal in 1961, nonlinear optics, as a key branch of modern optics, has made significant progress. Given the extremely limited number of natural crystals exhibiting significant nonlinear optical effects, many chemists and materials scientists have focused their attention on synthetic nonlinear optical materials, hoping to obtain materials with superior optical properties. The research and development and application of nonlinear optical crystal materials have matured across the visible to near-infrared spectrum, with representative materials such as KTiOPO4 (KTP) and KH2PO4 (KDP). For infrared applications, commercial nonlinear optical crystals include AgGaS2, AgGaSe2, and ZnGeP2.

[0003] In the ultraviolet band, the industrialized nonlinear optical crystals LiB3O5 (LBO), CsB3O5 (CBO), CsLiB6O 10 (CLBO) and BaB2O4 (BBO), among others. KBBF family crystals are the third Chinese-made nonlinear optical crystals in my country's nonlinear optical crystal research, following the discovery of BBO and LBO crystals. They have played a pioneering role in promoting the development and application of all-solid-state deep ultraviolet laser sources, and fully demonstrate that my country continues to maintain an international leading position in the field of nonlinear optical crystals. Research has shown that borate systems have rapidly become an important source of materials for the design of ultraviolet nonlinear optical crystals due to their rich and diverse structural types, tendency to crystallize in non-centrosymmetric space groups, and excellent overall optical properties. The search and development of new ultraviolet nonlinear optical crystals with excellent comprehensive properties within the borate system remains a key research focus in this field. Summary of the Invention

[0004] The purpose of the present invention is to provide a compound strontium borate nitrate, the chemical formula of which is Sr3B9O 16 (NO3), molecular weight 678.16, was prepared by vacuum sealing tube method.

[0005] Another object of the present invention is to provide a strontium borate nitrate nonlinear optical crystal with a large nonlinear coefficient, a short phase matching wavelength, easy preparation and good stability. The chemical formula of the crystal is Sr3B9O 16(NO3), molecular weight is 678.16, belongs to monoclinic system, space group is Cc, unit cell parameters are Z=4, Shortest phase matching wavelength

[0006] Another object of the present invention is to provide a method for preparing strontium borate nitrate nonlinear optical crystals.

[0007] Another object of the present invention is to provide a use of strontium borate nitrate nonlinear optical crystal.

[0008] The compound strontium borate nitrate described in the present invention has the chemical formula Sr3B9O 16 (NO3), molecular weight 678.16, made in vacuum sealed tubes.

[0009] The preparation method of the compound strontium borate nitrate adopts a vacuum sealing tube method, and the specific operation is carried out according to the following steps:

[0010] The Sr-containing compound, the B-containing compound and the N-containing compound were mixed evenly in a molar ratio of Sr:B:N=2-4:8-11:0.5-2, and placed in a quartz tube of Ø10mm×100mm. The quartz tube was evacuated to a vacuum degree of 1×10 -3 Pa, flame sealed at high temperature, placed in a muffle furnace, heated to 500-750℃ at a rate of 10-50℃ / h, kept constant for 1-10 days, and slowly cooled to obtain the compound Sr3B9O 16 (NO3), wherein the Sr-containing compound is Sr(NO3)2, SrCO3 or SrO, the B-containing compound is H3BO3 or B2O3, and the N-containing compound is Sr(NO3)2.

[0011] A strontium borate nitrate nonlinear optical crystal, the chemical formula of the crystal is Sr3B9O 16 (NO3), molecular weight is 678.16, the crystal belongs to the monoclinic system, the space group is Cc, and the unit cell parameters are Z=4,

[0012] The method for preparing the strontium borate nitrate nonlinear optical crystal adopts a high-temperature melt method or a hydrothermal method under vacuum sealing conditions to prepare the crystal:

[0013] The crystals were prepared by the high-temperature melt method under vacuum sealing conditions. The specific operation was carried out according to the following steps:

[0014] a. In a molar ratio of Sr:B:N=2-4:8-11:0.5-2, a Sr-containing compound, a B-containing compound and a N-containing compound are placed in a mortar and fully ground and mixed uniformly; the Sr-containing compound is Sr(NO3)2, SrCO3 or SrO, the B-containing compound is H3BO3 or B2O3 and the N-containing compound is Sr(NO3)2;

[0015] b. Place the mixture in step a into a 10 mm × 100 mm quartz tube and evacuate the tube to a vacuum degree of 1 × 10 -3 Pa, sealed under high temperature flame, placed in a muffle furnace, heated to 500-750°C at a rate of 10-50°C / h, kept constant at that temperature for 1-10 days, then cooled to room temperature at a rate of 0.1-2°C / h, opened the quartz tube, and thus a strontium borate nitrate nonlinear optical crystal was obtained;

[0016] The crystals were prepared by hydrothermal method, and the specific operation was carried out according to the following steps:

[0017] a. Mix the Sr-containing compound, the B-containing compound and the N-containing compound in a molar ratio of Sr:B:N=2-4:8-11:0.5-2, transfer the mixture into a polytetrafluoroethylene liner of a 25-100 mL autoclave, add 1.5-3 mL of deionized water and seal the autoclave; the Sr-containing compound is Sr(NO3)2 or SrO, the B-containing compound is H3BO3 or B2O3 and the N-containing compound is Sr(NO3)2;

[0018] b. Place the autoclave in step a in an oven, heat it to 170-220°C at a rate of 20-60°C / h, maintain the temperature for 3-15 days, then cool it to room temperature at a rate of 10-100°C / day, open the autoclave, and obtain strontium borate nitrate nonlinear optical crystals in the clarified solution.

[0019] The strontium borate nitrate nonlinear optical crystal is used in preparing a frequency doubling generator and an optical parametric oscillator.

[0020] The strontium borate nitrate nonlinear optical crystal of the present invention has a molecular formula of Sr3B9O 16 (NO3), its nonlinear optical effect is about 3 times that of KDP, the birefringence is 0.088@546nm, the space group is Cc, this crystal is simple to prepare, the growth cycle is short, the starting raw materials used are low in toxicity, and it is less toxic to the human body.

[0021] The preparation method of the strontium borate nitrate nonlinear optical crystal described in the present invention is a high-temperature melt method or a hydrothermal method under vacuum sealing conditions, that is, the starting materials are mixed according to a proportion, placed in a vacuum quartz tube or a polytetrafluoroethylene liner of a high-pressure reactor with a volume of 25-100 mL, and the strontium borate nitrate nonlinear optical crystal is obtained by constant temperature and cooling rate within a certain temperature range.

[0022] The Sr compound, B compound and N compound in the strontium borate nitrate nonlinear optical crystal of the present invention can adopt commercially available reagents and raw materials, the crystal growth method is simple and transparent, and has the advantages of simple operation method, fast growth rate and low cost.

[0023] The strontium borate nitrate nonlinear optical crystal has no special requirements on optical processing accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is the powder X-ray diffraction pattern of the present invention;

[0025] Figure 2 Sr3B9O of the present invention 16 (NO3) crystal structure diagram;

[0026] Figure 3 Sr3B9O of the present invention 16 (NO3) Photograph of micron-sized crystals under a polarizing microscope;

[0027] Figure 4 The working principle diagram of the nonlinear optical device made for the present invention includes: (1) a laser, (2) a fully converging lens, (3) a strontium borate nitrate nonlinear optical crystal, (4) a beam splitter prism, (5) a filter, and ω is the frequency of the refracted light, which is equal to the frequency of the incident light or twice the frequency of the incident light. DETAILED DESCRIPTION

[0028] The present invention is described in detail below with reference to the accompanying drawings and examples: The present invention is further described below with reference to the examples. It should be noted that the present invention is not limited to the examples given, and any improvements made on the basis of the present invention do not violate the spirit of the present invention. The raw materials or equipment used in the present invention, unless otherwise specified, are all commercially available.

[0029] Example 1

[0030] According to the chemical reaction formula 3Sr(NO3)2+4.5B2O3=Sr3B9O 16 The compound Sr3B9O was synthesized by vacuum sealing method using (NO3)+5NO2↑+1.25O2↑ 16 (NO3):

[0031] Sr(NO3)2 and B2O3 were mixed evenly according to the chemical formula, and placed in a Φ10mm quartz tube. The quartz tube was evacuated to a vacuum degree of 1×10 -3 Pa, flame sealed at high temperature, placed in a muffle furnace, heated to 500 ° C at a rate of 10 ° C / h, kept warm for 1 day, and slowly cooled to obtain the compound Sr3B9O 16 (NO3).

[0032] Example 2

[0033] According to the chemical reaction formula 3Sr(NO3)2+9H3BO3=Sr3B9O 16 The compound Sr3B9O was synthesized by vacuum sealing method using (NO3)+5NO2↑+13.5H2O↑+1.25O2↑ 16 (NO3):

[0034] Sr(NO3)2 and H3BO3 were mixed evenly according to the chemical formula, and placed in a Φ10mm quartz tube. The quartz tube was evacuated to a vacuum degree of 1×10 -3 Pa, flame sealed at high temperature, placed in a muffle furnace, heated to 550 ° C at a rate of 20 ° C / h, kept warm for 3 days, and slowly cooled to obtain the compound Sr3B9O 16 (NO3).

[0035] Example 3

[0036] According to the chemical reaction formula 2Sr(NO3)2+2SrCO3+4.5B2O3=Sr3B9O 16 The compound Sr3B9O was synthesized by vacuum sealing method using (NO3)+3NO2↑+CO2↑+0.75O2↑ 16 (NO3):

[0037] Sr(NO3)2, SrCO3 and B2O3 were mixed evenly according to the chemical formula, and placed in a Φ10mm quartz tube. The quartz tube was evacuated to a vacuum degree of 1×10 -3 Pa, flame sealed at high temperature, placed in a muffle furnace, heated to 600 ° C at a rate of 30 ° C / h, kept warm for 5 days, and slowly cooled to obtain the compound Sr3B9O 16 (NO3).

[0038] Example 4

[0039] According to the chemical reaction formula 2Sr(NO3)2+SrCO3+9H3BO3=Sr3B9O 16 The compound Sr3B9O was synthesized by vacuum sealing method using (NO3)+3NO2↑+CO2↑+13.5H2O↑+0.75O2↑ 16 (NO3):

[0040] Sr(NO3)2, SrCO3 and H3BO3 were mixed evenly according to the chemical formula, and placed in a Φ10mm quartz tube. The quartz tube was evacuated to a vacuum degree of 1×10 -3 Pa, flame sealed at high temperature, placed in a muffle furnace, heated to 650℃ at a rate of 35℃ / h, kept warm for 6 days, and slowly cooled to obtain the compound Sr3B9O 16 (NO3).

[0041] Example 5

[0042] According to the chemical reaction formula Sr(NO3)2+2SrCO3+4.5B2O3=Sr3B9O 16 The compound Sr3B9O was synthesized by vacuum sealing method using (NO3)+NO2↑+2CO2↑+0.25O2↑ 16 (NO3):

[0043] Sr(NO3)2, SrCO3 and B2O3 were mixed evenly according to the chemical formula, and placed in a Φ10mm quartz tube. The quartz tube was evacuated to a vacuum degree of 1×10 -3 Pa, flame sealed at high temperature, placed in a muffle furnace, heated to 700 ° C at a rate of 25 ° C / h, kept warm for 7 days, and slowly cooled to obtain the compound Sr3B9O 16 (NO3).

[0044] Example 6

[0045] According to the chemical reaction formula Sr(NO3)2+2SrCO3+8H3BO3=Sr3B9O 16 The compound Sr3B9O was synthesized by vacuum sealing method using (NO3)+NO2↑+2CO2↑+13.5H2O↑+0.25O2↑ 16 (NO3):

[0046] Sr(NO3)2, SrCO3 and H3BO3 were mixed evenly according to the chemical formula, and placed in a Φ10mm quartz tube. The quartz tube was evacuated to a vacuum degree of 1×10 -3 Pa, flame sealed at high temperature, placed in a muffle furnace, heated to 750 ° C at a rate of 10-50 ° C / h, kept warm for 8 days, and slowly cooled to obtain the compound Sr3B9O 16 (NO3).

[0047] Example 7

[0048] According to the chemical reaction formula 2Sr(NO3)2+SrO+4.5B2O3=Sr3B9O 16The compound Sr3B9O was synthesized by vacuum sealing method using (NO3)+3NO2↑+0.75O2↑ 16 (NO3):

[0049] Sr(NO3)2, SrO and B2O3 were mixed evenly according to the chemical formula, and placed in a Φ10 mm quartz tube. The quartz tube was evacuated to a vacuum degree of 1×10 -3 Pa, flame sealed at high temperature, placed in a muffle furnace, heated to 660℃ at a rate of 25℃ / h, kept warm for 10 days, and slowly cooled to obtain the compound Sr3B9O 16 (NO3).

[0050] Example 8

[0051] According to the chemical reaction formula 2Sr(NO3)2+SrO+9H3BO3=Sr3B9O 16 The compound Sr3B9O was synthesized by vacuum sealing method using (NO3)+3NO2↑+13.5H2O↑+0.75O2↑ 16 (NO3):

[0052] Sr(NO3)2, SrO and H3BO3 were mixed evenly according to the chemical formula, and placed in a Φ10mm quartz tube. The quartz tube was evacuated to a vacuum degree of 1×10 -3 Pa, flame sealed at high temperature, placed in a muffle furnace, heated to 590 ° C at a rate of 48 ° C / h, kept warm for 4 days, and slowly cooled to obtain the compound Sr3B9O 16 (NO3).

[0053] Example 9

[0054] According to the chemical reaction formula Sr(NO3)2+SrCO3+SrO+4.5B2O3=Sr3B9O 16 The compound Sr3B9O was synthesized by vacuum sealing method using (NO3)+NO2↑+CO2↑+0.25O2↑ 16 (NO3):

[0055] Sr(NO3)2, SrCO3, SrO and B2O3 were mixed evenly according to the chemical formula, and placed in a Φ10 mm quartz tube. The quartz tube was evacuated to a vacuum degree of 1×10 -3 Pa, flame sealed at high temperature, placed in a muffle furnace, heated to 730 ° C at a rate of 39 ° C / h, kept warm for 9 days, and slowly cooled to obtain the compound Sr3B9O 16 (NO3).

[0056] Example 10

[0057] According to the chemical reaction formula Sr(NO3)2+SrCO3+SrO+9H3BO3=Sr3B9O 16 The compound Sr3B9O was synthesized by vacuum sealing method using (NO3)+NO2↑+CO2↑+13.5H2O↑+0.25O2↑ 16 (NO3):

[0058] Sr(NO3)2, SrCO3, SrO and H3BO3 were mixed evenly according to the chemical formula, and placed in a Φ10mm quartz tube. The quartz tube was evacuated to a vacuum degree of 1×10 -3 Pa, flame sealed at high temperature, placed in a muffle furnace, heated to 620℃ at a rate of 18℃ / h, kept warm for 2 days, and slowly cooled to obtain the compound Sr3B9O 16 (NO3).

[0059] Example 11

[0060] According to the chemical reaction formula 3Sr(NO3)2+9H3BO3=Sr3B9O 16 (NO3)+5NO2↑+13.5H2O↑+1.25O2↑Sr3B9O was prepared by high temperature melt method under vacuum sealing conditions. 16 (NO3) nonlinear optical crystal, the specific operation is carried out according to the following steps:

[0061] a. Mix Sr(NO3)2 and H3BO3 evenly according to the chemical formula, place in a mortar and grind thoroughly to make the reactants evenly mixed;

[0062] b. Place the mixture in step a into a 10 mm quartz tube and evacuate the tube to a vacuum degree of 1 × 10 -3 Pa, flame sealed at high temperature, placed in a muffle furnace, heated to 550°C at a rate of 20°C / h, kept warm for 2 days, then cooled to room temperature at a rate of 0.5°C / h, opened the quartz tube, and obtained a strontium borate nitrate nonlinear optical crystal.

[0063] Example 12

[0064] According to the chemical reaction formula 2Sr(NO3)2+2SrCO3+4.5B2O3=Sr3B9O 16 (NO3)+3NO2↑+CO2↑+0.75O2↑Sr3B9O was prepared by high temperature melt method under vacuum sealing conditions. 16 (NO3) nonlinear optical crystal, the specific operation is carried out according to the following steps:

[0065] a. Mix Sr(NO3)2, SrCO3 and B2O3 according to the chemical formula, grind them thoroughly in a mortar to make the reactants evenly mixed;

[0066] b. Place the mixture in step a into a 10 mm quartz tube and evacuate the tube to a vacuum degree of 1 × 10 -3 Pa, flame sealed at high temperature, placed in a muffle furnace, heated to 580°C at a rate of 30°C / h, kept warm for 3 days, then cooled to room temperature at a rate of 0.7°C / h, opened the quartz tube, and obtained a strontium borate nitrate nonlinear optical crystal.

[0067] Example 13

[0068] According to the chemical reaction formula 2Sr(NO3)2+SrCO3+9H3BO3=Sr3B9O 16 (NO3)+3NO2↑+CO2↑+13.5H2O↑+0.75O2↑Sr3B9O was prepared by high temperature melt method under vacuum sealing conditions. 16 (NO3) nonlinear optical crystal, the specific operation is carried out according to the following steps:

[0069] a. Mix Sr(NO3)2, SrCO3 and H3BO3 according to the chemical formula, place them in a mortar and grind them thoroughly to make the reactants evenly mixed;

[0070] b. Place the mixture in step a into a 10 mm quartz tube and evacuate the tube to a vacuum degree of 1 × 10 -3 Pa, flame sealed at high temperature, placed in a muffle furnace, heated to 600°C at a rate of 15°C / h, kept warm for 4 days, then cooled to room temperature at a rate of 0.9°C / h, opened the quartz tube, and obtained a strontium borate nitrate nonlinear optical crystal.

[0071] Example 14

[0072] According to the chemical reaction formula Sr(NO3)2+2SrCO3+4.5B2O3=Sr3B9O 16 (NO3)+NO2↑+2CO2↑+0.25O2↑Sr3B9O was prepared by high temperature melt method under vacuum sealing conditions. 16 (NO3) nonlinear optical crystal, the specific operation is carried out according to the following steps:

[0073] a. Mix Sr(NO3)2, SrCO3 and B2O3 according to the chemical formula, grind them thoroughly in a mortar to make the reactants evenly mixed;

[0074] b. Place the mixture in step a into a 10 mm quartz tube and evacuate the tube to a vacuum degree of 1 × 10 -3Pa, flame sealed at high temperature, placed in a muffle furnace, heated to 750°C at a rate of 14°C / h, kept warm for 2 days, then cooled to room temperature at a rate of 0.1°C / h, opened the quartz tube, and obtained a strontium borate nitrate nonlinear optical crystal.

[0075] Example 15

[0076] According to the chemical reaction formula Sr(NO3)2+2SrCO3+8H3BO3=Sr3B9O 16 (NO3)+NO2↑+2CO2↑+13.5H2O↑+0.25O2↑Sr3B9O was prepared by high temperature melt method under vacuum sealing conditions. 16 (NO3) nonlinear optical crystal, the specific operation is carried out according to the following steps:

[0077] a. Mix Sr(NO3)2, SrCO3 and H3BO3 according to the chemical formula, place them in a mortar and grind them thoroughly to make the reactants evenly mixed;

[0078] b. Place the mixture in step a into a 10 mm quartz tube and evacuate the tube to a vacuum degree of 1 × 10 -3 Pa, flame sealed at high temperature, placed in a muffle furnace, heated to 620℃ at a rate of 32℃ / h, kept warm for 5 days, then cooled to room temperature at a rate of 1℃ / h, opened the quartz tube, and obtained strontium borate nitrate nonlinear optical crystal.

[0079] Example 16

[0080] According to the chemical reaction formula 2Sr(NO3)2+SrO+4.5B2O3=Sr3B9O 16 (NO3)+3NO2↑+0.75O2↑Sr3B9O was prepared by high temperature melt method under vacuum sealing conditions. 16 (NO3) nonlinear optical crystal, the specific operation is carried out according to the following steps:

[0081] a. Mix Sr(NO3)2, SrO and B2O3 evenly according to the chemical formula, place them in a mortar and grind them thoroughly to make the reactants evenly mixed;

[0082] b. Place the mixture in step a into a 10 mm quartz tube and evacuate the tube to a vacuum degree of 1 × 10 -3 Pa, flame sealed at high temperature, placed in a muffle furnace, heated to 700℃ at a rate of 50℃ / h, kept warm for 8 days, then cooled to room temperature at a rate of 1.5℃ / h, opened the quartz tube, and obtained a strontium borate nitrate nonlinear optical crystal.

[0083] Example 17

[0084] According to the chemical reaction formula 2Sr(NO3)2+SrO+9H3BO3=Sr3B9O 16 (NO3)+3NO2↑+13.5H2O↑+0.75O2↑Sr3B9O was prepared by high temperature melt method under vacuum sealing conditions. 16 (NO3) nonlinear optical crystal, the specific operation is carried out according to the following steps:

[0085] a. Mix Sr(NO3)2, SrO and H3BO3 evenly according to the chemical formula, place them in a mortar and grind them thoroughly to make the reactants evenly mixed;

[0086] b. Place the mixture in step a into a 10 mm quartz tube and evacuate the tube to a vacuum degree of 1 × 10 -3 Pa, flame sealed at high temperature, placed in a muffle furnace, heated to 720°C at a rate of 48°C / h, kept warm for 6 days, then cooled to room temperature at a rate of 1.8°C / h, opened the quartz tube, and obtained a strontium borate nitrate nonlinear optical crystal.

[0087] Example 18

[0088] According to the chemical reaction formula Sr(NO3)2+SrCO3+SrO+4.5B2O3=Sr3B9O 16 (NO3)+NO2↑+CO2↑+0.25O2↑Sr3B9O was prepared by high temperature melt method under vacuum sealing conditions. 16 (NO3) nonlinear optical crystal, the specific operation is carried out according to the following steps:

[0089] a. Mix Sr(NO3)2, SrCO3, SrO and B2O3 in the chemical formula and grind them thoroughly in a mortar to make the reactants evenly mixed;

[0090] b. Place the mixture in step a into a 10 mm quartz tube and evacuate the tube to a vacuum degree of 1 × 10 -3 Pa, flame sealed at high temperature, placed in a muffle furnace, heated to 750℃ at a rate of 50℃ / h, kept warm for 7 days, then cooled to room temperature at a rate of 2℃ / h, opened the quartz tube, and obtained a strontium borate nitrate nonlinear optical crystal.

[0091] Example 19

[0092] According to the chemical reaction formula Sr(NO3)2+SrCO3+SrO+9H3BO=Sr3B9O 16 (NO3)+NO2↑+CO2↑+13.5H2O↑+0.25O2↑Sr3B9O was prepared by high temperature melt method under vacuum sealing conditions. 16 (NO3) nonlinear optical crystal, the specific operation is carried out according to the following steps:

[0093] a. Mix Sr(NO3)2, SrCO3, SrO and H3BO3 according to the chemical formula, place them in a mortar and grind them thoroughly to make the reactants evenly mixed;

[0094] b. Place the mixture in step a into a 10 mm quartz tube and evacuate the tube to a vacuum degree of 1 × 10 -3 Pa, flame sealed at high temperature, placed in a muffle furnace, heated to 650℃ at a rate of 50℃ / h, kept warm for 10 days, then cooled to room temperature at a rate of 1.3℃ / h, opened the quartz tube, and obtained a strontium borate nitrate nonlinear optical crystal.

[0095] Example 20

[0096] According to the chemical reaction formula 3Sr(NO3)2+4.5B2O3=Sr3B9O 16 Preparation of Sr3B9O by hydrothermal method using (NO3)+5NO2↑+1.25O2↑ 16 (NO3) nonlinear optical crystal, the specific operation is carried out according to the following steps:

[0097] a. Mix Sr(NO3)2 and B2O3 evenly according to the chemical formula, transfer to the polytetrafluoroethylene liner of a 25 mL autoclave, add 1.5 mL of deionized water and tighten the autoclave;

[0098] b. Place the autoclave in step a in an oven, heat it to 180°C at a rate of 20°C / h, keep it constant for 4 days, then cool it to room temperature at a rate of 15°C / day, open the autoclave, and obtain strontium borate nitrate nonlinear optical crystals in the clarified solution.

[0099] Example 21

[0100] According to the chemical reaction formula 3Sr(NO3)2+9H3BO3=Sr3B9O 16 Sr3B9O was prepared by hydrothermal method using (NO3)+5NO2↑+13.5H2O↑+1.25O2↑ 16 (NO3) nonlinear optical crystal, the specific operation is carried out according to the following steps:

[0101] a. Mix Sr(NO3)2 and H3BO3 evenly according to the chemical formula, transfer to the polytetrafluoroethylene liner of a 25 mL autoclave, add 1.5 mL of deionized water and tighten the autoclave to seal.

[0102] b. Place the autoclave in step a in an oven, heat it to 210°C at a rate of 30°C / h, keep it constant for 10 days, then cool it to room temperature at a rate of 25°C / day, open the autoclave, and obtain strontium borate nitrate nonlinear optical crystals in the clarified solution.

[0103] Example 22

[0104] According to the chemical reaction formula 2Sr(NO3)2+SrO+4.5B2O3=Sr3B9O 16 Preparation of Sr3B9O by hydrothermal method using (NO3)+3NO2↑+0.75O2↑ 16 (NO3) nonlinear optical crystal, the specific operation is carried out according to the following steps:

[0105] a. Mix Sr(NO3)2, SrO and B2O3 evenly according to the chemical formula, transfer to the polytetrafluoroethylene liner of a 100 mL autoclave, add 3 mL of deionized water and tighten the autoclave to seal.

[0106] b. Place the autoclave in step a in an oven, raise the temperature to 190°C at a rate of 40°C / h, maintain the temperature for 11 days, then cool to room temperature at a rate of 35°C / day, open the autoclave, and obtain strontium borate nitrate nonlinear optical crystals in the clarified solution.

[0107] Example 23

[0108] According to the chemical reaction formula 2Sr(NO3)2+SrO+9H3BO3=Sr3B9O 16 Sr3B9O was prepared by hydrothermal method using (NO3)+3NO2↑+13.5H2O↑+0.75O2↑ 16 (NO3) nonlinear optical crystal, the specific operation is carried out according to the following steps:

[0109] a. Mix Sr(NO3)2, SrO and H3BO3 evenly according to the chemical formula, transfer to the polytetrafluoroethylene liner of a 100 mL autoclave, add 3 mL of deionized water and tighten the autoclave;

[0110] b. Place the autoclave in step a in an oven, raise the temperature to 205°C at a rate of 50°C / h, maintain the temperature for 7 days, then cool to room temperature at a rate of 45°C / day, open the autoclave, and obtain strontium borate nitrate nonlinear optical crystals in the clarified solution.

[0111] Example 24

[0112] Any of the strontium borate nitrate nonlinear optical crystals obtained in Examples 11-23 was prepared according to the attached Figure 4As shown, it is placed at position 3. At room temperature, using the 1064nm output of a Q-switched Nd:YAG laser as the light source, obvious 1064nm frequency-doubled green light output is observed, and the output intensity is about 3 times that of KDP under the same conditions.

[0113] Figure 4 As shown, an infrared beam with a wavelength of 1064nm emitted by a Q-switched Nd:YAG laser 1 is incident on a barium chloride fluoroborate nonlinear optical crystal through a condenser lens 2, generating green frequency-doubled light with a wavelength of 532nm. The output beam 4 contains infrared light with a wavelength of 1064nm and green light with a wavelength of 532nm, which is filtered out by a filter 5 to obtain frequency-doubled light with a wavelength of 532nm.

Claims

1. A compound strontium borate nitrate, characterized in that The chemical formula of this compound is Sr3B9O 16 (NO3), molecular weight 678.16, made in vacuum sealed tubes.

2. The method for preparing the compound strontium borate nitrate according to claim 1, wherein It is made by vacuum sealing method, and the specific operation is carried out according to the following steps: The Sr-containing compound, the B-containing compound and the N-containing compound were mixed evenly in a molar ratio of Sr:B:N=2-4:8-11:0.5-2, and placed in a quartz tube of Ø10 mm×100 mm. The quartz tube was evacuated to a vacuum degree of 1×10 −3 Pa, flame sealed at high temperature, placed in a muffle furnace, heated to 500-750 ° C at a rate of 10-50 ° C / h, kept at a constant temperature for 1-10 days, and slowly cooled to obtain the compound Sr3B9O 16 (NO3), wherein the Sr-containing compound is Sr(NO3)2, SrCO3 or SrO, the B-containing compound is H3BO3 or B2O3, and the N-containing compound is Sr(NO3)2.

3. A strontium borate nitrate nonlinear optical crystal, characterized in that The chemical formula of this crystal is Sr3B9O 16 (NO3), molecular weight is 678.16, crystal belongs to monoclinic system, space group is Cc , the unit cell parameters are a = 11.2574(9) Å, b = 6.6400(9) Å, c = 18.1027(13) Å, Z = 4, V = 1348.9(2) Å 3 .

4. The method for preparing the strontium borate nitrate nonlinear optical crystal according to claim 3, wherein Crystals are prepared using a high-temperature melt method or hydrothermal method under vacuum sealing conditions: The crystals were prepared by the high-temperature melt method under vacuum sealing conditions. The specific operation was carried out according to the following steps: a. In a molar ratio of Sr:B:N=2-4:8-11:0.5-2, a Sr-containing compound, a B-containing compound and a N-containing compound are placed in a mortar and fully ground and mixed uniformly; the Sr-containing compound is Sr(NO3)2, SrCO3 or SrO, the B-containing compound is H3BO3 or B2O3 and the N-containing compound is Sr(NO3)2; b. Place the mixture in step a into a 10 mm × 100 mm quartz tube and evacuate the tube to a vacuum degree of 1 × 10 −3 Pa, sealed under high temperature flame, placed in a muffle furnace, heated to 500-750°C at a rate of 10-50°C / h, kept constant at that temperature for 1-10 days, then cooled to room temperature at a rate of 0.1-2°C / h, opened the quartz tube, and thus a strontium borate nitrate nonlinear optical crystal was obtained; The crystals were prepared by hydrothermal method, and the specific operation was carried out according to the following steps: a. Mix the Sr-containing compound, the B-containing compound, and the N-containing compound in a molar ratio of Sr:B:N=2-4:8-11:0.5-2, transfer the mixture into a polytetrafluoroethylene liner of a 25-100 mL autoclave, add 1.5-3 mL of deionized water, and seal the autoclave tightly; the Sr-containing compound is Sr(NO3)2 or SrO, the B-containing compound is H3BO3 or B2O3, and the N-containing compound is Sr(NO3)2; b. Place the autoclave in step a in an oven, heat it to 170-220°C at a rate of 20-60°C / h, maintain the temperature for 3-15 days, then cool it to room temperature at a rate of 10-100°C / day, open the autoclave, and obtain strontium borate nitrate nonlinear optical crystals in the clarified solution.

5. Use of the strontium borate nitrate nonlinear optical crystal according to claim 3 in the preparation of a frequency doubling generator and an optical parametric oscillator.

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