Compound caesium sodium fluoborate and caesium sodium fluoborate nonlinear optical crystal, and preparation method and application of compound caesium sodium fluoborate nonlinear optical crystal

Abstract

The invention provides a compound cesium sodium fluoborate, a cesium sodium fluoborate nonlinear optical crystal and a preparation method and application thereof, the chemical formula of the compound is NaCs7 [B3O3F4 (OH)] 4 (H2O) 3, the molecular weight is 1701.16, and the compound is prepared by a room temperature solution method; the chemical formula of the crystal is NaCs7 [B3O3F4 (OH)] 4 (H2O) 3, the molecular weight is 1701.16, the crystal belongs to a monoclinic system, the space group is P21, the cell parameters are as follows: a is equal to 11.5864 (15), b is equal to 13.463 (2), c is equal to 12.5958 (19), alpha is equal to 90 degrees, beta is equal to 90 degrees, gamma is equal to 109.697 (5) degrees, the unit cell volume is 1849 (5) 3, the crystal is grown by adopting a room temperature solution method or a hydrothermal method, the chemical stability of the crystal is good, and the crystal can be used as a short-wavelength nonlinear optical crystal to be applied to an all-solid-state laser.

Description

Technical Field

[0001] The invention relates to a compound sodium cesium fluoroborate NaCs7[B3O3F4(OH)]4(H2O)3 and a sodium cesium fluoroborate NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal, a preparation method and an application thereof. Background Art

[0002] With the strong demand for short-wave laser sources in modern instruments such as 193nm lithography, micro-nano precision laser processing, and ultra-high energy resolution photoelectron spectrometers and photoelectron emission microscopes, the development of all-solid-state laser light sources has become a hot topic in the recent research of the international laser science community. In the development of all-solid-state short-wave ultraviolet laser light sources, short-wave nonlinear optical crystals are a very key component.

[0003] Due to its high energy and high beam quality, ultraviolet lasers have important applications in lithography, micromachining, optoelectronic devices and many other fields. Frequency conversion through nonlinear optical crystals is one of the most effective methods to output ultraviolet lasers. So far, the short-wavelength nonlinear optical crystals currently in practical use are β-BaB2O4, LiB3O5 and KBe2BO3F2 crystals invented by Chinese scientists, but due to the limitations of their crystal structure and some performance, they are still unable to be truly industrialized to meet the needs of scientific and technological development. Among them, the birefringence of β-BaB2O4 crystal is too large, the acceptance angle that meets the phase matching condition is small, and the walk-off angle is large, resulting in low frequency conversion efficiency and poor spot quality when realizing laser output; the birefringence of LiB3O5 crystal is too small, and the shortest phase matching wavelength is only 276nm, and it is impossible to output 266nm or shorter wavelength lasers through direct frequency doubling; KBe2BO3F2 crystal is restricted by intrinsic defects (weak interlayer forces in the structure), the layered growth habit of the crystal is very serious, and it is not easy to grow large-sized crystals. Therefore, it is of great significance and practical value to prepare and synthesize new short-wavelength nonlinear optical crystal materials with excellent comprehensive performance. Summary of the invention

[0004] The present invention aims to provide a compound of sodium cesium fluoroborate, the chemical formula of which is NaCs7[B3O3F4(OH)]4(H2O)3, the molecular weight of which is 1701.16, and which is prepared by a room temperature solution method.

[0005] Another object of the present invention is to provide a sodium cesium fluoroborate NaCs7[(B3O3F4(OH)]4(H2O)3 nonlinear optical crystal, with a molecular weight of 161.06, belonging to the monoclinic system, a space group of P21, unit cell parameters of a=11.5864(15), b=13.463(2), c=12.5958(19), α=90°, β=90°, γ=109.697(5)°, and a unit cell volume of

[0006] Another object of the present invention is to provide a method for preparing sodium cesium fluoroborate NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal, which adopts room temperature solution method or hydrothermal method to grow crystal.

[0007] Another object of the present invention is to provide the use of sodium cesium fluoroborate NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal.

[0008] The compound of the invention is cesium sodium fluoroborate, the chemical formula of the compound is NaCs7[B3O3F4(OH)]4(H2O)3, the molecular weight is 1701.16, and the compound is prepared by a room temperature solution method.

[0009] The preparation method of the compound sodium cesium fluoroborate adopts a room temperature solution method, and the specific operation is carried out according to the following steps: Na-containing compounds, Cs-containing compounds and B and F-containing compounds are evenly mixed according to a molar ratio of Na:Cs:B:F=1:7:12:16, and put into a clean plastic container, add 20-100mL deionized water, and then ultrasonicate to fully mix and dissolve, filter with filter paper to obtain a mixed solution, and then seal with plastic wrap, poke a number of small holes in the seal, and stand at a temperature of 40-50°C for 5-20 days to obtain the compound NaCs7[B3O3F4(OH)]4(H2O)3, wherein the Na-containing compound is NaHF2, NaF, Na2CO3, NaHCO3, and NaOH; the Cs-containing compound is CsHF2, CsF, Cs2CO3, and CsHCO3; the B-containing compound is H3BO3, HBO2, and B2O3; and the F-containing compound is HF and HBF4.

[0010] A sodium cesium fluoroborate nonlinear optical crystal, the chemical formula of the crystal is NaCs7[B3O3F4(OH)]4(H2O)3, the molecular weight is 1701.16, the crystal belongs to the monoclinic system, the space group is P21, the unit cell parameters are a=11.5864(15), b=13.463(2), c=12.5958(19), α=90°, β=90°, γ=109.697(5)°, and the unit cell volume is

[0011] The method for preparing the sodium cesium fluoroborate nonlinear optical crystal adopts a room temperature solution method or a hydrothermal method to grow the crystal;

[0012] The room temperature solution method for growing sodium cesium fluoroborate nonlinear optical crystal is specifically performed in the following steps:

[0013] a. Mix the Na-containing compound, Cs-containing compound, B-containing compound and F-containing compound in a molar ratio of Na:Cs:B:F=1:7:12:16, put them into a clean plastic container, add 20-100 mL of deionized water, perform ultrasonic treatment to fully mix and dissolve them, and filter to obtain a mixed solution; the Na-containing compound is NaHF2, NaF, Na2CO3, NaHCO3 or NaOH; the Cs-containing compound is CsHF2, CsF, Cs2CO3 or CsHCO3; the B-containing compound is H3BO3, HBO2 or B2O3; the F-containing compound is HF or HBF4;

[0014] b. Place the mixed solution obtained in step a in a clean plastic container, seal it with weighing paper, place it in a static environment without shaking, pollution, or air convection, pierce a number of small holes in the seal to adjust the evaporation rate of water in the aqueous solution, and leave it at a temperature of 40-50° C. for 5-20 days;

[0015] c. Waiting for the solution in step b to grow crystal particles at the bottom of the container until the size of the crystal particles no longer changes significantly, thereby obtaining seed crystals;

[0016] d. Select the seed crystal with better quality in step c, suspend it in the mixed solution prepared in step b, and let it stand and grow for 10-30 days at a temperature of 40-50° C. to obtain NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal;

[0017] The hydrothermal method for growing sodium cesium fluoroborate nonlinear optical crystal is specifically performed in the following steps:

[0018] a. In a molar ratio of Na:Cs:B:F=1:7:12:16, place a Na-containing compound, a Cs-containing compound, a B-containing compound and a F-containing compound in a polytetrafluoroethylene beaker and mix them evenly, put them into a clean plastic container, add 20-65 mL of water, stir and mix evenly, and filter to obtain a mixed solution, wherein the Na-containing compound is NaHF2, NaF, Na2CO3, NaHCO3 or NaOH; the Cs-containing compound is CsHF2, CsF, Cs2CO3 or CsHCO3; the B-containing compound is H3BO3, HBO2 or B2O3; the F-containing compound is HF or HBF4.

[0019] b. Transfer the mixed solution obtained in step a into the polytetrafluoroethylene liner of a 23 ml high-pressure reactor, add deionized water as a solvent, and tighten and seal the mouth of the reactor;

[0020] c. Place the autoclave in step b in a thermostat and heat the temperature to 220°C at a rate of 20°C / h, keep the temperature constant for 24 hours, and then cool it down to room temperature at a rate of 2°C / h;

[0021] d. Open the high-pressure reactor and obtain millimeter-sized large-sized NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystals in the colorless clear solution.

[0022] The sodium cesium fluoroborate nonlinear optical crystal is used in preparing the 1064nm fundamental frequency light output by the Nd:YAG laser for double-frequency and triple-frequency harmonic light output.

[0023] The sodium cesium fluoroborate nonlinear optical crystal is used in preparing short-wavelength frequency-doubled light outputs of 266nm and 355nm.

[0024] The sodium cesium fluoroborate nonlinear optical crystal is used in preparing a frequency doubling generator, an up or down frequency converter or an optical parametric oscillator.

[0025] In the preparation method of sodium cesium fluoroborate nonlinear optical crystal of the present invention, the container used in the preparation process is a plastic cup, and the inner lining is a hydrothermal kettle lined with polytetrafluoroethylene or a stainless steel lining equipped with a platinum sleeve. When using a plastic cup as a container, the container must be cleaned with acid first, then rinsed with deionized water, and dried.

[0026] The method for preparing sodium cesium fluoroborate nonlinear optical crystals of the present invention is adopted to obtain millimeter-sized NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystals. By using a large-sized container and extending the growth period of the crystal, a corresponding large-sized nonlinear optical crystal NaCs7[B3O3F4(OH)]4(H2O)3 can be obtained. During the growth of the NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal, the crystal is easy to grow, transparent and without wrapping, and has the advantages of fast growth speed, low cost, and easy acquisition of large-sized crystals.

[0027] By adopting the preparation method of sodium cesium fluoroborate nonlinear optical crystal described in the present invention, a large-sized NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal is obtained. According to the crystallographic data of the crystal, the crystal blank is oriented, the crystal is cut according to the required angle, thickness and cross-sectional size, and the light-transmitting surface of the crystal is polished. Then, the crystal can be used as a nonlinear optical device. The NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal has the advantages of stable physicochemical properties, not easy to deliquesce, easy to process and preserve, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is the powder XRD spectrum of the compound NaCs7[B3O3F4(OH)]4(H2O)3 of the present invention;

[0029] Figure 2 It is a structural diagram of the NaCs7[B3O3F4(OH)]4(H2O)3 crystal of the present invention;

[0030] Figure 3 This is a working principle diagram of a nonlinear optical device made of NaCs7[B3O3F4(OH)]4(H2O)3 crystal of the present invention, wherein 1 is a laser, 2 is an emitted light beam, 3 is a NaCs7[B3O3F4(OH)]4(H2O)3 crystal, 4 is an output light beam, and 5 is a filter. DETAILED DESCRIPTION

[0031] The present invention is further described below in conjunction with the examples. It should be noted that the following examples cannot be used to limit the scope of protection of the present invention, 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.

[0032] Example 1

[0033] According to the reaction formula: NaHF2+7CsHCO3+12H3BO3+14HF→NaCs7[B3O3F4(OH)]4(H2O)3+24H2O+7CO2, the compound NaCs7[B3O3F4(OH)]4(H2O)3 was synthesized by room temperature solution method:

[0034] NaHF2, CsHCO3, H3BO3 and HF were mixed evenly in a molar ratio of 1:7:12:14, put into a clean plastic container, added with 80 mL of deionized water, and then ultrasonicated to fully mix and dissolve, filtered to obtain a mixed solution, and then sealed with plastic wrap, pierced a number of small holes in the seal, and allowed to stand at 45°C for 15 days to obtain a polycrystalline powder of the compound NaCs7[B3O3F4(OH)]4(H2O)3.

[0035] Example 2

[0036] According to the reaction formula: NaHF2+7CsF+6B2O3+7HF+H2O→NaCs7[B3O3F4(OH)]4(H2O)3, the compound NaCs7[B3O3F4(OH)]4(H2O)3 was synthesized by room temperature solution method:

[0037] NaHF2, CsF, B2O3 and HF were mixed evenly in a molar ratio of 1:7:6:7, put into a clean plastic container, 80 mL of deionized water was added, and then ultrasonic treatment was performed to fully mix and dissolve. The mixed solution was filtered to obtain a mixed solution, and then the container was sealed with plastic wrap, and a number of small holes were pierced in the seal. The container was allowed to stand at 45°C for 15 days to obtain a polycrystalline powder of the compound NaCs7[B3O3F4(OH)]4(H2O)3.

[0038] Example 3

[0039] According to the reaction formula: 11NaHF2+14Cs2CO3+48H3BO3+42HF→4NaCs7[B3O3F4(OH)]4(H2O)3+7CO2+7NaHCO3+75H2O, the compound NaCs7[B3O3F4(OH)]4(H2O)3 was synthesized by room temperature solution method:

[0040] NaHF2, Cs2CO3, H3BO3 and HF were mixed evenly in a molar ratio of 11:14:48:42, and put into a clean plastic container. 80 mL of deionized water was added, and then ultrasonic treatment was performed to fully mix and dissolve. The solution was filtered to obtain a mixed solution, and then the container was sealed with plastic wrap. Several small holes were pierced in the seal, and the container was allowed to stand at 45°C for 15 days to obtain a polycrystalline powder of the compound NaCs7[B3O3F4(OH)]4(H2O)3.

[0041] Example 4

[0042] According to the reaction formula: NaHF2+7CsHF2+12H3BO3→NaCs7[B3O3F4(OH)]4(H2O)3+17H2O, the compound NaCs7[B3O3F4(OH)]4(H2O)3 was synthesized by room temperature solution method:

[0043] NaHF2, CsHF2 and H3BO3 were mixed evenly in a molar ratio of 1:7:12, put into a clean plastic container, and 80 mL of deionized water was added. The mixture was then ultrasonically treated to fully mix and dissolve. The mixture was filtered to obtain a mixed solution. The mixture was then sealed with plastic wrap, and a number of small holes were pierced in the seal. The mixture was allowed to stand at 45°C for 15 days to obtain a polycrystalline powder of the compound NaCs7[B3O3F4(OH)]4(H2O)3.

[0044] Example 5

[0045] According to the reaction formula: 8NaHF2+7CsHCO3+12H3BO3→NaCs7[B3O3F4(OH)]4(H2O)3+17H2O+7NaHCO3, the compound NaCs7[(B3O3F4(OH)]4(H2O)3 was synthesized by room temperature solution method:

[0046] Mix NaHF2, CsHCO3 and H3BO3 in a molar ratio of 8:7:12 in a clean plastic container, add 80 mL of deionized water, and then treat with ultrasound to fully mix and dissolve. Filter to obtain a mixed solution, seal the container with plastic wrap, poke a number of small holes in the seal, and let it stand at 45°C for 15 days to obtain a polycrystalline powder of the compound NaCs7[(B3O3F4(OH)]4(H2O)3.

[0047] Example 6

[0048] According to the reaction formula: NaHF2+7CsHCO3+6B2O3+14HF→NaCs7[B3O3F4(OH)]4(H2O)3+7CO2+6H2O, the compound NaCs7[B3O3F4(OH)]4(H2O)3 was synthesized by room temperature solution method:

[0049] NaF, CsHCO3, B2O3 and HF were mixed evenly in a molar ratio of 1:7:6:14, put into a clean plastic container, added with 20 mL of deionized water, and then ultrasonicated to fully mix and dissolve, filtered to obtain a mixed solution, and then sealed with plastic wrap, pierced a number of small holes in the seal, and allowed to stand at 50°C for 5 days to obtain a polycrystalline powder of the compound NaCs7[B3O3F4(OH)]4(H2O)3.

[0050] Example 7

[0051] According to the reaction formula: NaHF2+7CsF+12HBO2+7HF→NaCs7[B3O3F4(OH)]4(H2O)3+5H2O, the compound NaCs7[B3O3F4(OH)]4(H2O)3 was synthesized by room temperature solution method:

[0052] NaHF2, CsF, HBO2 and HF were mixed evenly in a molar ratio of 1:7:12:7, put into a clean plastic container, added with 50 mL of deionized water, and then ultrasonicated to fully mix and dissolve, filtered to obtain a mixed solution, and then sealed with plastic wrap, pierced a number of small holes in the seal, and allowed to stand at 40°C for 10 days to obtain a polycrystalline powder of the compound NaCs7[B3O3F4(OH)]4(H2O)3.

[0053] Example 8

[0054] According to the reaction formula: NaF+7CsF+12H3BO3+8HF→NaCs7[B3O3F4(OH)]4(H2O)3+17H2O, the compound NaCs7[B3O3F4(OH)]4(H2O)3 was synthesized by room temperature solution method:

[0055] NaF, CsF, H3BO3 and HF were mixed evenly in a molar ratio of 1:7:12:8, put into a clean plastic container, added with 80 mL of deionized water, and then ultrasonicated to fully mix and dissolve, filtered to obtain a mixed solution, and then sealed with plastic wrap, pierced a number of small holes in the seal, and allowed to stand at 45°C for 15 days to obtain a polycrystalline powder of the compound NaCs7[B3O3F4(OH)]4(H2O)3.

[0056] Example 9

[0057] According to the reaction formula: NaF+7CsF+6B2O3+8HF→NaCs7[B3O3F4(OH)]4(H2O)3+H2O, the compound NaCs7[B3O3F4(OH)]4(H2O)3 was synthesized by room temperature solution method:

[0058] NaF, CsF, B2O3 and HF were mixed evenly in a molar ratio of 1:7:6:8, put into a clean plastic container, added with 100 mL of deionized water, and then ultrasonicated to fully mix and dissolve, filtered to obtain a mixed solution, and then sealed with plastic wrap, pierced a number of small holes in the seal, and allowed to stand at 40°C for 20 days to obtain a polycrystalline powder of the compound NaCs7[B3O3F4(OH)]4(H2O)3.

[0059] Example 10

[0060] According to the reaction formula: NaF+7CsF+12HBO2+8HF→NaCs7[B3O3F4(OH)]4(H2O)3+5H2O, the compound NaCs7[B3O3F4(OH)]4(H2O)3 was synthesized by room temperature solution method:

[0061] NaF, CsF, HBO2 and HF were mixed evenly in a molar ratio of 1:7:12:8, put into a clean plastic container, added with 70 mL of deionized water, and then ultrasonicated to fully mix and dissolve, filtered to obtain a mixed solution, and then sealed with plastic wrap, pierced a number of small holes in the seal, and allowed to stand at 40°C for 18 days to obtain a polycrystalline powder of the compound NaCs7[B3O3F4(OH)]4(H2O)3.

[0062] Embodiment 11

[0063] According to the reaction formula: NaF+7CsF+10H3BO3+2HBF4→NaCs7[B3O3F4(OH)]4(H2O)3+11H2O, the compound NaCs7[B3O3F4(OH)]4(H2O)3 was synthesized by room temperature solution method:

[0064] NaF, CsF, H3BO3 and HBF4 were mixed evenly in a molar ratio of 1:7:10:2, put into a clean plastic container, added with 70 mL of deionized water, and then ultrasonicated to fully mix and dissolve, filtered to obtain a mixed solution, and then sealed with plastic wrap, pierced a number of small holes in the seal, and allowed to stand at 40°C for 18 days to obtain a polycrystalline powder of the compound NaCs7[B3O3F4(OH)]4(H2O)3.

[0065] Example 12

[0066] According to the reaction formula: 8NaOH+56CsF+39H3BO3+18HBF4+27H2O→8NaCs7[B3O3F4(OH)]4(H2O)3, NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal was grown by room temperature aqueous solution method:

[0067] a. Mix NaOH, CsF, H3BO3 and HBF4 evenly in a molar ratio of 8:56:39:18, put them into a clean plastic container, add 20 mL of deionized water, and then perform ultrasonic treatment to fully mix and dissolve them, and filter to obtain a mixed solution;

[0068] b. Place the mixed solution obtained in step a in a clean plastic container, seal it with weighing paper, place it in a static environment without shaking, pollution, or air convection, pierce several small holes in the seal to adjust the evaporation rate of water in the aqueous solution, and leave it at 40° C. for 20 days;

[0069] c. Waiting for the solution in step b to grow crystal particles at the bottom of the container until the size of the crystal particles no longer changes significantly, thereby obtaining seed crystals;

[0070] d. Select the seed crystal with better quality in step c, suspend it in the mixed solution prepared in step b, and let it stand and grow for 30 days at 40°C to obtain a 4mm×3mm×1mm NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal.

[0071] Embodiment 18

[0072] According to the reaction formula: 4NaOH+28CsF+39HBO2+9HBF4→4NaCs7[B3O3F4(OH)]4(H2O)3+7H2O, NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal was grown by room temperature aqueous solution method:

[0073] a. Mix NaOH, CsF, HBO2 and HBF4 evenly in a molar ratio of 4:28:39:9, put them into a clean plastic container, add 50 mL of deionized water, and then treat with ultrasound to fully mix and dissolve them, filter, and obtain a mixed solution;

[0074] b. Place the mixed solution obtained in step a in a clean plastic container, seal it with weighing paper, place it in a static environment without shaking, pollution, or air convection, pierce several small holes in the seal to adjust the evaporation rate of water in the aqueous solution, and leave it at 42° C. for 10 days;

[0075] c. Waiting for the solution in step b to grow crystal particles at the bottom of the container until the size of the crystal particles no longer changes significantly, thereby obtaining seed crystals;

[0076] d. Select the seed crystal with better quality in step c, suspend it in the mixed solution prepared in step b, and let it stand and grow for 10 days at a temperature of 42°C to obtain a 4mm×2mm×2mm NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal.

[0077] Embodiment 19

[0078] According to the reaction formula: 4NaOH+28CsF+39H3BO3+9HBF4→4NaCs7[B3O3F4(OH)]4(H2O)3+45H2O, NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal was grown by room temperature aqueous solution method:

[0079] a. Mix NaOH, CsF, H3BO3 and HBF4 in a molar ratio of 4:28:39:9, put them into a clean plastic container, add 80 mL of deionized water, and then treat with ultrasound to fully mix and dissolve them, filter, and obtain a mixed solution;

[0080] b. Place the mixed solution obtained in step a in a clean plastic container, seal it with weighing paper, place it in a static environment without shaking, pollution, or air convection, pierce several small holes in the seal to adjust the evaporation rate of water in the aqueous solution, and leave it at 50° C. for 5 days;

[0081] c. Waiting for the solution in step b to grow crystal particles at the bottom of the container until the size of the crystal particles no longer changes significantly, thereby obtaining seed crystals;

[0082] d. Select the seed crystal with better quality in step c, suspend it in the mixed solution prepared in step b, and let it stand and grow for 10 days at a temperature of 50°C to obtain a 3mm×2mm×1mm NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal.

[0083] Embodiment 20

[0084] According to the reaction formula: Na2CO3+14CsF+24H3BO3+18HF→2NaCs7[B3O3F4(OH)]4(H2O)3+35H2O+CO2, NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal was grown by room temperature aqueous solution method:

[0085] a. Mix Na2CO3, CsF, H3BO3 and HF in a molar ratio of 1:14:24:18, put them into a clean plastic container, add 100 mL of deionized water, and then treat with ultrasound to fully mix and dissolve them, and filter with filter paper to obtain a mixed solution.

[0086] b. Place the mixed solution obtained in step a in a clean plastic container, seal it with weighing paper, place it in a static environment without shaking, pollution, or air convection, pierce several small holes in the seal to adjust the evaporation rate of water in the aqueous solution, and let it stand at 40-50° C. for 5-20 days;

[0087] c. Waiting for the solution in step b to grow crystal particles at the bottom of the container until the size of the crystal particles no longer changes significantly, thereby obtaining seed crystals;

[0088] d. Select the seed crystal with better quality in step c, suspend it in the mixed solution prepared in step b, and let it stand and grow at a temperature of 40-50°C for 10-30 days to obtain a 4mm×3mm×3mm NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal.

[0089] Embodiment 21

[0090] According to the reaction formula: Na2CO3+14CsF+24HBO2+18HF→2NaCs7[B3O3F4(OH)]4(H2O)3+11H2O+CO2, the room temperature solution method is used to grow NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal:

[0091] a. Mix Na2CO3, CsF, HBO2 and HF in a molar ratio of 1:14:24:18, put them into a clean plastic container, add 30 mL of deionized water, and then treat with ultrasonic to fully mix and dissolve them, filter and obtain a mixed solution;

[0092] b. Place the mixed solution obtained in step a in a clean plastic container, seal it with weighing paper, place it in a static environment without shaking, pollution, or air convection, pierce several small holes in the seal to adjust the evaporation rate of water in the aqueous solution, and leave it at 45° C. for 15 days;

[0093] c. Waiting for the solution in step b to grow crystal particles at the bottom of the container until the size of the crystal particles no longer changes significantly, thereby obtaining seed crystals;

[0094] d. Select the seed crystal with better quality in step c, suspend it in the mixed solution prepared in step b, and let it stand and grow at 45°C for 20 days to obtain a 3mm×2mm×1mm NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal.

[0095] Embodiment 22

[0096] According to the reaction formula: Na2CO3+14CsF+12B2O3+18HF+H2O→2NaCs7[B3O3F4(OH)]4(H2O)3, the room temperature solution method was used to grow NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal:

[0097] a. Mix Na2CO3, Cs, B2O3 and HF in a molar ratio of 1:14:12:18, put them into a clean plastic container, add 100 mL of deionized water, and then treat with ultrasonic to fully mix and dissolve, filter to obtain a mixed solution;

[0098] b. Place the mixed solution obtained in step a in a clean plastic container, seal it with weighing paper, place it in a static environment without shaking, pollution, or air convection, pierce several small holes in the seal to adjust the evaporation rate of water in the aqueous solution, and leave it at 46° C. for 17 days;

[0099] c. Waiting for the solution in step b to grow crystal particles at the bottom of the container until the size of the crystal particles no longer changes significantly, thereby obtaining seed crystals;

[0100] d. Select the seed crystal with better quality in step c, suspend it in the mixed solution prepared in step b, and let it grow at 46°C for 22 days to obtain a 4mm×2mm×2mm NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal.

[0101] Embodiment 23

[0102] According to the reaction formula: 2Na2CO3+28CsF+39H3BO3+9HBF4→4NaCs7[B3O3F4(OH)]4(H2O)3+43H2O+CO2, NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal was grown by room temperature solution method:

[0103] a. Mix Na2CO3, CsF, H3BO3 and HBF4 evenly in a molar ratio of 2:28:39:9, put them into a clean plastic container, add 80 mL of deionized water, and then ultrasonicate them to fully mix and dissolve them, filter them, and obtain a mixed solution;

[0104] b. Place the mixed solution obtained in step a in a clean plastic container, seal it with weighing paper, place it in a static environment without shaking, pollution, or air convection, pierce several small holes in the seal to adjust the evaporation rate of water in the aqueous solution, and leave it at 48° C. for 18 days;

[0105] c. Waiting for the solution in step b to grow crystal particles at the bottom of the container until the size of the crystal particles no longer changes significantly, thereby obtaining seed crystals;

[0106] d. Select the seed crystal with better quality in step c, suspend it in the mixed solution prepared in step b, and let it grow at 48°C for 28 days to obtain a 3mm×2mm×2mm NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal.

[0107] Embodiment 24

[0108] According to the reaction formula: 2Na2CO3+28CsF+39HBO2+9HBF4→4NaCs7[B3O3F4(OH)]4(H2O)3+4H2O+2CO2, NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal was grown by room temperature solution method:

[0109] a. Mix Na2CO3, CsF, HBO2 and HBF4 evenly in a molar ratio of 2:28:39:9, put them into a clean plastic container, add 30 mL of deionized water, and then ultrasonicate them to fully mix and dissolve them, filter them, and obtain a mixed solution;

[0110] b. Place the mixed solution obtained in step a in a clean plastic container, seal it with weighing paper, place it in a static environment without shaking, pollution, or air convection, pierce several small holes in the seal to adjust the evaporation rate of water in the aqueous solution, and leave it at 43° C. for 8 days;

[0111] c. Waiting for the solution in step b to grow crystal particles at the bottom of the container until the size of the crystal particles no longer changes significantly, thereby obtaining seed crystals;

[0112] d. Select the seed crystal with better quality in step c, suspend it in the mixed solution prepared in step b, and let it grow at 43°C for 12 days to obtain a 4mm×3mm×3mm NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal.

[0113] Embodiment 25

[0114] According to the reaction formula: 4Na2CO3+56CsF+39B2O3+18HBF4+31H2O→8NaCs7[B3O3F4(OH)]4(H2O)3+4CO2, NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal was grown by room temperature solution method:

[0115] a. Mix Na2CO3, CsF, B2O3 and HBF4 evenly in a molar ratio of 4:56:39:18, put them into a clean plastic container, add 40 mL of deionized water, and then ultrasonicate them to fully mix and dissolve them, filter them, and obtain a mixed solution;

[0116] b. Place the mixed solution obtained in step a in a clean plastic container, seal it with weighing paper, place it in a static environment without shaking, pollution, or air convection, pierce several small holes in the seal to adjust the evaporation rate of water in the aqueous solution, and leave it at 46° C. for 11 days;

[0117] c. Waiting for the solution in step b to grow crystal particles at the bottom of the container until the size of the crystal particles no longer changes significantly, thereby obtaining seed crystals;

[0118] d. Select the seed crystal with better quality in step c, suspend it in the mixed solution prepared in step b, and let it stand and grow for 26 days at a temperature of 46°C to obtain a 3mm×2mm×2mm NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal.

[0119] Embodiment 26

[0120] According to the reaction formula: NaHCO3+7CsF+12H3BO3+9HF→NaCs7[B3O3F4(OH)]4(H2O)3+18H2O+CO2, the hydrothermal method is used to grow NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal:

[0121] a. Mix NaHCO3, CsF, H3BO3 and HF in a polytetrafluoroethylene beaker in a molar ratio of 1:7:12:9, put them into a clean plastic container, add 20 mL of water, stir and mix them evenly to obtain a mixed solution, and filter them with filter paper to obtain a mixed solution;

[0122] b. Transfer the mixed solution obtained in step a into the polytetrafluoroethylene liner of a 23 ml high-pressure reactor, add deionized water as a solvent, and tighten and seal the mouth of the reactor;

[0123] c. Place the autoclave in step b in a thermostat and heat the temperature to 220°C at a rate of 20°C / h, keep the temperature constant for 24 hours, and then cool it down to room temperature at a rate of 2°C / h;

[0124] d. Open the high-pressure reactor and obtain a 0.7 mm × 0.4 mm × 0.3 mm NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal in a colorless clear solution.

[0125] Embodiment 27

[0126] According to the reaction formula: NaHCO3+7CsHF2+12H3BO3+2HF→NaCs7[B3O3F4(OH)]4(H2O)3+18H2O+CO2, the hydrothermal method is used to grow NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal:

[0127] a. Place NaHCO3, CsHF2, H3BO3 and HF in a polytetrafluoroethylene beaker in a molar ratio of 1:7:12:2 and mix them evenly. Place them in a clean plastic container, add 25 mL of water, stir and mix evenly to obtain a mixed solution, and filter with filter paper to obtain a mixed solution.

[0128] b. Transfer the mixed solution obtained in step a into the polytetrafluoroethylene liner of a 23 ml high-pressure reactor, add deionized water as a solvent, and tighten and seal the mouth of the reactor;

[0129] c. Place the autoclave in step b in a thermostat and heat the temperature to 220°C at a rate of 20°C / h, keep the temperature constant for 24 hours, and then cool it down to room temperature at a rate of 2°C / h;

[0130] d. Open the high-pressure reactor and obtain a 0.9 mm × 0.5 mm × 0.4 mm NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal in a colorless clear solution.

[0131] Embodiment 28

[0132] Reaction formula: 2NaHCO3+7Cs2CO3+24H3BO3+32HF→2NaCs7[B3O3F4(OH)]4(H2O)3+43H2O+9CO2. The hydrothermal method is used to grow NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal:

[0133] a. Mix NaHCO3, Cs2CO3, H3BO3 and HF in a polytetrafluoroethylene beaker in a molar ratio of 2:7:24:32, put them into a clean plastic container, add 40 mL of water, stir and mix them evenly to obtain a mixed solution, and filter them with filter paper to obtain a mixed solution;

[0134] b. Transfer the mixed solution obtained in step a into the polytetrafluoroethylene liner of a 23 ml high-pressure reactor, add deionized water as a solvent, and tighten and seal the mouth of the reactor;

[0135] c. Place the autoclave in step b in a thermostat and heat the temperature to 220°C at a rate of 20°C / h, keep the temperature constant for 24 hours, and then cool it down to room temperature at a rate of 2°C / h;

[0136] d. Open the high-pressure reactor and obtain a 1 mm × 0.7 mm × 0.5 mm NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal in a colorless clear solution.

[0137] Embodiment 29

[0138] According to the reaction formula: NaHCO3+7CsHCO3+12H3BO3+16HF→NaCs7[B3O3F4(OH)]4(H2O)3+25H2O+8CO2, the hydrothermal method is used to grow NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal:

[0139] a. Mix NaHCO3, CsHCO3, H3BO3 and HF in a polytetrafluoroethylene beaker in a molar ratio of 1:7:12:16, put them into a clean plastic container, add 45 mL of water, stir and mix them evenly to obtain a mixed solution, and filter them with filter paper to obtain a mixed solution;

[0140] b. Transfer the mixed solution obtained in step a into the polytetrafluoroethylene liner of a 23 ml high-pressure reactor, add deionized water as a solvent, and tighten and seal the mouth of the reactor;

[0141] c. Place the autoclave in step b in a thermostat and heat the temperature to 220°C at a rate of 20°C / h, keep the temperature constant for 24 hours, and then cool it down to room temperature at a rate of 2°C / h;

[0142] d. Open the high-pressure reactor and obtain a 1 mm × 0.7 mm × 0.6 mm NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal in a colorless clear solution.

[0143] Embodiment 30

[0144] Any NaCs7[B3O3F4(OH)]4(H2O)3 crystal obtained in Examples 12-29 is processed in a matching direction, and the attached Figure 3 As shown, it is placed at position 3. At room temperature, a Q-switched Nd:YAG laser is used as the light source. The incident wavelength is 1064nm. The infrared light beam 2 with a wavelength of 1064nm emitted by the Q-switched Nd:YAG laser 1 is incident on the NaCs7[B3O3F4(OH)]4(H2O)3 single crystal 3, generating green doubled frequency light with a wavelength of 532nm. The output intensity is about 1 times that of KDP under the same conditions.

Claims

1. A compound cesium sodium fluoroborate, characterized in that The compound has the chemical formula NaCs7[B3O3F4(OH)]4(H2O)3, a molecular weight of 1701.16, and is prepared using a room temperature solution method.

2. The method for preparing the compound cesium sodium fluoroborate as claimed in claim 1, characterized in that The room temperature solution method is used for preparation, and the specific operation is carried out according to the following steps: The Na-containing compound, the Cs-containing compound and the B- and F-containing compounds are uniformly mixed in a molar ratio of Na:Cs:B:F=1:7:12:16, put into a clean plastic container, add 20-100 mL of deionized water, and then perform ultrasonic treatment to fully mix and dissolve, filter with filter paper to obtain a mixed solution, and then seal with plastic wrap, poke a number of small holes in the seal, and stand at a temperature of 40-50 ° C for 5-20 days to obtain the compound NaCs7[B3O3F4(OH)]4(H2O)3, wherein the Na-containing compound is NaHF2, NaF, Na2CO3, NaHCO3, and NaOH; the Cs-containing compound is CsHF2, CsF, Cs2CO3, and CsHCO3; the B-containing compound is H3BO3, HBO2, and B2O3; and the F-containing compound is HF and HBF4.

3. A sodium cesium fluoroborate nonlinear optical crystal, characterized in that The chemical formula of the crystal is NaCs7[B3O3F4(OH)]4(H2O)3, the molecular weight is 1701.16, the crystal belongs to the monoclinic system, and the space group is P 21, the unit cell parameters are a =11.5864(15), b =13.463(2), c = 12.5958(19), α = 90°, β = 90°, γ = 109.697 (5) °, the unit cell volume is 1849 (5) Å 3 .

4. The method for preparing the sodium cesium fluoroborate nonlinear optical crystal according to claim 3, characterized in that Growing crystals using room temperature solution method or hydrothermal method; The room temperature solution method for growing sodium cesium fluoroborate nonlinear optical crystal is specifically performed in the following steps: a. Mix the Na-containing compound, Cs-containing compound, B-containing compound and F-containing compound in a molar ratio of Na:Cs:B:F=1:7:12:16, put them into a clean plastic container, add 20-100 mL of deionized water, treat with ultrasonic wave to make them fully mixed and dissolved, filter and obtain a mixed solution; the Na-containing compound is NaHF2, NaF, Na2CO3, NaHCO3 or NaOH; the Cs-containing compound is CsHF2, CsF, Cs2CO3 or CsHCO3; the B-containing compound is H3BO3, HBO2 or B2O3; the F-containing compound is HF or HBF4; b. Place the mixed solution obtained in step a in a clean plastic container, seal it with weighing paper, place it in a static environment without shaking, pollution, or air convection, pierce a number of small holes in the seal to adjust the evaporation rate of water in the aqueous solution, and leave it at a temperature of 40-50° C. for 5-20 days; c. Waiting for the solution in step b to grow crystal particles at the bottom of the container until the size of the crystal particles no longer changes significantly, thereby obtaining seed crystals; d. Select the seed crystal with better quality in step c, suspend it in the mixed solution prepared in step b, and let it stand and grow for 10-30 days at a temperature of 40-50° C. to obtain NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystal; The hydrothermal method for growing sodium cesium fluoroborate nonlinear optical crystal is specifically performed in the following steps: The Na-containing compound, the Cs-containing compound, the B-containing compound and the F-containing compound are placed in a polytetrafluoroethylene beaker and mixed evenly, and then placed in a clean plastic container, 20-65 mL of water are added, and the mixture is stirred and mixed evenly, and filtered to obtain a mixed solution, wherein the Na-containing compound is NaHF2, NaF, Na2CO3, NaHCO3 or NaOH; the Cs-containing compound is CsHF2, CsF, Cs2CO3 or CsHCO3; the B-containing compound is H3BO3, HBO2 or B2O3; the F-containing compound is HF or HBF4; The mixed solution obtained in step a was transferred into the polytetrafluoroethylene liner of a 23 ml high-pressure reactor, deionized water was added as a solvent, and the mouth of the reactor was screwed and sealed; The high-pressure reactor in step b is placed in a thermostat and heated to 220°C at a rate of 20°C / h for 24 hours, and then cooled to room temperature at a rate of 2°C / h; The high-pressure reactor was opened, and millimeter-sized large-sized NaCs7[B3O3F4(OH)]4(H2O)3 nonlinear optical crystals were obtained in a colorless clear solution.

5. A use of the sodium cesium fluoroborate nonlinear optical crystal as claimed in claim 3 in preparing the 1064 nm fundamental frequency light output by a Nd: YAG laser for double- and triple-harmonic light output.

6. Use of the sodium cesium fluoroborate nonlinear optical crystal as claimed in claim 3 in the preparation of short-wavelength frequency-doubled light outputs of 266 nm and 355 nm.

7. Use of the sodium cesium fluoroborate nonlinear optical crystal as claimed in claim 3 in the preparation of a frequency doubling generator, an up or down frequency converter or an optical parametric oscillator.

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