CN113322518B - Guanidine phosphate ultraviolet frequency doubling crystal material, preparation and application thereof - Google Patents

Abstract

The invention relates to a guanidine phosphate ultraviolet frequency-doubling crystal material and its preparation and application. The chemical formula of the guanidine phosphate material is [C(NH ₂ ) ₃ ] ₆ (PO ₄ ) ₂ ·3H ₂ O, which belongs to the monoclinic crystal system. Its space group is Cc, and the unit cell parameter of guanidine phosphate material is

β=91.90～92.20°, α=γ=90°, Z=4. Compared with the existing materials, the guanidine phosphate material of the present invention has a larger frequency doubling effect, and the frequency doubling intensity of the powder is about 3.8 times that of KH ₂ PO ₄ (KDP) crystal under the irradiation of 1064 nm laser; under the irradiation of 532 nm laser The intensity of frequency doubling effect of powder was measured to be about 0.3 times that of β-BaB ₂ O ₄ crystal. In addition, the UV absorption cut-off edge of the material is at 205 nm, which has broad application prospects in the fields of laser frequency conversion, photoelectric modulation, and laser signal holographic storage.

Description

A kind of guanidine phosphate ultraviolet frequency doubling crystal material and its preparation and application

technical field

The invention belongs to the technical field of optical crystal materials, and relates to a guanidine phosphate ultraviolet frequency-doubling crystal material and its preparation and application.

Background technique

The typical feature of second-order nonlinear optical crystals is the frequency doubling effect (SHG), which is an important optoelectronic functional material and has important application prospects in the fields of laser frequency conversion, optoelectronic modulation, and laser signal holographic storage. Inorganic nonlinear optical crystal materials can be divided into ultraviolet light region nonlinear optical materials, visible light region nonlinear optical materials and infrared light region nonlinear optical materials according to the light transmission band and application range. Currently commercialized nonlinear optical materials in the ultraviolet and visible regions include BBO (β-barium metaborate), CsB ₃ O ₅ (cesium borate), LBO (lithium borate), KDP (potassium dihydrogen phosphate), KTP (phosphoric acid) Potassium titanate) etc. However, commercialized nonlinear optical materials in the ultraviolet region are still difficult to meet practical demands. For example, the large birefringence of BBO leads to no light-induced refraction effect and the reduction of SHG intensity; CBO is easy to absorb moisture and so on. Therefore, the research of UV optical frequency-doubling crystal materials has become an important research direction in the field of inorganic materials.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a guanidine phosphate ultraviolet frequency-doubling crystal material and its preparation and application.

The object of the present invention can be realized through the following technical solutions:

One of the technical solutions of the present invention provides a guanidine phosphate ultraviolet frequency-doubling crystal material, the chemical formula of which is [C(NH ₂ ) ₃ ] ₆ (PO ₄ ) ₂ ·3H ₂ O.

β＝91.90～92.20°，α＝γ＝90°，Z＝4，

Further, the material belongs to the monoclinic crystal system, its space group is Cc, and the unit cell parameter is

β=91.90～92.20°, α=γ=90°, Z=4,

The crystal structure of the guanidine phosphate material of the present invention is as follows: each asymmetric unit contains three phosphate groups, six guanidine molecules and three water molecules. Phosphate radicals, guanidine molecules in a planar triangular configuration, and water molecules are connected in space to form a three-dimensional structure by hydrogen bonding. The PO ₄ polyhedrons are basically aligned along the c-axis direction. This arrangement is beneficial to increase the polarity of the compound, thereby enhancing its nonlinear optical coefficient.

The second technical solution of the present invention provides a method for preparing a guanidine phosphate ultraviolet frequency-doubling crystal material, which is characterized in that the target product is obtained by mixing a phosphorus source, a guanidine source and water, and then volatilizing and crystallizing.

Further, the phosphorus source is selected from at least one of dipotassium hydrogen phosphate, potassium dihydrogen phosphate, phosphoric acid, disodium hydrogen phosphate or sodium dihydrogen phosphate. Further, the phosphorus source is dipotassium hydrogen phosphate.

Further, the guanidine source is selected from at least one of guanidine carbonate, guanidine sulfate or guanidine nitrate. Further, the guanidine source is guanidine carbonate.

Further, the addition amounts of the phosphorus source and the guanidine source satisfy: the molar ratio of the phosphorus element and the guanidine molecule is 1:(0.5-10).

Further, after the phosphorus source, the guanidine source and the water are mixed, the molar concentration of the phosphorus element is 0.01-2 mol/L. Further, the molar concentration of phosphorus element is 0.02-1.2 mol/L.

Further, the volatilization crystallization is carried out at 5-30° C., and the volatilization and crystallization time is not less than 72 hours.

The third technical solution of the present invention provides the application of a guanidine phosphate ultraviolet frequency-doubling crystal material in a laser frequency converter. The guanidine phosphate crystal material prepared by the invention has a strong ultraviolet frequency doubling effect. The powder frequency doubling effect is about 3.8 times that of KDP crystal under 1064nm laser irradiation, and the powder frequency doubling effect measured under 532nm laser irradiation is 0.3 times that of BBO, and phase matching can be achieved. In addition, the UV optical absorption cut-off edge of this crystalline material is 205 nm.

Compared with the prior art, the present invention has the following advantages:

(1) The guanidine phosphate ultraviolet frequency doubling crystal material of the present invention has a strong frequency doubling effect and a wide range of ultraviolet optical transmission, and its powder frequency doubling effect is about 3.8 times that of KDP crystal under 1064nm laser irradiation. The intensity of powder frequency doubling effect measured under irradiation is 0.3 times that of BBO, and phase matching can be achieved. The UV optical absorption cutoff of the crystalline material is 205 nm.

(2) The present invention adopts the reaction condition room temperature volatilization method, and can quickly obtain high-purity samples at a temperature of 0-25°C. The method is simple and the conditions are mild, which is favorable for realizing large-scale industrial production.

(3) The guanidine phosphate material of the present invention can be applied to a laser frequency converter, and can be used to output laser beams with wavelengths of 1064 nm and 532 nm at double frequency harmonics.

Description of drawings

Figure 1 is a schematic diagram of the crystal structure of [C(NH ₂ ) ₃ ] ₆ (PO ₄ ) ₂ .3H ₂ O;

Fig. 2 is the X-ray diffraction pattern comparison;

Fig. 3 is the ultraviolet transmission spectrum of sample 1#;

Figure 4 is the second harmonic signal diagram of sample 1# and standard KDP sample size in the range of 105-150μm;

Figure 5 is the second harmonic phase matching diagram of sample 1# in the 532nm band;

Figure 6 is the second harmonic signal diagram of sample 1# and standard BBO sample size in the range of 105-150μm;

Figure 7 is the second harmonic phase matching diagram of sample 1# in the 532nm band.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and provides a detailed implementation manner and a specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

In the following examples, if there is no special description of raw material products or process technologies, it is indicated that they are all conventional commercially available products or conventional processing technologies in this field.

Example 1:

Preparation of samples 1#～8#

The phosphorus source, guanidine source and water are mixed into raw materials according to a certain proportion. After the raw materials are dissolved, they are placed in a beaker to obtain colorless lumps of [C(NH ₂ ) ₃ ] ₆ (PO ₄ ) ₂ ·3H. ₂ O crystals.

The relationship between the types and proportions of raw materials in the initial mixture, the crystallization temperature, the crystallization time and the sample number is shown in Table 1.

Table 1 Correspondence between samples and raw materials and synthesis conditions

Crystal structure analysis of samples 1#～8#

The structures of samples 1# to 8# were analyzed by single crystal X-ray diffraction and powder X-ray diffraction methods.

扫描方式为ω；数据采用Multi-Scan方法进行吸收校正处理。结构解析采用SHELXTL-97程序包完成；用直接法确定重原子的位置，用差值傅立叶合成法得到其余原子坐标；用基于F²的全矩阵最小二乘法精修所有原子的坐标及各向异性热参数。The single-crystal X-ray diffraction was performed on a D8 VENTURE CMOS X-ray single-crystal diffractometer from Bruker, Germany. The data collection temperature was 293K, and the diffraction light source was graphite monochromatic Mo-Kα rays

The scanning mode is ω; the data is processed by the Multi-Scan method for absorption correction. Structural analysis was completed using the SHELXTL-97 package; the positions of heavy atoms were determined by the direct method, and the coordinates of the remaining atoms were obtained by the difference Fourier synthesis method; the coordinates and anisotropy of all atoms were refined by the full-matrix least squares method based on F ² thermal parameters.

电压电流为40kV/20A，狭缝DivSlit/RecSlit/SctSlit分别为2.00deg/0.3mm/2.00deg，扫描范围5～70°，扫描步长0.02°。Powder X-ray diffraction was carried out on a Bruker D8 X-ray powder diffractometer from Bruker, Germany, and the test conditions were a fixed target monochromatic light source Cu-Kα, wavelength

The voltage and current are 40kV/20A, the slit DivSlit/RecSlit/SctSlit are 2.00deg/0.3mm/2.00deg respectively, the scanning range is 5-70°, and the scanning step is 0.02°.

β＝91.90～92.20°，α＝γ＝90°，Z＝4，晶胞体积为

Among them, the single crystal X-ray diffraction results show that samples 1# to 8# have the same chemical structural formula and crystal structure, the chemical formula is [C(NH ₂ ) ₃ ] ₆ (PO ₄ ) ₂ ·3H ₂ O, which belongs to monoclinic crystal system, its space group is Cc, and the unit cell parameters are

β=91.90～92.20°, α=γ=90°, Z=4, the unit cell volume is

α＝γ＝90°，β＝92.088，Z＝4，晶胞体积为

样品1#各原子坐标如表2所示，其晶体结构如图1所示。Taking sample 1# as a typical representative, its crystal structure data is

α=γ=90°, β=92.088, Z=4, the unit cell volume is

The atomic coordinates of Sample 1# are shown in Table 2, and its crystal structure is shown in Figure 1.

Table 2. Atomic coordinates and equivalent thermal parameters in sample 1#

The powder X-ray diffraction results show that the peak positions of samples 1# to 8# are basically the same on the XRD spectrum, and the peak intensity of each sample is slightly different.

Taking sample 1# as a typical representative, as shown in Figure 2, according to the crystal structure analyzed by its single crystal X-ray diffraction, the X-ray diffraction pattern obtained by fitting is the same as that obtained by X-ray diffraction test after grinding sample 1# into powder. The spectra, peak positions and intensities are consistent. The obtained samples have high purity.

UV-Vis-NIR Absorption Spectroscopy

The diffuse reflectance absorption spectrum test of sample 1# was carried out on a Carry 5000 UV-Vis-NIR spectrophotometer from Agilent, USA. The results are shown in Fig. 3. It can be seen from Fig. 3 that the UV absorption cut-off edge of the compound is at 205 nm, and the optical band gap is 6.05 eV.

Frequency doubling test experiment and results

The frequency doubling test experiment of sample 1# is as follows: the wavelengths of 1064nm and 532nm generated by a Q-switched Nd:YAG solid-state laser are used as the fundamental frequency light to irradiate the tested crystal powder, and a photomultiplier tube is used to detect the generated secondary light. Harmonics, display the harmonic intensity with an oscilloscope. Grind the crystal samples and standard samples KDP and BBO crystals separately, and sieve crystals with different particle sizes with a standard sieve. ～200, 200～280, 280～350μm. Observe the change trend of the frequency multiplied signal with the particle size, and judge whether it can achieve phase matching. Under the same test conditions, compare the second harmonic intensity generated by the sample and the reference crystal KDP under the 1064nm wavelength laser irradiation, and the second harmonic intensity generated by the sample and the reference crystal BBO under the 532nm wavelength laser irradiation, respectively. Thereby, the relative magnitude of the frequency doubling effect of the sample is obtained.

The test results show that the compound [C(NH ₂ ) ₃ ] ₆ (PO ₄ ) ₂ ·3H ₂ O crystal has a large frequency doubling effect, and the frequency doubling signal intensity is 3.8 times that of KDP crystal under the irradiation of 1064 nm wavelength laser. (as shown in Figure 4); under the irradiation of 532nm wavelength laser, the intensity of the frequency-doubling signal is 0.3 times that of the AgGaS ₂ crystal (as shown in Figure 6). As shown in Figure 5 and Figure 7, the crystal material can achieve phase matching in the above two laser wavelength bands.

Example 2

A preparation method similar to that of Example 1 was adopted, except that:

(1) the phosphorus source adopted is phosphoric acid, and the guanidine source adopted is guanidine carbonate, wherein the addition of the phosphorus source and the guanidine source satisfies: the molar ratio of phosphorus element, guanidine molecule and water is 1:3:150;

(2) The crystallization temperature used was 25°C, and the crystallization time was 300 hours.

After testing, the prepared compound [C(NH ₂ ) ₃ ] ₆ (PO ₄ ) ₂ ·3H ₂ O crystal has a great frequency doubling effect. Under the irradiation of 1064nm wavelength laser, the frequency doubling signal intensity is about KDP 3.8 times that of the crystal; under the irradiation of the 532nm wavelength laser, the intensity of the frequency-doubling signal is about 0.3 times that of the BBO crystal.

Example 3

A preparation method similar to that of Example 1 was adopted, except that:

(1) the phosphorus source adopted is potassium dihydrogen phosphate, and the guanidine source adopted is guanidine carbonate, wherein, the addition of phosphorus source and guanidine source satisfies: the mol ratio of phosphorus element and guanidine molecule is 1:1;

(2) The crystallization temperature used was 20°C, and the crystallization time was 500 hours.

After testing, the prepared compound [C(NH ₂ ) ₃ ] ₆ (PO ₄ ) ₂ ·3H ₂ O crystal has a great frequency doubling effect. Under the irradiation of 1064nm wavelength laser, the frequency doubling signal intensity is about KDP 3.8 times that of the crystal; under the irradiation of the 532nm wavelength laser, the intensity of the frequency-doubling signal is about 0.3 times that of the BBO crystal.

Example 4

A preparation method similar to that of Example 1 was adopted, except that:

(1) the phosphorus source adopted is dipotassium hydrogen phosphate, and the guanidine source adopted is guanidine carbonate, wherein, the addition of phosphorus source, guanidine source satisfies: the mol ratio of phosphorus element, guanidine molecule and water is 1:1:100;

(2) The crystallization temperature used was 20°C, and the crystallization time was 500 hours.

After testing, the prepared compound [C(NH ₂ ) ₃ ] ₆ (PO ₄ ) ₂ ·3H ₂ O crystal has a great frequency doubling effect. Under the irradiation of 1064nm wavelength laser, the frequency doubling signal intensity is about KDP 3.8 times that of the crystal; under the irradiation of the 532nm wavelength laser, the intensity of the frequency-doubling signal is about 0.3 times that of the BBO crystal.

Example 5

A preparation method similar to that of Example 1 was adopted, except that:

(1) the phosphorus source adopted is potassium dihydrogen phosphate, and the guanidine source adopted is guanidine sulfate, wherein, the addition of phosphorus source and guanidine source satisfies: the mol ratio of phosphorus element, guanidine molecule and water is 1:0.5:100;

(2) The crystallization temperature used was 20°C, and the crystallization time was 400 hours.

After testing, the prepared compound [C(NH ₂ ) ₃ ] ₆ (PO ₄ ) ₂ ·3H ₂ O crystal has a great frequency doubling effect. Under the irradiation of 1064nm wavelength laser, the frequency doubling signal intensity is about KDP 3.8 times that of the crystal; under the irradiation of the 532nm wavelength laser, the intensity of the frequency-doubling signal is about 0.3 times that of the BBO crystal.

Example 6

Compared with Example 1, most of the parts are the same, except that in this example, sodium dihydrogen phosphate is used as the phosphorus source.

Example 7

Compared with Example 1, most of them are the same, except in this example: the molar ratio of phosphorus element, guanidine molecule and water in the initial mixture is 1:8:50.

Example 8

Compared with Example 1, most of them are the same, except in this example: the molar ratio of phosphorus element, guanidine molecule and water in the initial mixture is 1:3:100.

Example 9

Compared with Example 1, most of them are the same, except in this example: the molar ratio of phosphorus element, guanidine molecule and water in the initial mixture is 1:0.3:20.

Example 10

Compared with Example 1, most of them are the same, except in this example: the molar ratio of phosphorus element, guanidine molecule and water in the initial mixture is 1:6:10.

In the above embodiments, the added amount of each raw material and the crystallization process conditions can be arbitrarily selected within the following ranges: the range of the added amount of phosphorus source and guanidine source satisfies: phosphorus element, guanidine molecule The molar ratio of phosphorus element is 1:(0.5～10); after phosphorus source, guanidine source and water are mixed, the molar concentration of phosphorus element is 0.01～2mol/L.

The foregoing description of the embodiments is provided to facilitate understanding and use of the invention by those of ordinary skill in the art. It will be apparent to those skilled in the art that various modifications to these embodiments can be readily made, and the generic principles described herein can be applied to other embodiments without inventive step. Therefore, the present invention is not limited to the above-mentioned embodiments, and improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should all fall within the protection scope of the present invention.

Claims (9)

1. The guanidine phosphate ultraviolet frequency doubling crystal material is characterized in that the chemical formula is [ C (NH)₂)₃]₆(PO₄)₂·3H₂O；

The material belongs to a monoclinic system, the space group is Cc, the cell parameter is Cc

β＝91.90～92.20°，α＝γ＝90°，Z＝4，

2. The method for preparing guanidine phosphate ultraviolet frequency doubling crystal material according to claim 1, wherein the target product is obtained by mixing a phosphorus source, a guanidine source and water, and then volatilizing and crystallizing.

3. The method for preparing guanidine phosphate ultraviolet frequency doubling crystal material according to claim 2, wherein the phosphorus source is at least one selected from dipotassium hydrogen phosphate, potassium dihydrogen phosphate, phosphoric acid, disodium hydrogen phosphate and sodium dihydrogen phosphate.

4. The method for preparing guanidine phosphate ultraviolet frequency doubling crystal material according to claim 2, wherein the guanidine source is at least one of guanidine carbonate, guanidine sulfate or guanidine nitrate.

5. The method for preparing the guanidine phosphate ultraviolet frequency doubling crystal material according to claim 2, wherein the addition amount of the phosphorus source and the guanidine source satisfies the following requirements: the molar ratio of the phosphorus element to the guanidine molecules is 1 (0.5-10).

6. The method for preparing the guanidine phosphate ultraviolet frequency doubling crystal material according to claim 2, wherein the molar concentration of phosphorus element is 0.01-2 mol/L after the phosphorus source, the guanidine source and water are mixed.

7. The method for preparing the guanidine phosphate ultraviolet frequency doubling crystal material according to claim 6, wherein the molar concentration of phosphorus element is 0.02-1.2 mol/L.

8. The preparation method of the guanidine phosphate ultraviolet frequency doubling crystal material according to claim 2, wherein the volatilization crystallization is performed at 5-30 ℃, and the volatilization crystallization time is not less than 72 h.

9. The use of the guanidine phosphate ultraviolet frequency doubling crystal material according to claim 1 in a laser frequency converter.

Images