阅读说明：本技术 氯硼酸锌非线性光学晶体及制备方法和用途 (Zinc chloroborate nonlinear optical crystal, preparation method and application ) 是由 龙西法 熊哲瑶 王祖建 何超 苏榕冰 杨晓明 于 2020-07-06 设计创作，主要内容包括：本发明涉及一种氯硼酸锌非线性光学晶体及制备方法和用途。所述氯硼酸锌晶体的化学式为Zn<Sub>3</Sub>B<Sub>7</Sub>O<Sub>13</Sub>Cl,属于三方晶系,空间群为R3c,晶胞参数为<Image he="69" wi="700" file="DDA0002572012300000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>α＝β＝90°,γ＝120°,Z＝6,<Image he="78" wi="440" file="DDA0002572012300000012.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>所述氯硼酸锌非线性光学晶体的粉末倍频效应约为KH<Sub>2</Sub>PO<Sub>4</Sub>(KDP)的2.2倍,能够实现相位匹配(基频光波长1064nm),紫外截止边为190nm,双折射率为0.03098(波长为407nm)。本发明还提供了一种氯硼酸锌晶体的制备方法,使用该方法得到的氯硼酸锌晶体不仅具有良好的非线性光学效应,而且化学性质稳定、不潮解、易于加工和保存,可用于制作多种光学器件。(The invention relates to a zinc chloroborate nonlinear optical crystal, a preparation method and application thereof. The chemical formula of the zinc chloroborate crystal is Zn 3 B 7 O 13 Cl, belonging to trigonal system, space group R3c, cell parameter α＝β＝90°，γ＝120°，Z＝6， The powder frequency doubling effect of the zinc chloroborate nonlinear optical crystal is about KH 2 PO 4 The phase matching (fundamental frequency light wavelength is 1064nm) can be realized by 2.2 times of (KDP), the ultraviolet cut-off edge is 190nm, and the birefringence is 0.03098 (wavelength is 407 nm). Book (I)The invention also provides a preparation method of the zinc chloroborate crystal, and the zinc chloroborate crystal obtained by the method not only has good nonlinear optical effect, but also has stable chemical property, no deliquescence, easy processing and storage, and can be used for manufacturing various optical devices.)

1. The zinc chloroborate crystal is characterized by comprising the chemical formulaIs of the formula Zn₃B₇O₁₃Cl, belonging to trigonal system, R3c space group, having a cell parameter of

Preferably, the zinc chloroborate crystals have an X-ray diffraction pattern substantially as shown in figure 2.

2. The crystal of claim 1, wherein the zinc chloroborate crystal has a powder fold frequency spectrum substantially as shown in figure 3;

preferably, the zinc chloroborate crystals have a transmission spectrum substantially as shown in figure 4;

preferably, the zinc chloroborate crystals have a birefringence curve substantially as shown in FIG. 5.

3. The crystal according to claim 1 or 2, wherein the zinc chloroborate crystal has an ultraviolet cut edge of 190 nm;

preferably, the zinc chloroborate crystal has a birefringence of 0.03098 at a wavelength of 407 nm.

4. A method for producing the crystal of any one of claims 1 to 3, comprising the steps of:

(a) preparing a zinc chloroborate compound by a high-temperature solid-phase method;

(b) preparing zinc chloroborate crystals by a high-temperature solution method;

the preparation method of the zinc chloroborate compound comprises the following steps: mixing a zinc source and a boron source, and reacting to obtain the zinc chloroborate compound;

the zinc source is selected from a zinc compound, theThe zinc compound being selected from ZnCl₂And/or ZnO;

the boron source is selected from boron compounds selected from B₂O₃And/or H₃BO₃。

5. The preparation method according to claim 4, wherein the molar ratio of the zinc element in the zinc source to the boron element in the boron source is 3 (7-9), preferably 3: 7;

preferably, the reaction temperature is 550-850 ℃, such as 600-800 ℃;

preferably, the reaction time is from 2 to 48h, for example from 2 to 24 h;

preferably, the preparation method of the zinc chloroborate compound comprises the following steps: by using ZnCl₂And H and₃BO₃grinding and mixing the raw materials uniformly, heating to 550-850 ℃, and keeping the temperature for 2-48 hours to obtain Zn₃B₇O₁₃A Cl compound.

6. The method according to claim 4 or 5, wherein the zinc chloroborate crystal is prepared by a method comprising the steps of: mixing a zinc chloroborate compound with a fluxing agent and then reacting to obtain zinc chloroborate crystals;

preferably, the fluxing agent is selected from ZnCl₂At least one of alkali metal chloride salt, alkaline earth metal chloride salt and boron compound;

preferably, the alkali metal chloride salt is selected from at least one of KCl, NaCl and LiCl;

preferably, the alkaline earth metal chloride salt is selected from CaCl₂、MgCl₂At least one of;

preferably, the boron compound is selected from B₂O₃And/or H₃BO₃。

7. The method according to any one of claims 4 to 6, wherein the molar ratio of the zinc chloroborate compound to the flux is (1-8): 1-8, for example 1: 1-6, such as 1: 1-4;

preferably, the reaction temperature is 850-1300 ℃, such as 900-1200 ℃;

preferably, the reaction time is from 2 to 48h, for example from 2 to 24 h;

preferably, after the reaction is finished, the temperature is reduced to 700 ℃ at the speed of 0.1-5 ℃/h, and then the temperature is reduced to room temperature at the speed of 10-50 ℃/h; preferably, the temperature is reduced to 700 ℃ at 1 ℃/h, and then the temperature is reduced to room temperature at 30 ℃/h.

8. The method according to any one of claims 4 to 7, wherein the reaction is carried out in a closed or protective atmosphere, wherein the protective atmosphere is Cl₂Gas, HCl gas or a mixture of the two.

According to an embodiment of the invention, the reaction can be washed with water after cooling to obtain zinc chloroborate crystals.

9. The method according to any one of claims 4 to 8, wherein the zinc chloroborate crystal is prepared by: uniformly mixing zinc chloroborate polycrystalline powder with a fluxing agent, raising the temperature to 850-1300 ℃, keeping the temperature, then cooling to 700 ℃ at the speed of 0.1-5 ℃/h, and then cooling to room temperature at the speed of 10-50 ℃/h to obtain zinc chloroborate crystals;

preferably, the temperature is reduced to 700 ℃ at 1 ℃/h, and then the temperature is reduced to room temperature at 30 ℃/h, so as to obtain the zinc chloroborate crystal.

10. Use of the zinc chloroborate crystal of any of claims 1 to 3 in optoelectronic devices, such as in the fields of nonlinear optics, birefringent optics, deep ultraviolet window devices, optoelectronic switches, solar cells, and the like.

Technical Field

The invention belongs to the technical field of crystal materials, and particularly relates to a zinc chloroborate nonlinear optical crystal, and a preparation method and application thereof.

Background

The nonlinear optical crystal is mainly used for laser frequency doubling, sum frequency, difference frequency, multiple frequency doubling, parametric oscillation, amplification and the like. The nonlinear optical crystal can change the output wavelength of a certain laser through a frequency conversion effect, so that new laser radiation is generated, and the application range of the laser is widened. The method has important application in the military and civil high-tech fields, such as laser blinding weapons, optical disc recording, laser projection televisions, optical computing, optical communication, photoetching technology, micro-nano fine processing and other fields.

Over decades of development, many nonlinear optical crystals have been put to practical use, such as: KDP, KTP, LN, BBO, LBO, KBBF, AgGaS₂And the like. The crystal can basically meet the requirement of frequency conversion of ultraviolet-visible-infrared band laser. But in the deep ultraviolet band (wavelength)<200nm) is also lacking. The KBBF crystal is the only nonlinear optical crystal which can realize the output of deep ultraviolet laser by six times of frequency multiplication at present, but the KBBF crystal has serious lamellar growth habit, so that the KBBF crystal is difficult to grow thick along the c direction, and the raw material BeO for growing the KBBF crystal is a carcinogen. Therefore, the search for new deep ultraviolet nonlinear optical crystals is still urgent and necessary.

Exploring a novel deep ultraviolet nonlinear optical crystal based on a quasi-phase matching technology is a new idea for solving the problem. Compared with the conventional common refractive index phase matching mode, the quasi-phase matching technology has unique advantages. The deep ultraviolet nonlinear optical crystal based on the quasi-phase matching mode can effectively avoid the restriction of birefringence and realize phase matching in the whole transparent area of the crystal. In addition, the quasi-phase matching mode has the advantages of simple and various tuning modes, no walk-off effect, capability of utilizing the maximum nonlinear coefficient of the crystal and the like. In order to realize the quasi-phase matching of the deep ultraviolet band, the nonlinear optical crystal is required to meet the following requirements: large nonlinear optical coefficients (at least comparable to KDP), short uv cut-off (<200nm), and large birefringence.

Disclosure of Invention

In order to meet the application requirements, the invention provides a zinc chloroborate crystal, and the chemical formula of the zinc chloroborate crystal is Zn₃B₇O₁₃Cl, belonging to trigonal system, space group R3c, cell parameterα＝β＝90°，γ＝120°，Z＝6，

According to an embodiment of the present invention, the zinc chloroborate crystals have an X-ray diffraction pattern substantially as shown in figure 2.

According to an embodiment of the present invention, the zinc chloroborate crystals have a powder fold frequency spectrum substantially as shown in figure 3.

According to an embodiment of the invention, the zinc chloroborate crystals have a transmission spectrum substantially as shown in figure 4. According to an embodiment of the present invention, the zinc chloroborate crystals have a birefringence curve substantially as shown in fig. 5.

According to an embodiment of the present invention, the ultraviolet cut edge of the zinc chloroborate crystal is 190 nm.

According to an embodiment of the present invention, the zinc chloroborate crystal has a birefringence 0.03098 at a wavelength of 407 nm.

The invention also provides a preparation method of the zinc chloroborate crystal, which comprises the following steps:

(a) preparing a zinc chloroborate compound by a high-temperature solid-phase method;

(b) preparing zinc chloroborate crystals by a high-temperature solution method;

according to an embodiment of the present invention, the method for preparing the zinc chloroborate compound comprises the steps of: mixing a zinc source and a boron source, and reacting to obtain the zinc chloroborate compound;

according to an embodiment of the invention, the zinc source is selected from zinc compounds selected from ZnCl₂And/or ZnO;

according to an embodiment of the invention, the boron source is selected from boron compounds selected from B₂O₃And/or H₃BO₃；

According to an embodiment of the present invention, the molar ratio of the zinc element in the zinc source to the boron element in the boron source is 3 (7-9), such as 3:7, 3:8, 3:9, preferably 3: 7;

according to embodiments of the invention, the reaction temperature is 550-;

according to an embodiment of the invention, the reaction time is 2-48h, for example 2-24h, exemplarily 3 h.

According to an embodiment of the present invention, the zinc chloroborate compound is prepared by: by using ZnCl₂And H and₃BO₃grinding and mixing the raw materials uniformly, heating to 550-850 ℃, and keeping the temperature for 2-48 hours to obtain Zn₃B₇O₁₃A Cl compound.

According to an embodiment of the present invention, the method for preparing the zinc chloroborate crystal comprises the following steps: : mixing a zinc chloroborate compound with a fluxing agent and then reacting to obtain zinc chloroborate crystals;

according to an embodiment of the invention, the fluxing agent is chosen from ZnCl₂At least one of alkali metal chloride salt, alkaline earth metal chloride salt and boron compound;

according to an embodiment of the present invention, the alkali metal chloride salt is selected from at least one of KCl, NaCl, LiCl;

according to an embodiment of the invention, the alkaline earth metal chloride salt is selected from CaCl₂、MgCl₂At least one of;

according to the inventionEmbodiments, the boron compound is selected from B₂O₃And/or H₃BO₃。

According to an embodiment of the invention, the molar ratio of the zinc chloroborate compound to the flux is (1-8): 1-8), for example 1: 1-6, such as 1: 1-4, exemplary 1:1, 1:2, 1:3, 1: 4;

according to embodiments of the invention, the reaction temperature is 850-1300 ℃, such as 900-1200 ℃, exemplary 1000 ℃;

according to an embodiment of the invention, the reaction time is 2-48h, for example 2-24h, exemplarily 12 h;

according to the embodiment of the invention, after the reaction is finished, the temperature is reduced to 700 ℃ at the speed of 0.1-5 ℃/h, and then the temperature is reduced to room temperature at the speed of 10-50 ℃/h; preferably, the temperature is reduced to 700 ℃ at 1 ℃/h, and then the temperature is reduced to the room temperature at 30 ℃/h;

according to an embodiment of the present invention, the reaction may be carried out under a closed or protective atmosphere, the protective atmosphere being Cl₂Gas, HCl gas or a mixture of the two.

According to an embodiment of the invention, the reaction can be washed with water after cooling to obtain zinc chloroborate crystals.

According to the embodiment of the invention, the preparation method of the zinc chloroborate crystal comprises the following steps: uniformly mixing zinc chloroborate polycrystalline powder with a fluxing agent, raising the temperature to 850-1300 ℃, keeping the temperature, then cooling to 700 ℃ at the speed of 0.1-5 ℃/h, and then cooling to room temperature at the speed of 10-50 ℃/h to obtain zinc chloroborate crystals; preferably, the temperature is reduced to 700 ℃ at 1 ℃/h, and then the temperature is reduced to room temperature at 30 ℃/h, so as to obtain the zinc chloroborate crystal.

The invention also provides application of the zinc chloroborate crystal in photoelectric devices, such as nonlinear optical devices, birefringent optical devices, deep ultraviolet window devices, photoelectric switches, solar cells and other fields.

Advantageous effects

The invention has the following beneficial effects:

the zinc chloroborate crystal provided by the invention has a large nonlinear optical effect (about 2.2 times KDP), a short ultraviolet cut-off edge (190nm) and a large birefringence (0.03098 at a wavelength of 407 nm). The zinc chloroborate crystal has the advantages of difficult deliquescence, water insolubility, high hardness, good mechanical property and the like. The crystal is a good deep ultraviolet nonlinear photoelectric functional crystal, and can be widely applied to the fields of nonlinear optical devices, birefringent optical devices, deep ultraviolet window devices, photoelectric switches, solar cells and the like.

Drawings

FIG. 1 shows Zn of the present invention₃B₇O₁₃Crystal structure diagram of Cl

FIG. 2 shows Zn of the present invention₃B₇O₁₃Powder X-ray diffraction pattern of Cl

FIG. 3 shows Zn of the present invention₃B₇O₁₃Powder frequency doubling pattern of Cl

FIG. 4 shows Zn of the present invention₃B₇O₁₃Transmission spectrum of Cl crystal

FIG. 5 shows Zn of the present invention₃B₇O₁₃Birefringence map of Cl crystals

Detailed Description

The technical solution of the present invention will be further described in detail with reference to specific embodiments. It is to be understood that the following examples are only illustrative and explanatory of the present invention and should not be construed as limiting the scope of the present invention. All the technologies realized based on the above-mentioned contents of the present invention are covered in the protection scope of the present invention.

Unless otherwise indicated, the raw materials and reagents used in the following examples are all commercially available products or can be prepared by known methods.