A processing method for inhibiting the generation of microstreaks in halogenated mercurous crystal processing

Abstract

This invention provides a processing method for suppressing the generation of microstripes during the processing of mercury halide crystals. The method includes the following steps: grinding the mercury halide crystal with a coarse-grained Al₂O₃ polishing slurry with a particle size of 10-20 μm to remove the surface damage layer caused by the cutting of the mercury halide; performing a secondary polishing of the mercury halide sample with a medium-grained Al₂O₃ polishing slurry with a particle size of 0.5-3 μm to eliminate scratches introduced by the corundum grinding disc; and performing precision polishing of the mercury halide sample with a fine-grained Al₂O₃ polishing slurry with a particle size of 0.01-0.1 μm to remove the pitted depressions left on the surface of the mercury halide crystal. This invention can effectively suppress cleavage striations generated on the (001) facet of the mercury halide crystal during processing, and the crystallinity of the crystal surface is significantly improved. The processed crystals in different orientations have high-quality surfaces and can be used in high-performance infrared polarizing / acoustic-optic devices.

Description

Technical Field

[0001] This invention relates to a processing method for suppressing the generation of microstripes during the processing of mercury halide crystals, belonging to the field of crystal element processing and surface defect elimination. Background Technology

[0002] Polarizing / acousto-optic devices are primarily used for optical modulation and are indispensable components in optical systems, finding wide applications in fiber optic communication, laser engineering, optical information processing, and spectral imaging. Materials used in polarizing devices generally require optical properties such as wide transmittance and high birefringence. Currently, commercially available polarizing crystals and devices such as α-BBO, calcite, and YVO4 in the ultraviolet, visible, and near-infrared bands largely meet commercial needs. However, high-performance polarizing crystals are still lacking in the mid- and far-infrared bands (3-12 micrometers). For acousto-optic devices, in addition to the aforementioned optical performance requirements, crystal materials are also required to possess acoustic properties such as low acoustic attenuation and a high acousto-optic quality factor. Currently, commercially available acousto-optic crystals such as KDP, TeO2, and PbMO4 exist in the ultraviolet-visible-near-infrared bands, but practical acousto-optic crystal materials are still lacking in the mid- and far-infrared region. Mercurous halide (Hg2X2, where X = Cl, Br, I) crystals possess excellent properties such as high birefringence, wide infrared transmission range, low sound velocity, and high acousto-optic quality factor. They are not only high-performance long-wave infrared polarizing materials, but also a class of promising high-performance long-wave infrared acousto-optic crystal materials.

[0003] Hg2X2 (X = Cl, Br, I) series crystals all belong to the tetragonal crystal system, space group I4 / mmm. Hg2X2 series crystals have a one-dimensional chain structure, with linear X-Hg-Hg-X molecules arranged along the c-axis within the unit cell. The molecules are bound by covalent bonds within the unit cell, while intermolecular forces bind them together. The one-dimensional chain structure of Hg2X2 crystals results in very large optical and acoustic anisotropy. Currently, although some research institutions have conducted studies on the growth and properties of mercury halide crystals, the Mohs hardness of the crystals is only about 2, which is very low. Furthermore, the intermolecular van der Waals forces are very weak, leading to easy cleavage along the (110) plane. This easily generates cleavage stripe defects during crystal growth and processing, reducing the surface crystallization quality of the crystal and significantly lowering the performance of optical components. The literature “Growth and Temperature-Dependent Mechanical and Thermal Properties of One-Dimensional Chain Structure Hg2Br2 Crystals for Infrared Acousto-Optic Device Application (Crystal Growth & Design, 2021, 21(12), 7034-7042)” reports the current optimal value of the half-width at half-maximum (WHM) of the rocking curve for mercurous bromide single crystals, but it is still as high as 0.29°. The literature “Growth of high quality mercurous halide single crystals by physical vapor transport method for AOM and radiation detection applications (Journal of Crystal Growth, 2016, 450, 96-102)” reports that the current WHM of the rocking curve after processing mercurous iodide is 0.24°. The large WHM of the rocking curve of processed mercurous halide crystals makes crystal processing difficult and results in low crystal quality. The existing reports do not give the reason for the large WHM of the X-ray rocking curve of mercurous halide crystals, nor do they provide detailed observation of the processed crystal surface.

[0004] Therefore, there is an urgent need to develop a processing method that can effectively suppress the formation of microstripes in mercurous halide crystals, thereby improving the crystal surface crystallization quality. To this end, this invention is proposed. Summary of the Invention

[0005] To address the shortcomings of existing technologies, particularly the difficulty in generating microstripes during the processing of mercury halide crystals, this invention provides a processing method to suppress the generation of microstripes during the processing of mercury halide crystals. In their research on mercury halide crystals, the inventors of this application have discovered for the first time that mercury halide crystals processed by traditional polishing processes exhibit microstripes on the (001) surface, and the stripe structure is neatly arranged. Research indicates that this is mainly due to the mechanical stress introduced by subsequent processing (cutting, polishing), causing the crystal to... <110> The directional cleavage negatively impacts the light transmission of the crystal. This invention addresses this by optimizing the polishing process to suppress internal micro-stripes in mercurous halide crystals, thereby improving the quality of the processed crystal. The resulting crystal exhibits a significantly reduced full width at half maximum (FWHM) on the X-ray single-crystal rocking curve, indicating a marked elimination of crystal defects and a substantial improvement in crystallinity.

[0006] To solve the above technical problems, the present invention is achieved through the following technical solution:

[0007] A processing method for suppressing the generation of microstripes during the processing of mercurous halide crystals includes the following steps:

[0008] (1) Use coarse-grained Al2O3 polishing slurry with a particle size of 10-20μm to grind mercury halide crystals to remove the surface damage layer caused by mercury halide cutting.

[0009] (2) The mercurous halide sample obtained in step (1) was polished a second time using a medium-particle size Al2O3 polishing slurry with a particle size of 0.5-3μm to eliminate the scratches introduced by grinding.

[0010] (3) The mercury halide sample obtained in step (2) is precisely polished with fine Al2O3 polishing liquid with a particle size of 0.01-0.1μm to remove the pitted depressions left on the surface of the mercury halide crystal, thus completing the processing of the mercury halide crystal.

[0011] According to a preferred embodiment of the present invention, the mercurous halide crystal in step (1) is a mercurous chloride crystal, a mercurous bromide crystal, or a mercurous iodide crystal; the mercurous halide crystal is obtained by orientation and cutting of a large-size mercurous halide bulk crystal grown by the PVT method, and the PVT growth method is a prior art in the field.

[0012] More preferably, the orientation step is as follows: a YX-2 type X-ray orientation instrument is used to orient a large-sized mercurous halide crystal. During the crystal orientation process, the orientation calibration is first performed on the two mutually perpendicular natural planes (110) at the end of the crystal. Then, the (001) plane of the mercurous halide crystal is determined by the relationship that the (001) plane of the crystal is perpendicular to both of the two mutually perpendicular natural planes. Finally, based on the determined (110) and (001) diffraction planes, the other diffraction planes of the mercurous halide crystal can be determined by the angular relationship. This method is simple to operate and has high orientation accuracy (error within 0.1°). The YX-2 type X-ray orientation instrument is a commercially available device.

[0013] More preferably, the cutting step is as follows: based on the completed crystal orientation, a large-size mercury halide bulk crystal is cut using an STX-202A diamond wire cutting machine to obtain a mercury halide crystal, wherein the cutting speed is 0.05-0.1 mm / min and the rotation speed is 150-200 r / min. The STX-202A diamond wire cutting machine is a commercially available device.

[0014] According to a preferred embodiment of the present invention, in step (1), the particle size of the coarse-grained Al2O3 is 14 μm; the coarse-grained Al2O3 polishing liquid is obtained by dispersing coarse-grained Al2O3 in ethylene glycol, and the mass ratio of the coarse-grained Al2O3 to the volume ratio of ethylene glycol is 0.01-0.1 g:1 mL, more preferably 0.05-0.1 g:1 mL.

[0015] According to a preferred embodiment of the present invention, the grinding time in step (1) is 10-20 min, and more preferably 15 min.

[0016] According to a preferred embodiment of the present invention, the grinding in step (1) is performed on a corundum grinding disc, which is cylindrical and made of white corundum (Al2O3).

[0017] According to the present invention, the use of a specific relatively coarse Al2O3 particle size and short grinding time in step (1) helps to fully remove the surface damage layer caused by cutting and causes less damage to subsequent polishing.

[0018] According to a preferred embodiment of the present invention, in step (2), the particle size of the medium-sized Al2O3 is 1 μm; the medium-sized Al2O3 polishing liquid is obtained by dispersing the medium-sized Al2O3 in ethylene glycol, and the mass ratio of the medium-sized Al2O3 to the volume of ethylene glycol is 0.01-0.05 g: 1 mL.

[0019] According to a preferred embodiment of the present invention, the secondary polishing time in step (2) is 10-20 min, more preferably 10 min; polishing with a specific relatively moderate particle size and time helps to fully eliminate scratches introduced by grinding.

[0020] According to a preferred embodiment of the present invention, in step (3), the particle size of the fine-grained Al2O3 is 0.05 μm.

[0021] According to a preferred embodiment of the present invention, the fine-particle Al2O3 polishing liquid in step (3) is obtained by dispersing fine-particle Al2O3 in ethylene glycol, wherein the mass ratio of the fine-particle Al2O3 to the volume ratio of ethylene glycol is 0.01-0.05 g: 1 mL.

[0022] According to the present invention, the precision polishing time in step (3) is preferably 10-20 min, and more preferably 10 min; the relatively suitable polishing time helps to fully remove the pitted depressions left on the surface of the mercury halide crystal, and further completely remove the surface scratches, so that the crystal can finally meet the requirements of high optical surface quality.

[0023] According to a preferred embodiment of the present invention, the polishing process in steps (2) and (3) is carried out on a polishing damping cloth; the polishing damping cloth is of model SH-10, has a thickness of 1.0 mm, a hardness of 65 JIS-A, and is made of polyurethane.

[0024] According to a preferred embodiment of the present invention, the processing in steps (1)-(3) is carried out at a temperature of 20-30°C. A mild and stable temperature range helps to reduce the stress caused by the processing, ensuring that the crystal is less prone to cleavage and causes less damage.

[0025] According to a preferred embodiment of the present invention, in steps (1)-(3), the residual Al2O3 powder on the mercurous halide crystal needs to be rinsed with a mixed solution of ethanol and petroleum ether, wiped clean with a silk cloth and dried before polishing in the next step, which can help reduce scratches on the crystal surface and improve the surface quality. The volume ratio of ethanol to petroleum ether in the mixed solution is 95:5.

[0026] According to a preferred embodiment of the present invention, steps (1), (2), and (3) must be performed sequentially, with appropriate times selected to ensure the removal of damage caused by the previous polishing step. The Al2O3 particle size and polishing time in each step of the present invention can help to fully eliminate the damage caused by the previous processing step, ultimately significantly improving the surface finish of the crystal and suppressing the generation of cleavage microstripes inside the crystal.

[0027] The technical features and beneficial effects of this invention are as follows:

[0028] The inventors of this application have discovered for the first time in their research on mercury halide crystals that traditional polishing processes cause cleavage micro-stripes to form on the (001) surface of the mercury halide crystals, and the stripe structure is neatly arranged. This is mainly due to the mechanical stress introduced by subsequent processing (cutting, polishing). Improper processing techniques can cause significant damage to the crystal, making it prone to cleavage along the surface. <110> Cleavage occurs due to directional changes. Therefore, to address the aforementioned problems and suppress the micro-stripes within the mercurous halide crystal, thereby improving the quality of the processed crystal, the inventors of this application conducted extensive research on polishing processes. They determined the relationship between the processing technology and the internal cleavage of the mercurous halide crystal, and employed an optimized polishing process. By controlling process parameters such as Al2O3 particle size and polishing time, they suppressed the micro-stripes within the mercurous halide crystal, thus improving the quality of the processed crystal. Compared with existing technologies, the superior effects of this invention are as follows:

[0029] 1. This invention optimizes the processing technology by using a step-by-step polishing method with Al2O3 polishing slurries of various specific particle sizes to process mercurous halide crystals. This significantly suppresses cleavage micro-stripes within the mercurous halide crystals, noticeably reduces the full width at half maximum (FWHM) of the X-ray single-crystal rocking curve, significantly eliminates crystal defects, and greatly improves crystallinity. The step-by-step polishing method provides a simple and effective measure for improving the performance of processed crystals in practical applications. In each polishing step of this invention, the Al2O3 particle size must be controlled within the range specified in this invention. If the Al2O3 particle size is too small or too large, it will not suppress the internal cleavage of the mercurous halide crystals, reduce damage to the crystal, and effectively eliminate crystal defects.

[0030] 2. The optimized processing technology of this invention uses Al2O3 polishing slurry with a specific solvent composition for step-by-step polishing. The inventors of this application have discovered through extensive research that using ethylene glycol as a specific solvent as the polishing slurry solvent can effectively suppress the internal cleavage of mercurous halide crystals. Furthermore, it is not easily volatile, and its temperature changes little during the polishing process, so it does not react with mercurous halide crystals. In contrast, water, methanol, and ethanol, which are commonly used water-based solvents, easily react with mercurous halide crystals or penetrate into the crystals. Moreover, their temperature changes significantly during the polishing process, which can easily lead to crystal cracking.

[0031] 3. The method of the present invention can effectively suppress the cleavage stripes generated on the (001) surface of mercury halide crystals during processing, and the crystallinity of the crystal surface is significantly improved. The processed crystals in different directions have high-quality surfaces and can be used for high-performance infrared polarizing / acoustic-optic devices. At the same time, the present invention is simple and convenient to operate and has low cost. Attached Figure Description

[0032] Figure 1 These are photographs of large-size Hg2Cl2 (a) and Hg2Br2 (b) single crystals grown by the transparent PVT method in this invention.

[0033] Figure 2 This is an optical microscope image of the (001) surface of the mercurous chloride wafer obtained in Example 1.

[0034] Figure 3 It is the half-peak width of the rocking curve of the mercurous chloride wafer obtained in Example 1.

[0035] Figure 4 These are crystal photographs of Hg2Cl2 (a) obtained by polishing in Example 1 and Hg2Br2 (b) obtained by polishing in Example 2.

[0036] Figure 5 This is an optical microscope image of the (001) surface of the mercurous chloride crystal in Example 1 after three-step polishing treatment.

[0037] Figure 6 It is the half-peak width of the rocking curve of the mercurous chloride crystal after three-step polishing in Example 1.

[0038] Figure 7 This is an optical microscope image of the (001) surface of a mercurous chloride crystal that has undergone three-step polishing in Comparative Example 1.

[0039] Figure 8 These are comparative photos of mercurous bromide wafers before and after polishing when methanol was used as a solvent in Comparative Example 2.

[0040] Figure 9 This is a photograph of a mercurous chloride wafer processed with a polishing solution using ethanol as a solvent, as shown in Comparative Example 2.

[0041] Figure 10 This is an optical microscope image of the (001) surface of a mercurous chloride crystal after two-step polishing, as shown in Comparative Example 3.

[0042] Figure 11 It is a prism device processed using the polishing process of Embodiment 1 in this invention. Detailed Implementation

[0043] The present invention will be further described below with reference to the embodiments and accompanying drawings, but this is not intended to limit the scope of protection of the present invention. Any aspects not described in detail in the embodiments are existing technologies in the art.

[0044] All raw materials and equipment used in the examples are conventional and can be purchased commercially.

[0045] The corundum grinding disc used in the embodiment is cylindrical and made of white corundum (Al2O3); the polishing damping cloth used is SH-10, with a thickness of 1.0mm, a hardness of 65JIS-A, and is made of polyurethane, a common commercially available product.

[0046] The mercury halide crystals used in the examples were grown using the PVT method. Images of the resulting large-size Hg₂Cl₂ and Hg₂Br₂ crystals are shown below. Figure 1 As shown, the dimensions of the obtained large-sized Hg2Cl2 are Ф50×40mm. 3 .

[0047] Example 1

[0048] A processing method for suppressing the generation of microstripes during the processing of mercurous chloride crystals, comprising the following steps:

[0049] (1) Treatment of mercurous chloride crystals

[0050] Using a YX-2 type X-ray orientation instrument to examine a Ф50×40mm... 3 Large-sized mercurous chloride crystals were oriented. During crystal orientation, the two mutually perpendicular natural planes (110) at the end of the crystal were first calibrated. Then, the (001) plane of the mercurous chloride crystal was determined using the relationship that the (001) plane of the crystal is mutually perpendicular to the two mutually perpendicular natural planes. Finally, based on the determined (110) and (001) diffraction planes, the other diffraction planes of the mercurous chloride crystal could be determined using angular relationships. After the crystal orientation was completed, the mercurous chloride crystal was cut using an STX-202A diamond wire cutter to obtain a 6×6×5mm crystal. 3 The mercurous chloride wafers were cut using a relatively gentle process: a cutting speed of 0.05 mm / min and a rotation speed of 150 r / min, to minimize damage to the mercurous chloride crystals. The resulting wafers were observed under a transmission optical microscope in transmission mode, and the results are as follows... Figure 2 As shown: the (001) surface of the crystal exhibits numerous scratches and longitudinal striations, with the striations arranged neatly and evenly spaced; high-resolution XRD testing of the wafer was performed using a Bruker-AXS D5005HR, and the results are as follows. Figure 3 As shown: the peak shape of the rocking curve is asymmetrical, the half-peak width is very large (1.58°), and the crystal surface quality is poor.

[0051] (2) Three-step polishing process

[0052] The mercurous chloride crystals obtained in step (1) were subjected to a three-step polishing process, with the polishing temperature controlled at 25±5℃. First, a polishing solution with an Al2O3 concentration of 0.08 g / mL was prepared by mixing coarse-grained (14 μm) Al2O3 and ethylene glycol, and the Hg2Cl2 crystals were ground on a corundum grinding disc for 15 min. Then, a polishing solution with an Al2O3 concentration of 0.03 g / mL was prepared by mixing medium-grained (1 μm) Al2O3 and ethylene glycol, and the Hg2Cl2 sample from the previous step was polished on a polishing damping cloth. The first polishing session lasted 10 minutes to eliminate scratches introduced by grinding. Finally, a polishing slurry with an Al2O3 concentration of 0.03 g / mL, prepared by mixing fine-grained (0.05 μm) Al2O3 and ethylene glycol, was used to perform precision polishing on the polishing damping cloth for 10 minutes to remove the pitted depressions left on the Hg2Cl2 surface and bring the crystal to the required surface quality. After each polishing session, the wafer was cleaned with a mixed solution of ethanol and petroleum ether (ethanol: petroleum ether = 95:5 (v / v)), wiped clean with a silk cloth, and dried.

[0053] The photograph of the mercurous chloride crystals obtained in this embodiment is shown below. Figure 4 As shown; the wafer after the above treatment was observed in transmission mode under an optical microscope, and the results are as follows. Figure 5 As shown, scratches on the (001) surface of the crystal are significantly reduced, and the number and depth of microstripes are greatly suppressed. High-resolution XRD testing of the wafer was performed using a Bruker-AXS D5005HR, and the results are as follows... Figure 6 As shown, the rocking curve of the polished mercurous chloride crystal has a symmetrical peak shape, no splitting, and the full width at half maximum (FWHM) decreases to 0.27°, indicating a significant improvement in the crystallinity of the crystal surface.

[0054] Example 2

[0055] A processing method for suppressing the generation of microstripes during the processing of mercurous bromide crystals is the same as described in Example 1, except that mercurous chloride single crystals are replaced with mercurous bromide crystals. A photograph of the resulting mercurous bromide crystal is shown below. Figure 4 As shown.

[0056] Example 3

[0057] A processing method for suppressing the generation of microstripes during the processing of mercurous iodide crystals is the same as that described in Example 1, except that mercurous chloride single crystals are replaced with mercurous iodide crystals.

[0058] Comparative Example 1

[0059] A processing method for suppressing the generation of microstripes during the processing of mercurous chloride crystals is described in Example 1, except that the particle size of Al2O3 used in each polishing step is different from that of this invention. Specifically, the method is as follows: First, a polishing slurry with an Al2O3 concentration of 0.08 g / mL is prepared by mixing coarse-grained (30 μm) Al2O3 and ethylene glycol, and the Hg2Cl2 crystal is ground on a corundum grinding disc for 15 min. Then, a polishing slurry with an Al2O3 concentration of 0.03 g / mL is prepared by mixing medium-grained (15 μm) Al2O3 and ethylene glycol, and the Hg2Cl2 sample from the previous step is polished a second time on a polishing damping cloth for 10 min. Finally, a polishing slurry with an Al2O3 concentration of 0.03 g / mL is prepared by mixing fine-grained (0.05 μm) Al2O3 and ethylene glycol, and the sample is precision polished on a polishing damping cloth for 10 min.

[0060] Figure 7 This is an optical microscope image of the mercurous chloride crystal obtained in this comparative example. It can be seen that at this Al₂O₃ particle size, surface scratches cannot be removed, and cleavage fringes are not significantly suppressed.

[0061] Comparative Example 2

[0062] We also explored the effectiveness of polishing slurries using aqueous media such as methanol and ethanol as solvents for processing mercurous halide crystals. Hg2Br2 crystals were processed using the three-step polishing method described in Example 1, except that the polishing solvent was replaced with a methanol solution. The results are as follows: Figure 8 As shown, by Figure 8 It can be seen that the Hg2Br2 crystal darkened significantly after polishing in a methanol environment, indicating that the methanol solution had penetrated into the crystal, which severely affected the crystal's transmittance. Therefore, this aqueous medium is not suitable as a polishing solvent for mercurous halide crystals.

[0063] Figure 9 The image shows the effect of using a polishing solution with methanol replaced by ethanol as the solvent to process mercurous halide crystals under the same conditions as above. In this case, due to the volatility of ethanol, the temperature changes significantly during the polishing process, making the crystal extremely prone to cleavage and cracking, which affects the light transmission performance of the crystal and makes it unsuitable for subsequent processing of polarizing and acousto-optic devices. Therefore, this aqueous medium is also unsuitable as a polishing solvent for mercurous halide crystals.

[0064] Comparative Example 3

[0065] We also conducted comparative experiments on different polishing steps to suppress micro-stripes in the processing of mercurous chloride crystals, using only a two-step polishing method, which lacked a third precision polishing step.

[0066] Figure 10This is an optical microscope image of a mercury halide crystal that underwent a two-step polishing method (lacking a third polishing step) as a comparative example. It can be seen that this insufficient polishing method cannot remove surface scratches, and cleavage fringes are not significantly suppressed.

[0067] Experimental Example 1

[0068] Figure 11 The image shows a prism device based on Hg2Cl2 crystal using the polishing method of this invention. The three-step polishing method of this invention was used for precision processing, removing most of the surface scratches. The advantages of the three-step polishing method compared to other polishing methods are: the Al2O3 particle size and polishing time in each step of this invention can effectively eliminate damage and scratches caused by the previous processing step, thereby significantly improving the surface smoothness of the crystal and suppressing the generation of cleavage micro-stripes inside the crystal. The prism was tested for extinction ratio using lasers with wavelengths of 633nm and 1064nm (the test accuracy of this method has an error of no more than 5%). The light source spot size used in this test was 6mm (theoretically, the spot size is about 80% of the aperture of the crystal under test). The average values ​​obtained from multiple experiments were: 10000:1@633nm; 18000:1@1064nm, reflecting the superiority of the three-step polishing method for processing Hg2Cl2 crystal.

Claims

1. A processing method for suppressing the generation of microstripes during the processing of mercurous halide crystals, comprising the following steps: (1) A coarse-grained Al2O3 polishing slurry with a particle size of 10-20 μm is used to grind the mercury halide crystal to remove the surface damage layer caused by the cutting of the mercury halide; the coarse-grained Al2O3 polishing slurry is obtained by dispersing coarse-grained Al2O3 in ethylene glycol, and the mass ratio of the coarse-grained Al2O3 to the volume of ethylene glycol is 0.01-0.1 g: 1 mL; the grinding time is 10-20 min; (2) The mercurous halide sample obtained in step (1) is polished a second time using a medium-particle size Al2O3 polishing slurry with a particle size of 0.5-3 μm to eliminate the scratches introduced by grinding; the medium-particle size Al2O3 polishing slurry is obtained by dispersing medium-particle size Al2O3 in ethylene glycol, and the mass ratio of the medium-particle size Al2O3 to the volume of ethylene glycol is 0.01-0.05 g: 1 mL; the time for the second polishing is 10-20 min; (3) The mercury halide sample obtained in step (2) is precisely polished using a fine-particle Al2O3 polishing slurry with a particle size of 0.01-0.1 μm to remove the pitted depressions left on the surface of the mercury halide crystal, thus completing the processing of the mercury halide crystal; the fine-particle Al2O3 polishing slurry is obtained by dispersing fine-particle Al2O3 in ethylene glycol, and the mass ratio of the medium-particle Al2O3 to the volume of ethylene glycol is 0.01-0.05 g: 1 mL; the precision polishing time is 10-20 min; The processing in steps (1)-(3) will control the temperature at 20-30℃.

2. The process of claim 1 wherein the process is the production of halide mercury (I) crystals. The mercurous halide crystal in step (1) is a mercurous chloride crystal, a mercurous bromide crystal, or a mercurous iodide crystal; the mercurous halide crystal is a large-size mercurous halide bulk crystal grown by the PVT method, which is then oriented and cut. The orientation steps are as follows: A YX-2 type X-ray orientation instrument is used to orient a large-size mercurous halide crystal. During the crystal orientation process, the orientation calibration is first performed on the two mutually perpendicular natural planes 110 at the end of the crystal. Then, the 001 plane of the mercurous halide crystal is determined by the relationship that the 001 plane of the crystal is perpendicular to both of the two mutually perpendicular natural planes. Finally, based on the determined 110 and 001 diffraction planes, the other diffraction planes of the mercurous halide crystal can be determined by the angle relationship. The cutting steps are as follows: based on the completed crystal orientation, a large-size mercury halide bulk crystal is cut using an STX-202A diamond wire cutting machine to obtain mercury halide crystals, wherein the cutting speed is 0.05-0.1 mm / min and the rotation speed is 150-200 r / min.

3. The method of claim 1 wherein the method of inhibiting the formation of microstriae in the processing of a mercurous halide crystal is characterized by, In step (1), the particle size of coarse Al2O3 is 14 μm; the mass ratio of the coarse Al2O3 to the volume of ethylene glycol is 0.05-0.1 g: 1 mL.

4. The processing method for suppressing the generation of microstripes during the processing of mercurous halide crystals according to claim 1, characterized in that, The grinding time in step (1) is 15 minutes; the grinding is performed on a corundum grinding disc.

5. The processing method for suppressing the generation of microstripes during the processing of mercurous halide crystals according to claim 1, characterized in that, In step (2), the particle size of medium-sized Al2O3 is 1 μm.

6. The processing method for suppressing the generation of microstripes during the processing of mercurous halide crystals according to claim 1, characterized in that, The time for the secondary polishing in step (2) is 10 minutes.

7. The processing method for suppressing the generation of microstripes during the processing of mercurous halide crystals according to claim 1, characterized in that, In step (3), the particle size of fine Al2O3 is 0.05 μm.

8. The processing method for suppressing the generation of microstripes during the processing of mercurous halide crystals according to claim 1, characterized in that, The precision polishing time in step (3) is 10 minutes.

9. The processing method for suppressing the generation of microstripes during the processing of mercurous halide crystals according to claim 1, characterized in that, The polishing process in steps (2) and (3) is carried out on the polishing damping cloth.

10. The processing method for suppressing the generation of microstripes during the processing of mercurous halide crystals according to claim 1, characterized in that, In steps (1)-(3), the residual Al2O3 powder on the mercury halide crystal needs to be rinsed with a mixed solution of ethanol and petroleum ether, wiped clean with a silk cloth and dried before polishing in the next step. The volume ratio of ethanol to petroleum ether in the mixed solution is 95:5.

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