Method for detecting defects in transparent ceramics
By combining optical microscopy and transmission electron microscopy, and treating samples with gold and carbon layers, the problem of pinpoint detection of defect types and composition in transparent ceramics was solved, enabling rapid and accurate defect analysis and guiding the optimization of the preparation process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SONGSHAN LAKE MATERIALS LAB
- Filing Date
- 2023-12-22
- Publication Date
- 2026-05-19
AI Technical Summary
Existing technologies cannot accurately pinpoint the types and composition of defects in transparent ceramics, which affects the optimization of their optical performance.
The location of defects is determined by optical microscopy, and the refractive index and electron energy loss spectrum of the defects are analyzed by transmission electron microscopy. The samples are then treated with gold and carbon layers to achieve point detection of transparent ceramics.
It enables rapid and accurate localization detection of defects in transparent ceramics, improving detection speed and accuracy. It can analyze defect types and compositions, and guide the optimization of preparation processes.
Smart Images
Figure CN117761063B_ABST
Abstract
Description
Technical Field
[0001] This application relates to a method for detecting defects in transparent ceramics. Background Technology
[0002] Transparent ceramics possess excellent optical properties, high thermal conductivity, and stable physical and chemical properties, and have been widely used in laser enhancement media, fluorescent ceramics, scintillators, and other fields. In particular, rare-earth-doped transparent ceramics exhibit excellent optical properties and have enormous market potential in the fabrication of high color rendering index white LEDs, ultrathin optical lenses, and photochromic materials.
[0003] However, transparent ceramic microstructures typically contain numerous light scattering sources, such as pores, grain boundaries, and impurities, which contribute to birefringence and affect the optical properties of transparent ceramics. Characterizing the microstructure and properties of these scattering sources is crucial for optimizing the fabrication process of transparent ceramics.
[0004] Currently, conventional detection methods include optical microscopy, scanning electron microscopy, and CT scans. However, there is currently no solution to accurately pinpoint the type and composition of defects. Summary of the Invention
[0005] The purpose of this application is to provide a method for detecting defects in transparent ceramics, which can pinpoint the defect type and defect composition of transparent ceramics.
[0006] The first aspect of this application provides a method for detecting defects in transparent ceramics, comprising:
[0007] An optical microscope was used to examine the first sample made of transparent ceramic to determine the location of defects;
[0008] Based on the location of the defect, the region containing the defect is extracted from the first sample to obtain the second sample;
[0009] The second sample was analyzed using transmission electron microscopy; the type and composition of defects were determined based on the refractive index and electron energy loss spectrum of the second sample.
[0010] Transparent ceramics include: oxide ceramics, fluoride ceramics, oxynitride ceramics, oxysulfide ceramics, sulfide, selenide and telluride ceramics, etc.
[0011] In the above technical solution, by adopting the above detection method, the type and composition of defects can be determined at specific points based on the refractive index and electron energy loss spectrum of transparent ceramics.
[0012] Currently, it is difficult to determine the type and composition of defects in transparent ceramics at specific locations. This application provides a simple and accurate method for obtaining the type and composition of defects in transparent ceramics, which has guiding significance for the preparation process of transparent ceramics.
[0013] This method boasts advantages such as high detection speed, high accuracy, and the ability to pinpoint and deeply analyze the composition of defects in transparent ceramics. Compared to conventional methods that directly use scanning electron microscopy (SEM) or CT scans to detect defects in transparent ceramics, the method presented in this application has the advantage of being able to scan defects in a directional manner and analyze the defect type and elemental distribution. Directly using SEM to detect defects in transparent ceramics cannot pinpoint and analyze the defect type and category; directly using CT scans to detect defects in transparent ceramics cannot pinpoint and analyze whether the defect is a cavity or elemental phase separation.
[0014] In other embodiments of this application, the barium-zirconium-magnesium-tantalum oxide ceramic system includes: Ba(Zr) x Mg y Ta z O3:A1, where x+y+z=1, 4x+2y+5z=4, z=2y; A1 includes at least one of Pr, Yb, Re or Pr elements;
[0015] Optionally, the oxide system ceramic includes: Y3Al5O 12 :A, wherein A includes at least one of the elements Pr, Yb, Re, or Pr;
[0016] Optionally, the fluoride system ceramic includes: CaF2;
[0017] Optionally, the oxynitride system ceramic includes: AlON;
[0018] Optionally, the oxysulfide system ceramic includes: Gd2O2S;
[0019] Optionally, the sulfide, selenide, and telluride ceramic system includes: ZnS, ZnSe, and GdTe.
[0020] In other embodiments of this application, the transparent ceramic is Ba(Zr) 0.16 Mg 0.28 Ta 0.56 )O3.
[0021] In other embodiments of this application, transmission electron microscopy is used to analyze the second sample, including:
[0022] The second sample was analyzed using TEM and EELS; the refractive index and electron energy loss spectrum of the transparent ceramic were obtained; the defect type was determined based on the electron energy loss spectrum of the transparent ceramic, and the defect composition was determined in combination with the refractive index.
[0023] In other embodiments of this application, the types of defects include at least one of: pores or elemental phase separation.
[0024] In other embodiments of this application, extracting the defective region from the first sample to obtain a second sample includes:
[0025] After extracting the defective area from the first sample, a gold plating layer and a carbon layer are formed in the area to obtain the second sample.
[0026] In other embodiments of this application, the thickness of the gold plating layer is 15nm to 25nm;
[0027] Optionally, the thickness of the carbon layer is 1 μm to 3 μm.
[0028] In other embodiments of this application, a first sample is made of transparent ceramic, comprising:
[0029] Transparent ceramics are made to a thickness of 0.5mm to 1.5mm;
[0030] Optionally, the surface roughness is below 5 nm.
[0031] In other embodiments of this application, an optical microscope is used to inspect a first sample made of transparent ceramic to determine the location of defects, including:
[0032] After cleaning the first sample, it was examined under light at a range of 40° to 50°, and then placed under an optical microscope to determine the distribution of defects.
[0033] In other embodiments of this application, the length of the region is 15μm to 25μm;
[0034] Optionally, the width of the region is 1μm to 3μm.
[0035] Secondly, this application provides a method for detecting defects in transparent ceramics, comprising:
[0036] An optical microscope was used to examine the first sample made of transparent ceramic to determine the location of defects;
[0037] The first sample was plated with gold to obtain the second sample, and the defects on the surface of the second sample were detected by scanning electron microscopy.
[0038] Based on the location of the defect, the region containing the defect is extracted from the second sample to obtain the third sample;
[0039] The third sample was analyzed using transmission electron microscopy; the type and composition of defects were determined based on the refractive index and electron energy loss spectrum of the third sample.
[0040] Transparent ceramics include: oxide ceramics, fluoride ceramics, oxynitride ceramics, oxysulfide ceramics, sulfide, selenide and telluride ceramics, etc. Attached Figure Description
[0041] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0042] Figure 1 An image of the transparent ceramic of Example 1 examined under light at a 45° angle is shown;
[0043] Figure 2 The image shows a defect image of transparent ceramic under an optical microscope in Example 1;
[0044] Figure 3 The SEM-EDS detection image of Example 1 is shown;
[0045] Figure 4 The FIB sample preparation diagram of Example 1 (third sample) is shown;
[0046] Figure 5 The TEM-EELS detection pattern of Example 1 is shown;
[0047] Figure 6 Calculation of refractive index before and after the defect;
[0048] Figure 7 Theoretical values of BZMT refractive index for different zirconium contents;
[0049] Figure 8 The SEM image of Comparative Example 1 is shown;
[0050] Figure 9 The CT scan image of Comparative Example 2 is shown. Detailed Implementation
[0051] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.
[0052] Therefore, the following detailed description of the embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0053] This application provides a method for detecting defects in transparent ceramics, including:
[0054] An optical microscope was used to examine the first sample made of transparent ceramic to determine the location of defects;
[0055] Based on the location of the defect, the region containing the defect is extracted from the first sample to obtain the second sample;
[0056] The second sample was analyzed using transmission electron microscopy; the type and composition of defects were determined based on the refractive index and electron energy loss spectrum of the second sample.
[0057] Transparent ceramics include: oxide ceramics, fluoride ceramics, oxynitride ceramics, oxysulfide ceramics, sulfide, selenide and telluride ceramics, etc.
[0058] In the above technical solution, by adopting the above detection method, the type and composition of defects can be determined based on the refractive index and electron energy loss spectrum of transparent ceramics.
[0059] Currently, it is difficult to directly determine the type and composition of defects in transparent ceramics. This application provides a simple and accurate method for obtaining the type and composition of defects in transparent ceramics, which has great guiding significance for the preparation process of transparent ceramics.
[0060] This method boasts advantages such as high detection speed, high accuracy, and the ability to deeply analyze the composition of defects in transparent ceramics. Compared to conventional methods that directly use scanning electron microscopy (SEM) or CT scans to detect defects in transparent ceramics, the method presented in this application has the advantage of being able to scan defects in a targeted manner and analyze the defect type and elemental distribution. Directly using SEM to detect defects in transparent ceramics cannot provide targeted analysis of defect type and category; directly using CT scans cannot provide targeted analysis to determine whether the defect is a cavity or elemental phase separation.
[0061] Furthermore, in some embodiments of this application, the method for detecting defects in transparent ceramics includes:
[0062] Step S1: Use an optical microscope to examine the first sample made of transparent ceramic to determine the location of defects.
[0063] Furthermore, in some embodiments of this application, the first sample is made of transparent ceramic, including:
[0064] Transparent ceramics are made to a thickness of 0.5mm to 1.5mm.
[0065] Furthermore, in some embodiments of this application, the first sample is made of transparent ceramic, including:
[0066] Transparent ceramics are made to a thickness of 0.6 mm to 1.4 mm.
[0067] Exemplarily, in some embodiments of this application, a first sample is made of transparent ceramic, comprising:
[0068] Transparent ceramics are made with thicknesses of 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, or 1.4mm.
[0069] Furthermore, in some embodiments of this application, the surface roughness of the first sample made of transparent ceramic is less than 5 nm.
[0070] For example, in some embodiments of this application, the surface roughness of the first sample made of transparent ceramic is 0.2nm, 0.5nm, 1nm, 2nm, 3nm, 4nm or 5nm.
[0071] The aforementioned thickness and roughness ranges are well-suited for optical microscopy observation of transparent ceramics, enabling rapid and accurate localization of impurities and defects in transparent ceramics, thus providing a favorable guarantee for subsequent scanning electron microscopy sampling.
[0072] Furthermore, exemplarily, in some embodiments of this application, the transparent ceramic blank is thinned and polished on both sides to a thickness of 1 mm and a surface roughness of less than 1 nm, and then the ceramic to be tested is cleaned and dried to remove all moisture.
[0073] Furthermore, in some embodiments of this application, an optical microscope is used to inspect a first sample made of transparent ceramic to determine the location of defects, including:
[0074] After cleaning the first sample, it was examined under light at a range of 40° to 50°, and then placed under an optical microscope to determine the distribution of defects.
[0075] Exemplary, in some embodiments of this application, the above-mentioned determination of defect location includes:
[0076] After cleaning the first sample, inspect it under light at 40°, 41°, 42°, 43°, 44°, 45°, 46°, 47°, 48°, 49° or 50°, and then place it under an optical microscope to determine the defect distribution.
[0077] The above-mentioned inspection at 40° to 50° of light is beneficial for the optical microscope to quickly and accurately locate defects in transparent ceramics.
[0078] Exemplary, in some embodiments of this application, an optical microscope is used to examine a first sample made of transparent ceramic, such as... Figure 2 As shown.
[0079] from Figure 2As can be seen from the image, the dot-like clusters are impurities and defects in the transparent ceramic. By combining SEM scanning, the coordinates of the defects can be further confirmed and marked. Finally, the defects can be extracted in a directional manner to quickly locate the defect positions in the transparent ceramic.
[0080] Step S2: Based on the defect location, extract the region containing the defect from the first sample to obtain the second sample.
[0081] Furthermore, in some embodiments of this application, extracting the defective region from the first sample to obtain a second sample includes:
[0082] After extracting the defective area from the first sample, a gold plating layer and a carbon layer are formed in the area to obtain the second sample.
[0083] Furthermore, in some embodiments of this application, the thickness of the gold plating layer is 15nm to 25nm.
[0084] For example, in some embodiments of this application, the thickness of the gold plating layer is 15nm, 16nm, 17nm, 18nm, 19nm, 20nm, 21nm, 22nm, 23nm, 24nm or 25nm.
[0085] Ceramic materials have poor electrical conductivity. By forming a gold-plated layer with a thickness of 15nm to 25nm on the surface of ceramic samples, the conductivity of the samples can be improved, thereby improving the quality and resolution of scanning electron microscope (SEM) images. This makes them more suitable for SEM and transmission electron microscope (TEM) inspections, enabling accurate and rapid detection of surface and internal defects and components.
[0086] Furthermore, in some embodiments of this application, the aforementioned gold plating layer can be achieved through a vacuum plating process.
[0087] For example, in some embodiments of this application, a Leica EMACE200 vacuum coating instrument is used to coat the sample surface with gold 20 nm for subsequent detection.
[0088] For example, in some embodiments of this application, samples are sent into the sample chamber of a field emission environmental scanning electron microscope (FE-ThermoFisher Quattro ESEM) for surface morphology and X-ray energy dispersive spectroscopy analysis of elemental distribution, which can quickly detect surface defects and composition.
[0089] Furthermore, in some embodiments of this application, the thickness of the carbon layer is 1 μm to 3 μm.
[0090] For example, in some embodiments of this application, the thickness of the carbon layer is 1 μm, 1.1 μm, 1.2 μm, 1.5 μm, 1.8 μm, 2 μm, 2.2 μm, 2.5 μm, 2.8 μm or 3 μm.
[0091] Transparent ceramics are polycrystalline, high-entropy materials. TEM can be used to statistically analyze sample grain size and characterize grain bonding and defect distribution at the atomic scale. The aforementioned method of creating a carbon layer of 1 μm to 3 μm thickness on the ceramic surface is well-suited for TEM inspection, enabling rapid and accurate measurement of the effects of different impurities and defects on the refractive index of transparent ceramics. This provides guidance for optimizing the preparation process to reduce impurities and improve ceramic transparency.
[0092] Furthermore, in some embodiments of this application, the carbon layer described above can be prepared using a vapor deposition process.
[0093] Furthermore, in some embodiments of this application, the length of the aforementioned region is 15μm to 25μm. Exemplarily, in some embodiments of this application, the length of the aforementioned region is 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, 21μm, 22μm, 23μm, 24μm, or 25μm.
[0094] Furthermore, in some embodiments of this application, the width of the region is 1μm to 3μm. For example, in some embodiments of this application, the width of the region is 1μm, 1.1μm, 1.2μm, 1.5μm, 1.8μm, 2μm, 2.2μm, 2.5μm, 2.8μm, or 3μm.
[0095] Further, exemplary, in some embodiments of this application, a transparent ceramic preform is prepared using a focused ion beam (FIB, Helios G4 UX) system. First, the location for extracting the TEM sample is determined using an optical microscope. Then, a point-to-point FIB sample preparation is performed. Following a 20nm gold plating operation, a carbon (C) protective layer of approximately 20μm × 2μm × 2μm (length × width × height) is deposited on the sample preparation area within the FIB system. Subsequently, the area around and bottom of the sample preparation area is hollowed out to provide sufficient space for sample extraction (e.g., ...). Figure 4 As shown, the sample was extracted and transferred to a copper grid using a platinum (Pt) needle. The sample was then thinned on both sides using a gallium (Ga) ion beam with gradually varying voltage and beam current until the thickness reached approximately tens of nanometers, meeting the requirements for transmission electron microscopy (TEM) characterization.
[0096] Step S3: Analyze the second sample using transmission electron microscopy; determine the type and composition of defects based on the refractive index and electron energy loss spectrum of the second sample.
[0097] Furthermore, in some embodiments of this application, the types of defects include at least one of: pores or elemental phase separation.
[0098] Furthermore, in some embodiments of this application, transmission electron microscopy is used to analyze the second sample, including:
[0099] TEM-EELS was used for detection and analysis.
[0100] Furthermore, in some embodiments of this application, transmission electron microscopy (TEM) is used to analyze the second sample, including TEM and EELS analysis. First, the grain size, grain bonding, and impurity distribution of the transparent ceramic sample are statistically analyzed using TEM, and elemental segregation and atomic structure at grain boundaries can be characterized. The electron energy loss spectrum of the transparent ceramic is collected, and the refractive index is analyzed. Here, based on the (low-energy) electron energy loss spectrum of the transparent ceramic, the influence of impurities and defects on transparency is analyzed and classified according to the Kramers-Kronig relationship, and further defect composition is characterized using EDS and atomic structure. For example, we found unsintered tannin oxide (with different degrees of sintering) in BZMT transparent ceramics prepared at different sintering temperatures, and the impurity size decreased with increasing sintering temperature, such as... Figure 3 As shown, EELS characterization analysis revealed that different impurities and defects have varying effects on the transparency of the material, meaning that different impurities have different refractive abilities. Furthermore, by comparing samples under different conditions, the microscopic mechanisms of the preparation process can be analyzed, thus providing more directional guidance for ceramic fabrication processes. Figure 5 As shown, the HAADF image (a morphological imaging mode for (S)TEM analysis—high-angle annular dark-field image-scanning transmission electron image) first determines the location of the defect, as shown in the image. Figure 5 (a) HAADF image of intergranular defects in BZMT (arrows indicate EELS and EDS scanning directions). Further, we used electron beam scanning to obtain... Figure 5 (b) The electron energy loss spectrum obtained by scanning the defects in Figure (a) through the electron beam. Further energy loss is obtained through energy spectrum calculations. Figure 5 (c) Non-negative matrix decomposition of the EELS data in Figure (b) can quickly analyze components affecting transparency in the material, such as impurities, defects, and grain boundaries. Then, a structure like... Figure 5 (d) and (c) are the low-energy energy loss spectra of the bulk and impurity components. The changes in the proportion of each element in the material with the scanning direction are also obtained. Figure 5 As shown in (e). Finally, we scanned the typical grain boundary atomic structure HAADF images of BZMT materials, as shown in (e). Figure 5 As shown in (fg), different atomic arrangements can be observed, thus determining the composition of the defects. Finally, the refractive index and electron energy loss spectrum of the transparent ceramic are obtained; based on the acquired electron energy loss spectrum and Kramers-Kronig relationship, the defect type, defect refractive index, and compositional variations can be determined.
[0101] Furthermore, in some embodiments of this application, transparent ceramics include: oxide system ceramics, fluoride system ceramics, oxynitride system ceramics, oxysulfide system ceramics, sulfide, selenide and telluride system ceramics, etc.
[0102] Furthermore, in some embodiments of this application, the barium-zirconium-magnesium-tantalum oxide ceramic system includes: Ba(Zr) x Mg y Ta z O3:A1, where x+y+z=1, 4x+2y+5z=4, z=2y; A1 includes at least one of Pr, Yb, Re or Pr elements.
[0103] Exemplary, in some embodiments of this application, the above-described barium zirconium magnesium tantalum oxide system ceramic includes: Ba(Zr) 0.16 Mg 0.28 Ta 0.56 O3、Ba(Zr) 0.16 Mg 0.28 Ta 0.56 At least one of O3:Pr.
[0104] In some embodiments of this application, the above-mentioned Ba(Zr) x Mg y Ta z O3:Al material can be prepared using the method disclosed in Chinese patent CN202111393200.4.
[0105] In other optional embodiments of this application, the above-mentioned Ba(Zr) x Mg y Ta z O3:Al material can also be prepared using the method disclosed in Chinese patent CN202210053431.9.
[0106] Furthermore, in some embodiments of this application, the yttrium aluminum garnet ceramic comprises: Y3Al5O 12 :A, where A includes at least one of the elements Pr, Yb, Re, or Pr.
[0107] For example, in some embodiments of this application, the barium magnesium silicon oxide system ceramic includes: Y3Al5O 12 Y3Al5O 12 :Pr、Y3Al5O 12 :Yb、Y3Al5O 12 :Re.
[0108] In the above technical solution, "A" represents a doping element; the above materials can be prepared using methods commonly used in the field.
[0109] Furthermore, in some embodiments of this application, the fluoride system ceramic includes CaF2.
[0110] Furthermore, in some embodiments of this application, the oxynitride ceramic includes AlON.
[0111] Furthermore, in some embodiments of this application, the oxygen-sulfur system ceramic includes Gd2O2S.
[0112] Furthermore, in some embodiments of this application, the sulfide, selenide, and telluride system ceramics include: ZnS, ZnSe, and GdTe.
[0113] The detection method described in this application can be used to target and detect the location and composition of defects inside transparent ceramics.
[0114] Currently, conventional characterization of transparent ceramics mainly focuses on the performance indicators of transparent ceramics under different contrast conditions at a relatively macroscopic scale, lacking a more microscopic and systematic study of impurities and defects in the material. However, further revealing the microstructure and properties of scattering sources in transparent ceramic materials is key to optimizing the preparation process of transparent ceramics. This application combines the TEM-EELS method to achieve precise imaging of defects in ceramic materials at the atomic level and to perform picometer-level structural distortion measurements. Combined with electron energy loss spectroscopy (EELS) and refractive index, it enables multi-dimensional nanoscale elemental, valence state, and spectral studies of transparent materials. This allows for targeted analysis of defect types and defect composition in transparent ceramics.
[0115] This application provides a method for detecting defects in transparent ceramics, including:
[0116] An optical microscope was used to examine the first sample made of transparent ceramic to determine the location of defects;
[0117] The first sample was plated with gold to obtain the second sample, and the defects on the surface of the second sample were detected by scanning electron microscopy.
[0118] Based on the location of the defect, the region containing the defect is extracted from the second sample to obtain the third sample;
[0119] The third sample was analyzed using transmission electron microscopy; the type and composition of defects were determined based on the refractive index and electron energy loss spectrum of the third sample.
[0120] Transparent ceramics include: oxide ceramics, fluoride ceramics, oxynitride ceramics, oxysulfide ceramics, sulfide, selenide and telluride ceramics, etc.
[0121] This method uses scanning electron microscopy to detect defects on the surface of transparent ceramics and transmission electron microscopy to analyze defects inside the transparent ceramics, thus detecting defects in transparent ceramics from different angles and providing a more complete detection of defects in transparent ceramics.
[0122] In this embodiment, other steps, such as sample preparation, can employ the same methods provided in any of the foregoing embodiments.
[0123] The features and performance of this application will be further described in detail below with reference to embodiments:
[0124] Example 1
[0125] A method for detecting defects in transparent ceramics is provided, comprising the following steps:
[0126] (a) Put Ba(Zr 0.16 Mg 0.28 Ta 0.56 The first sample was obtained by double-sided thinning and polishing of O3 transparent ceramic to a thickness of 1 mm and a surface roughness of less than 1 nm.
[0127] (b) Then check against the light at a 45° angle, such as Figure 1 As shown. The morphology and distribution of impurities and defects visible under an optical microscope are statistically analyzed, such as... Figure 2 As shown.
[0128] (c) SEM-EDS Defect Analysis:
[0129] A second sample was obtained by depositing gold to a thickness of approximately 20 nm on the surface of the first sample using a Leica EMACE200 vacuum coating system. The second sample was then sent to the sample chamber of a Thermo Fisher Quattro field emission environmental scanning electron microscope (FET) for surface morphology characterization and X-ray energy dispersive spectroscopy (EDS) analysis of elemental distribution, allowing for rapid detection of surface defects and composition. The results are as follows: Figure 3 As shown, by analyzing the surface of transparent ceramic samples obtained through different preparation processes, it can be determined that the defects in the samples differ from those in the bulk material in terms of type and composition. Figure 3 For example, under comparative conditions of different sintering temperatures, we found that in samples with higher transparency, the diameter of unsintered tannin oxide particles was small and not obvious under EDS, while in samples with lower transparency, unsintered tannin oxide particles showed clustering enrichment. Based on SEM, further targeted analysis of internal defects in the samples was conducted (e.g., Figure 5 Improve the characterization dimensions of the samples.
[0130] (d) TEM-EELS defect analysis:
[0131] The second sample was prepared using a focused ion beam (FIB, Helios G4 UX) system. First, the location for TEM sample extraction was determined using optical microscopy in step (a). Then, a fixed-point FIB sample preparation was performed. Following a 20nm gold plating operation, a carbon (C) protective layer of approximately 20μm × 2μm × 2μm (length × width × thickness) was deposited on the prepared area within the FIB system. Subsequently, the area around and bottom of the prepared region was hollowed out to provide sufficient space for sample extraction, resulting in the third sample (e.g., ...). Figure 4 (As shown). The sample was extracted and transferred to a copper grid using a platinum (Pt) needle. The sample was then thinned on both sides using a gallium ion beam with gradually varying voltage and current until the thickness reached approximately tens of nanometers, meeting the requirements for transmission electron microscopy (TEM) characterization.
[0132] Then, TEM-EELS analysis was performed on the third sample; the type and composition of defects were determined based on the refractive index and electron energy loss spectrum of the third sample.
[0133] Test results as follows Figure 5 .
[0134] from Figure 5 It can be seen that TEM and EELS analyses are used. For example... Figure 5 As shown, the HAADF image (a morphological imaging mode for TEM analysis—high-angle annular dark-field image-scanning transmission electron image) first determines the location of the defect, as follows: Figure 5 (a) HAADF image of intergranular defects in BZMT (arrows indicate EELS and EDS scanning directions). Further, we used electron beam scanning to obtain... Figure 5 (b) The electron energy loss spectrum obtained by scanning the defects in Figure (a) through the electron beam. Further energy loss is obtained through energy spectrum calculations. Figure 5 (c) Non-negative matrix decomposition of the EELS data in Figure (b) can quickly analyze components affecting transparency in the material, such as impurities, defects, and grain boundaries. Then, a structure like... Figure 5 (d) and (c) are the low-energy energy loss spectra of the bulk and impurity components. The changes in the proportion of each element in the material with the scanning direction are also obtained. Figure 5 As shown in (e). Finally, we scanned the typical grain boundary atomic structure HAADF images of BZMT materials, as shown in (e). Figure 5 As shown in (fh), different atomic arrangements can be observed, thus determining the composition of the defects. Finally, the refractive index and electron energy loss spectrum of the transparent ceramic are obtained; based on the acquired electron energy loss spectrum and the Kramers-Kronig relationship, the defect type can be determined, and the changes in defect refractive index and composition can be analyzed. (See below) Figure 6 As shown, the refractive index before and after the defect can be calculated, and then combined with... Figure 7The theoretical refractive index n of BZMT with different zirconium contents indicates that the defects are caused by insufficient zirconium content (zirconium defects).
[0135] Comparative Example 1
[0136] A method for detecting defects in transparent ceramics is provided, comprising the following steps:
[0137] (a) Put Ba(Zr 0.16 Mg 0.28 Ta 0.56 The first sample was obtained by double-sided thinning and polishing of O3 transparent ceramic to a thickness of 1 mm and a surface roughness of less than 1 nm.
[0138] (b) A carbon protective layer with a thickness of 2 μm is formed by spraying on the surface of the first sample to obtain the second sample.
[0139] (c) The second sample was placed in the sample chamber of a standard SEM, and its morphology was examined. The results are as follows: Figure 8 As shown.
[0140] from Figure 8 It can be seen that ordinary SEM can count grain size, but it cannot analyze the type and variety of defects at specific points. Due to resolution limitations, it cannot specifically analyze microscopic features such as atomic structure at grain boundaries.
[0141] Comparative Example 2
[0142] A method for detecting defects in transparent ceramics is provided, comprising the following steps:
[0143] (a) Put Ba(Zr 0.16 Mg 0.28 Ta 0.56 The first sample was obtained by double-sided thinning and polishing of O3 transparent ceramic to a thickness of 1 mm and a surface roughness of less than 1 nm.
[0144] (c) Place the first sample into the CT sample detection chamber and perform a CT scan. The detection results are as follows: Figure 9 As shown.
[0145] from Figure 9 It can be seen that although there are many voids or impurity elements inside the material, the scanned three-dimensional structure cannot pinpoint whether the defects are pores or elemental phase separation.
[0146] In summary, neither Comparative Example 1 nor Comparative Example 2 could pinpoint the defect type and defect composition of the transparent ceramics.
[0147] The solution proposed in this application can effectively identify the defect type and defect composition of transparent ceramics that cannot be precisely analyzed.
[0148] This demonstrates that, compared to common SEM and CT inspections in the field, the proposed solution has the advantages of directional defect scanning, analysis of defect types and elemental distribution, and high detection accuracy. It can perform point-to-point and qualitative analysis of defects and analyze the elemental content, atomic structure, and refractive index of different defects in transparent ceramics with high precision, thus providing significant benefits for the preparation of transparent ceramics.
[0149] The detailed description of the embodiments in this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.
Claims
1. A method for detecting defects in transparent ceramics, characterized in that, include: An optical microscope was used to examine the first sample made of transparent ceramic to determine the location of defects; Based on the location of the defect, the region containing the defect is extracted from the first sample to obtain a second sample; The second sample was analyzed using transmission electron microscopy; The type and composition of the defects are determined based on the refractive index and electron energy loss spectrum of the second sample; The transparent ceramics include: oxide system ceramics, fluoride system ceramics, oxynitride system ceramics, oxysulfide system ceramics, sulfide, selenide and telluride system ceramics; The step of extracting the region containing the defect from the first sample to obtain the second sample includes: After extracting the region containing the defect from the first sample, a gold plating layer and a carbon layer are formed in the region to obtain a second sample. The analysis of the second sample using transmission electron microscopy includes: The second sample was analyzed using TEM and EELS; the refractive index and electron energy loss spectrum of the transparent ceramic were obtained; the defect type was determined based on the electron energy loss spectrum of the transparent ceramic, and the defect composition was determined in combination with the refractive index. The types of defects include at least one of: pores or elemental phase separation.
2. The method for detecting defects in transparent ceramics according to claim 1, characterized in that, The oxide system ceramic is: Ba(Zr) x Mg y Ta z O3:A1, where x+y+z=1, 4x+2y+5z=4, z=2y; and A1 includes at least one of Pr, Yb, Re or Pr elements.
3. The method for detecting defects in transparent ceramics according to claim 1, characterized in that, The oxide system ceramic includes: Y3Al5O 12 :A, wherein A includes at least one of the elements Pr, Yb, Re, or Pr.
4. The method for detecting defects in transparent ceramics according to claim 1, characterized in that, The fluoride system ceramics include: CaF2.
5. The method for detecting defects in transparent ceramics according to claim 1, characterized in that, The oxynitride system ceramics include AlON.
6. The method for detecting defects in transparent ceramics according to claim 1, characterized in that, The oxysulfide system ceramics include: Gd2O2S.
7. The method for detecting defects in transparent ceramics according to claim 1, characterized in that, The sulfide, selenide, and telluride ceramic system includes: ZnS, ZnSe, and GdTe.
8. The method for detecting defects in transparent ceramics according to claim 1, characterized in that, The transparent ceramic is Ba(Zr) 0.16 Mg 0.28 Ta 0.56 )O3.
9. The method for detecting defects in transparent ceramics according to claim 1, characterized in that, The thickness of the gold plating layer is 15nm~25nm; The thickness of the carbon layer is 1 μm to 3 μm.
10. The method for detecting defects in transparent ceramics according to claim 1, characterized in that, The first sample, made using the transparent ceramic, comprises: Transparent ceramics are made to a thickness of 0.5mm to 1.5mm; The surface roughness is less than 5 nm.
11. The method for detecting defects in transparent ceramics according to claim 1, characterized in that, The process of using an optical microscope to inspect a first sample made of transparent ceramic to determine the location of defects includes: After cleaning the first sample, it is inspected under light at a range of 40° to 50°, and then placed under the optical microscope to determine the defect distribution.
12. The method for detecting defects in transparent ceramics according to claim 1, characterized in that, The length of the region is 15μm ~ 25μm; The width of the region is 1μm to 3μm.
13. A method for detecting defects in transparent ceramics, characterized in that, include: An optical microscope was used to examine the first sample made of transparent ceramic to determine the location of defects; The first sample was plated with gold to obtain the second sample, and the defects on the surface of the second sample were detected by scanning electron microscopy. The second sample was prepared using a focused ion beam system. First, the location of the TEM sample was located using an optical microscope. Then, a fixed-point FIB sample was prepared. After a 20nm gold plating operation on the surface, a carbon protective layer was vapor-deposited on the sample preparation area in the FIB system. Subsequently, the area around and the bottom of the sample preparation area were hollowed out to provide sufficient space for sample extraction, thus obtaining the third sample. The third sample was then analyzed using TEM-EELS. The type and composition of defects were determined based on the refractive index and electron energy loss spectrum of the third sample; The transparent ceramics include: oxide system ceramics, fluoride system ceramics, oxynitride system ceramics, oxysulfide system ceramics, sulfide, selenide and telluride system ceramics.