Method for testing element content in metal tellurium ingot based on glow discharge mass spectrometry

Abstract

The invention discloses a method for testing the content of elements in a metal tellurium ingot based on glow discharge mass spectrometry, the metal tellurium ingot is polished by white abrasive paper to obtain a flaky sample, the test surface is flat and smooth and has metallic luster, the sample preparation operation is simple, and the problem that the metal tellurium ingot cannot be directly fed in glow discharge mass spectrometry analysis can be effectively solved. The metal tellurium ingot as a sheet enters the glow discharge mass spectrometry step, impurities are not introduced into a sample, a test signal main body is a test sample, and potential impurity element pollution in the sample preparation process is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of sample analysis and detection technology, and particularly relates to a method for testing element content in metal tellurium ingot based on glow discharge mass spectrometry. BACKGROUND

[0002] Tellurium belongs to rare metals, and has different application fields with different purities. High-purity tellurium is a basic raw material metal for preparing compound semiconductor materials. Antimony telluride, cadmium telluride, bismuth telluride and other materials are often used in the fields of energy, sensing, thermoelectricity and the like, and the purity of metal tellurium needs to reach 4N or above to be used for preparing these high-end new materials. Higher-purity tellurium metal is mostly used in the semiconductor and electronic chip industries as target material products.

[0003] Metal tellurium is most commonly used for the preparation of semiconductor materials, and the purity of the raw material has a very high requirement on the semiconductor materials. The high or low of the purity of the raw material, the types and contents of impurities will directly affect important parameters such as the electrical conductivity and thermal conductivity of the finished material. Therefore, the improvement of the detection method for high-purity tellurium material has important practical significance.

[0004] There are few reports on the detection method of impurity elements in high-purity tellurium. The earliest method is to test high-purity tellurium by plasma atomic emission spectrometry. Zhang Chaoyang et al. (Zhang Chaoyang, Ma Mingyang, Su Liukun. ICP-AES determination of 11 kinds of impurity elements in high-purity tellurium. Spectroscopy Laboratory. 2005, 22(1): 134-136) and Sun Wei et al. (Sun Wei, Chen Rongyu. Research on determination of impurity elements in high-purity tellurium ingot by plasma atomic emission spectrometry. Chemical World. 2005: 266-268) both test the impurity content in tellurium ingot by plasma atomic emission spectrometry. The sample processing method is complex, some elements cannot be tested by this method, and the detection limit is high, which is not suitable for the testing of tellurium ingot of 5N and above. Wei Jianjun et al. (Wei Jianjun, Lang Chunyan, Lin Longfei, Zheng Lin, Li Jiaxuan, Vacuum distillation separation-inductively coupled plasma mass spectrometry for determination of 9 kinds of impurity elements in high-purity tellurium. Analytical Chemistry. 2013, 9(41): 1454-1457) determine some impurities in high-purity tellurium by inductively coupled plasma mass spectrometry, which also has the problems of limited detectable elements and high detection limit. The recent research work using glow discharge mass spectrometry to test high-purity tellurium was published in 2010. Rong Baiyan et al. (Rong Baiyan, Hu Zandong, Cong Shuren, Han Fuzhong, Ji Rongbin, Glow discharge mass spectrometric analysis of trace impurity elements in high-purity tellurium and cadmium, 2010, 32(4): 226-230) analyzed high-purity tellurium by glow discharge mass spectrometry, but the method re-melted the test sample, which not only easily introduced impurities into the sample, but also might cause problems such as uneven distribution of the sample.

[0005] Therefore, developing a method for detecting the content of trace impurity elements in high-purity metal tellurium ingot with simple sample preparation operation and high accuracy has practical significance. SUMMARY

[0006] The technical problem solved by the present application is to overcome the shortcomings of the prior art and provide a method for testing the content of elements in metal tellurium ingot based on glow discharge mass spectrometry, which has simple sample preparation and accurate test results.

[0007] To solve the above technical problems, the present application adopts the following technical solutions: A method for testing the content of elements in metal tellurium ingot based on glow discharge mass spectrometry, comprising the following steps: S1, polishing the cleaned metal tellurium ingot to be tested, which includes polishing the metal tellurium ingot to be tested into a sheet shape with white sandpaper, and the test surface is flat, smooth and has a metallic luster; S2, sequentially acid washing, water washing and drying the sheet-shaped sample obtained by polishing; S3, performing glow discharge mass spectrometry analysis on the dried sheet-shaped sample to obtain the content of impurity elements.

[0008] As a further improvement to the above technical solution: In step S1, the white sandpaper is a flexible white sandpaper with a mesh size of 1000-1200.

[0009] In step S2, the acid washing uses nitric acid.

[0010] In step S2, the volume fraction of nitric acid during acid washing is 15-20%, and the time is 10-15 min.

[0011] In step S2, the water washing is performed multiple times.

[0012] In step S3, the glow discharge mass spectrometry analysis sequentially includes refrigeration, vacuum pumping and sputtering, the temperature of the refrigeration is -160 to -180 DEG C, the discharge current during sputtering is 1.2-1.5 mA, the discharge voltage is 900-1000 V, and the pre-sputtering time is 15-20 min.

[0013] In step S1, the purity of the metal tellurium ingot to be tested is ≥5N.

[0014] In step S3, the glow discharge mass spectrometry analysis includes in-situ testing of the sheet-shaped sample or multiple tests of the sheet-shaped sample at the same test point.

[0015] In step S3, during the glow discharge mass spectrometry analysis, the resolution of the collected test elements is >4000, and the signal intensity is >3.0x10 -10 A.

[0016] Compared with the prior art, the method has the beneficial effects that: The method for testing element content in metal tellurium ingot based on glow discharge mass spectrometry provided by the application grinds the metal tellurium ingot by using white sandpaper, obtains a sheet-shaped sample, and the testing surface is flat, smooth and has a metallic luster, the sample preparation operation is simple, the problem that the metal tellurium ingot cannot be directly fed into the glow discharge mass spectrometry analysis can be effectively solved, the metal tellurium ingot is in a sheet shape and is fed into the glow discharge mass spectrometry analysis step, no impurities are introduced into the sample, and the main testing signal is the testing sample, so that the potential impurity element pollution in the sample preparation process is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a process flowchart of the application.

[0018] Figure 2 is a photo of the metal tellurium ingot to be tested in Example 1.

[0019] Figure 3 is a photo of the metal tellurium ingot to be tested after grinding in Example 1.

[0020] Figure 4 is a photo of the metal tellurium ingot to be tested after the glow discharge mass spectrometry analysis is completed in Example 1. DETAILED DESCRIPTION

[0021] The application will be further described in detail below. Unless otherwise specified, the instruments or materials used in the application are commercially available.

[0022] Example 1: As shown in the table, Figure 1 a method for testing element content in metal tellurium ingot based on glow discharge mass spectrometry provided by the present embodiment comprises the following steps: (1) Grinding treatment: 10.23 g of high-purity tellurium ingot with a purity of 6N5 is selected. After being cleaned by ultrasonic washing with ultrapure water, the high-purity metal tellurium ingot is ground into a sheet shape by using a flexible white sandpaper with a high mesh (1000-1200 mesh), and the testing surface of the high-purity metal tellurium ingot is ground until the processed surface is flat, smooth and has a metallic luster.

[0023] Compared with a powder sample, the sheet-shaped sample can be subjected to acid washing and pre-sputtering operations, the influence of the external environment on the surface of the block-shaped sample is reduced, the sample can be repeatedly ground and cleaned for use, the same sample can be tested at different points for multiple times, the same point can be repeatedly tested, and in-situ detection of the metal tellurium ingot can be performed. (2) Cleaning treatment: the processed high-purity metal tellurium ingot sample is immersed in a 15% nitric acid solution for acid washing, and the time is 15 min. After the acid washing is completed, the sample is washed with ultrapure water for three times, is placed in anhydrous ethanol for standby, and the obtained testing sample is taken out by using a polytetrafluoroethylene tweezers and is dried by using an argon gas hot air gun.

[0024] (3) Glow discharge mass spectrometry analysis: the sample obtained in step (2) is fixed with a sheet-shaped sample holder and placed in the sample chamber of a glow discharge mass spectrometer.

[0025] The glow discharge chamber is pre-cooled to -180℃, and the sample to be tested is pushed into the glow discharge chamber after being vacuumed by an ion pump. The discharge current is set to 1.5 mA, and the discharge voltage is set to 980 V. The test sample is pressurized and discharged.

[0026] After the sample is pre-sputtered for 15 min, the signal is collected, the resolution of the signal is 4000, and the signal intensity is 5.5x10 -10 A, and stable data is obtained after 7 tests.

[0027] Example 2: The method for testing the element content in a metal tellurium ingot based on glow discharge mass spectrometry in this embodiment includes the following steps: (1) Polishing treatment: 5.74 g of high-purity tellurium ingot with a purity of 6N is selected. After being washed with ultrapure water, it is processed into a sheet shape by high-mesh flexible white sandpaper. The test surface of the high-purity metal tellurium ingot is polished until the processed surface is smooth and the test area has a metallic luster.

[0028] (2) Cleaning treatment: The processed high-purity metal tellurium ingot sample is immersed in a 15% nitric acid solution for acid washing for 15 min. After acid washing, it is washed with ultrapure water for three times, and then placed in anhydrous ethanol for standby. The obtained sample to be tested is taken out by a polytetrafluoroethylene tweezers and dried by an argon hot air gun.

[0029] (3) Glow discharge mass spectrometry analysis: the sample obtained in step (2) is fixed with a sheet-shaped sample holder and placed in the sample chamber of a glow discharge mass spectrometer.

[0030] The glow discharge chamber is pre-cooled to -180℃, and the sample to be tested is pushed into the glow discharge chamber after being vacuumed by an ion pump. The discharge current is set to 1.5 mA, and the discharge voltage is set to 980 V. The test sample is pressurized and discharged.

[0031] After the sample is pre-sputtered for 15 min, the signal is collected, the resolution of the signal is 4000, and the signal intensity is 6.7x10 -10 A, and stable data is obtained after 7 tests.

[0032] Example 3: The method for testing the element content in a metal tellurium ingot based on glow discharge mass spectrometry in this embodiment includes the following steps: (1) Polishing treatment: 7.83 g of high-purity tellurium ingot with a purity of 5N was selected. After ultrasonic cleaning with ultrapure water, the high-purity tellurium ingot was polished into a sheet shape by using high-mesh flexible white sandpaper. The test surface of the high-purity tellurium ingot was polished until the processed surface was smooth and the test area had a metallic luster.

[0033] (2) Cleaning treatment: The processed high-purity tellurium ingot sample was immersed in a 20% nitric acid solution for acid washing for 10 min. After acid washing, the sample was washed with ultrapure water three times and then placed in anhydrous ethanol for standby. The obtained sample was taken out by using a polytetrafluoroethylene tweezer and dried by using an argon hot air gun.

[0034] (3) Glow discharge mass spectrometry analysis: The sample obtained in step (2) was fixed by using a sheet-shaped sample holder and placed in the sample chamber of the glow discharge mass spectrometer.

[0035] The glow discharge chamber was pre-cooled to -180°C. After the sample was vacuumized by an ion pump, it was pushed into the glow discharge chamber. The discharge current was set to 1.5 mA, the discharge voltage was set to 980 V, and the test sample was pressurized and discharged.

[0036] After the sample was pre-sputtered for 15 min, the signal was collected. The resolution of the signal was 4000, and the signal intensity was 6.5 x 10 -10 A. Stable data were obtained after 7 tests.

[0037] Comparative Example 1 The method for testing the element content in the metal tellurium ingot based on the glow discharge mass spectrometry of the present comparative example comprises the following steps: (1) 7.72 g of high-purity tellurium ingot with a purity of 7N was selected. After the sample was melted, it was filled into a special (3 x 23 mm) polytetrafluoroethylene mold, and then taken out after solidification. Ф

[0038] (2) The processed high-purity metal tellurium ingot sample was immersed in a 15% nitric acid solution for acid washing for 10 min. After acid washing, the sample was washed with ultrapure water three times and then placed in anhydrous ethanol for standby. The obtained sample was taken out by using a polytetrafluoroethylene tweezer and dried by using an argon hot air gun.

[0039] (3) The sample obtained in step (2) was fixed by using a needle-shaped sample holder and placed in the sample chamber of the glow discharge mass spectrometer.

[0040] The glow discharge chamber was pre-cooled to -180°C. After the sample was vacuumized by an ion pump, it was pushed into the glow discharge chamber. The discharge current was set to 1.5 mA, the discharge voltage was set to 980 V, and the test sample was pressurized and discharged.

[0041] ​After the sample was pre-sputtered for 15 min, the signal was collected, the resolution of the signal was 4000, and the signal intensity was 8.2 x 10 -10 A, stable data was obtained after 7 tests.

[0042] Comparative Example 2: The method for testing the element content in the metal tellurium ingot based on the glow discharge mass spectrometry of the present comparative example comprises the following steps: (1) A high-purity tellurium ingot with a purity of 6N7 was selected, and the total amount was 5.18 g. After being washed with ultrapure water by ultrasonic, the high-purity tellurium ingot was ground into a sheet shape. The test surface of the high-purity tellurium ingot was polished until the processed surface was smooth and the test area was shiny.

[0043] (2) The processed high-purity tellurium ingot sample was immersed in a 15% nitric acid solution for acid washing for 15 min. After acid washing, the sample was washed with ultrapure water for three times, and then was placed in anhydrous ethanol for standby. The obtained sample to be tested was taken out by a polytetrafluoroethylene tweezers, and was dried by an argon hot air gun.

[0044] (3) The sample to be tested obtained in step (2) was fixed by a sheet sample clamp, and was placed in the sample chamber of the glow discharge mass spectrometer.

[0045] The glow discharge chamber was pre-cooled to -180°C, and the sample to be tested was pushed into the glow discharge chamber after being vacuumized by an ion pump. The discharge current was set to 1.5 mA, the discharge voltage was set to 980 V, and the test sample was pressurized and discharged.

[0046] After the sample was pre-sputtered for 15 min, the signal was collected, the resolution of the signal was 4000, and the signal intensity was 8.2 x 10 -10 A, stable data was obtained after 7 tests.

[0047] Comparative Example 3: The method for testing the element content in the metal tellurium ingot based on the glow discharge mass spectrometry of the present comparative example comprises the following steps: (1) A high-purity tellurium ingot with a purity of 6N5 was selected, and the total amount was 4.55 g. The sample was ground by a quartz mortar until the sample was a powder with a particle size of greater than 200 mesh.

[0048] (2) The 7N indium sheet was boiled and cleaned with 40% nitric acid, and was placed in a teflon cup and washed with ultrapure water for three times. The cleaned indium sheet obtained in step (2) was taken out by a polytetrafluoroethylene tweezers, and was dried by an argon hot air gun.

[0049] (3) The sample to be tested obtained in step (1) was transferred to the cleaned indium sheet by a sulfuric acid paper special for sample preparation, and was covered with a sulfuric acid paper special for sample preparation. A slight pressure was applied to the sample to be tested, and the sample was pressed and prepared.

[0050] (4) The sample to be tested obtained in step (3) is fixed by a sheet sample clamp and placed in a sample chamber of the glow discharge mass spectrometer.

[0051] The glow discharge chamber is pre-cooled to -180°C, and the sample to be tested is pushed into the glow discharge chamber after being vacuumized by an ion pump. The discharge current is set to 1.5 mA, and the discharge voltage is set to 980 V to pressurize and discharge the test sample.

[0052] After the sample is pre-sputtered for 15 min, the signal is collected, the resolution of the signal is 4000, and the signal intensity is 5.1×10 -10 A, and stable data is obtained after 7 tests.

[0053] In the above embodiment 1, the photo of the untreated conventional high-purity metal tellurium ingot sample is shown in FIG. 1, and due to the semi-metallic property and layered hexagonal crystal structure of the metal tellurium, the surface of the tellurium block sampled after fragmentation has rib-like stripes and is uneven, and there is no flat surface for stable glow discharge testing. As shown in FIG. 2, it is the photo of the sheet sample of the high-purity metal tellurium ingot prepared after being treated by the method of embodiment 1 of the present application, and the originally uneven surface is smooth and has a metallic luster, which can be used for stable glow discharge testing. The photo of the sputtered surface of the high-purity metal tellurium ingot sheet sample after the completion of the glow discharge is shown in FIG. 3, and the black annular area is the glow discharge sputtering area, and it can be seen that the glow discharge is stable and normal. Figure 2 Figure 3 Figure 4

[0054] The glow discharge mass spectrometer calculates the mass fraction of each element to be tested in the high-purity metal tellurium ingot according to the semi-quantitative analysis principle of the glow discharge mass spectrometer and the relative sensitivity factor. The mass fraction of each element to be tested in the 7N metal tellurium ingot in the above embodiment 1 is shown in Table 1, the mass fraction of each element to be tested in the 6N metal tellurium ingot in embodiment 2 is shown in Table 2, the mass fraction of each element to be tested in the 6N7 metal tellurium ingot in comparative example 1 is shown in Table 3, the mass fraction of each element to be tested in the 6N5 metal tellurium ingot in comparative example 2 is shown in Table 4, and the mass fraction of each element to be tested in the 6N5 metal tellurium ingot in comparative example 3 is shown in Table 5.

[0055]

[0056]

[0057]

[0058]

[0059]

[0060] Figure 2 3 ​​​​​, 4 and Table 1, Table 2, Table 3, Table 4, Table 5 can be seen: The comparative example 1 prepares a high-purity metal tellurium ingot needle-shaped sample by melting and shaping, and other steps remain unchanged. The high-purity metal tellurium ingot sample needs to be remelted and a special mold is used in the process. The steps are relatively cumbersome and require equipment. The corresponding test results in Table 3 show that the contents of environmental elements such as Na, Al and Si are relatively high, which cannot be ruled out the factors introduced by sample preparation. The appearance of the high-purity metal tellurium ingot sample after melting is completely changed, and in-situ detection of different positions of the original tellurium ingot cannot be performed, and repeated testing of the same position of the tellurium ingot area cannot be performed.

[0061] The comparative example 2 uses ordinary sandpaper to prepare a high-purity metal tellurium ingot sheet-shaped sample, and other steps remain unchanged. The corresponding test results in Table 4 show that the contents of environmental elements such as Na, Mg, Al and Si are relatively high, which cannot be ruled out the factors introduced by sample preparation.

[0062] In the comparative example 3, the sample is ground into a high-purity metal tellurium powder for sample preparation, and other steps remain unchanged. The high-purity metal tellurium ingot sample needs to be ground and a sheet-shaped sample is prepared through a 7N indium sheet in the process. The steps are relatively cumbersome and require consumables. The corresponding test results in Table 3 show that the contents of environmental elements such as Na, Al and Si are relatively high, and the contents of impurity elements such as P, Fe and Re in In are relatively high, which cannot be ruled out the factors introduced by sample preparation. In element cannot be tested to obtain true data due to the sample preparation matrix. The structure of the high-purity metal tellurium ingot sample after being processed into a powder is completely changed, and in-situ detection of different positions of the original tellurium ingot cannot be performed, and repeated testing of the same position of the tellurium ingot area cannot be performed.

[0063] The present application grinds the high-purity metal tellurium ingot into a flat and smooth surface by white sandpaper, prepares a sheet-shaped sample to be tested, and utilizes the physical properties of tellurium. Because the toughness of tellurium is low, it is difficult to obtain a clean and smooth tellurium ingot sample by cutting, and usually the tellurium ingot is ground into a powder for testing. Through sandpaper grinding, a high-purity sample suitable for glow discharge mass spectrometry detection can be prepared, which has uniform texture and can be in-situ detected. The sample preparation operation is simple, and almost no impurity elements are introduced, which can effectively solve the problem that the high-purity metal tellurium ingot cannot be directly sampled.

[0064] The metal tellurium ingot sample of the present application is directly sampled as a sheet-shaped sample for glow discharge mass spectrometry, does not introduce impurities into the sample, the test signal body is the test sample, and the potential impurity element pollution in the sample preparation process is reduced.

[0065] The present application reduces the influence of the external environment on the surface of the block-shaped sample through acid pickling and pre-sputtering operations.

[0066] The block-shaped sample prepared by the present application can be repeatedly ground and washed for use, and the same sample can be tested at different points multiple times, or repeated testing at the same point can be performed, and in-situ detection of the high-purity metal tellurium ingot can be performed.

[0067] The application is directed to high-purity metal tellurium ingot, and a resolution of >4000 and a test signal of ≥3.0*10 -10 The method can meet the requirements of simultaneously detecting multiple trace impurities in the high-purity metal tellurium ingot, and meet the requirements of scientific research and production detection.

[0068] Although the present application has been disclosed with the preferred embodiments as above, it is not intended to limit the present application. Any person skilled in the art can make many possible changes and modifications to the technical solutions of the present application, or modify equivalent embodiments with equivalent changes, without departing from the scope of the technical solutions of the present application, by using the disclosed technical contents. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, without departing from the content of the technical solutions of the present application, shall fall within the protection scope of the technical solutions of the present application.

Claims

1. A method for determining the elemental content in metallic tellurium ingots based on glow discharge mass spectrometry, characterized in that: Includes the following steps: S1. The cleaned metal tellurium ingot to be tested is polished. The polishing process includes polishing the metal tellurium ingot to be tested into a sheet shape with white sandpaper, and the test surface is flat, smooth and has a metallic luster. S2. The sheet-like sample obtained by grinding is sequentially acid-washed, water-washed, and dried; S3. Perform glow discharge mass spectrometry analysis on the dried sheet sample to obtain the content of impurity elements.

2. The method for determining the elemental content in metallic tellurium ingots based on glow discharge mass spectrometry according to claim 1, characterized in that: In step S1, the white sandpaper is 1000-1200 mesh flexible white sandpaper.

3. The method for determining the elemental content in metallic tellurium ingots based on glow discharge mass spectrometry according to claim 1 or 2, characterized in that: In step S2, the pickling is performed using nitric acid.

4. The method for determining the elemental content in metallic tellurium ingots based on glow discharge mass spectrometry according to claim 3, characterized in that: In step S2, the volume fraction of nitric acid during pickling is 15-20%, and the pickling time is 10-15 min.

5. The method for determining the elemental content in metallic tellurium ingots based on glow discharge mass spectrometry according to claim 1 or 2, characterized in that: In step S2, the water washing is performed multiple times.

6. The method for determining the elemental content in metallic tellurium ingots based on glow discharge mass spectrometry according to claim 1 or 2, characterized in that: In step S3, the glow discharge mass spectrometry analysis includes cooling, vacuuming, and sputtering in sequence. The cooling temperature is -160 to -180 °C, the discharge current during sputtering is 1.2 to 1.5 mA, the discharge voltage is 900 to 1000 V, and the pre-sputtering time is 15 to 20 min.

7. The method for determining the elemental content in metallic tellurium ingots based on glow discharge mass spectrometry according to claim 1 or 2, characterized in that: In step S1, the purity of the metal tellurium ingot to be tested is ≥5N.

8. The method for determining the elemental content in metallic tellurium ingots based on glow discharge mass spectrometry according to claim 1 or 2, characterized in that: In step S3, glow discharge mass spectrometry analysis includes in-situ testing of the sheet sample or multiple tests at the same test site of the sheet sample.

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