JPS6078335A - Analyzing method of niobium in barium titanate - Google Patents

Abstract

PURPOSE:To enable quick and exact analysis in quantitative determination of Nb in barium titanate by dissolving a sample BaTiO3 into hydrochloric acid, adding tartaric acid and H3BO3 thereto, subjecting the soln. prepd. in such a way to plasma emission spectrochemical analysis and measuring the emission intensity of a specific wavelength. CONSTITUTION:Nb is thoroughly eluted in analysis of Nb in a BaTiO3 element or the like by operating four times the operation of grinding the sample with an agate mortar, putting a specified amt. of the ground sample together with concd. hydrochloric acid into a pressurized ''Teflon'' crucible and stirring the mixture for 30min after heating the same for 1hr at 145 deg.C. The mixture is cooled after elution and is then diluted and filtered. The filtrate is added to an aq. H3BO3 soln. and the soln. is further filtered. The filter paper is washed with an aq. tartaric acid soln. and is further washed. The entire washing liquid is added to the filtrate to make specified volume. The soln. is subjected to plasma emission spectrochemical analysis and the emission intensity of 2,697Angstrom wave is measured. The Nb in the sample is accurately and quantitatively determined from said value by using a calibration curve obtd. by adding preliminarily a known amt. of Nb to the sample and measuring similarly the Nb.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for quantitatively analyzing niobium in barium titanate by plasma emission spectrometry.

Qualitative and quantitative determination of impurities and additives in BaTiO3 elements is necessary for manufacturing process control and product quality control. To this end, it is necessary to establish highly accurate and accurate analysis methods. Conventionally, it has been used for quantitative analysis of elements in ceramics, not just BrzT I Os semiconductors.

Mainly, the absorption 4 degree method shown in the conceptual diagram of FIG. 1 has been used. However, in this method, the pretreatment of the sample before measurement was very complicated and took a lot of time.

In comparison, the plasma emission method has the advantage of being able to directly quantify the sample as long as it is dissolved, being simple and short, and being less prone to errors. Also, unlike conventional methods, anyone can carry out the measurement without having to be skilled.

This method uses plasma emission spectrometry, and B a T 1
This paper attempts to provide a method for quantitatively analyzing niobium in 03 elements.

The present invention comprises barium titanate, HCl, tartaric acid and H2
Prepare a standard solution by adding a predetermined amount of Nb to a solution containing BO3, apply this standard solution to a plasma emission analyzer, measure the total emission intensity at a wavelength of 2697^, and calculate the value. A calibration curve is created from the above amount of NbO, barium titanate containing an unknown amount of Nb is dissolved in HCt,
Tartaric acid and H3BO3 are added to this solution, and this solution is attached to a plasma emission analyzer to measure the luminescence intensity at a wavelength of 2697k to determine the value.This value is correlated to the above calibration curve to estimate the Nb content. The gist of this paper is a method for analyzing niobium in barium titanate.

Hereinafter, the present invention will be explained in detail with reference to Examples.

6.1 Reagents used■Niobium standard solution・・・・・・・・・10 for atomic absorption
001000pp solution) ■Hydrochloric acid (HCl)...For measuring toxic metals ■Boric acid (H3BO3)...Supermoor manufactured by Merck ■Hydrofluoric acid (HF)・・・・・・Reagent grade ■Barium titanate (BaTi03)・・・Commercial raw material for ceramics ■Copper standard solution・・・・・・・・・・・・・・・1 [
)00 ppm (HCt solution) 6.2 Analyzer (1) High frequency argon plasma emission spectrometer...
・・Manufactured by Japan Jarrell Ash Co., Ltd. ICAψ-500 (
2) Operating conditions/High frequency power... Old... Item...1
．． 4KW/Photomaru applied voltage・・・・・・・・・・・・
445KV spear sample gas flow rate...
・0.4251/m1n-cooler gas flow rate...
......14 t/imin・Plasma gas flow rate......1t/m1n6 filtration Experimental results and considerations 6.31 Sample dissolution method B a T i O3 element After crushing with an agate milk drum, 0
．． The mixture was placed in a 5 g't Teflon pressurized crucible, a stirrer was placed there, 20 yn/z of concentrated hydrochloric acid was added thereto, and the crucible was sealed. That's 14 in total
Heat and dissolve at 5°C for 6 hours. At this time, in order to sufficiently dissolve the sample, the sample was heated for 1 hour and then stirred for 30 minutes over starch, and the cycle of heating and stirring was repeated 4 times for a total of 6 hours.

After dissolving the sample, B remains in the sample solution. Ct2 and Si02
However, there is no problem because B a CL2 dissolves when the liquid is diluted with water. Also, Si 02.

It can be removed by filtering the stock solution through filter paper.

Further, after drying the filter paper, the filter paper was examined by fluorescent X-ray analysis, but no niobium was detected. On the other hand, after dissolving the metal in the paper in HF, masking the F with boric acid and I
Although it was measured by CP (plasma emission spectrometry), niobium was not detected. Therefore, BaT in the form of Nb2O5
It was confirmed that all of the niobium added to the iO2 raw material was dissolved in hydrochloric acid and contained in the filtrate after being fired as an element.

3, 3.2 Preventing the hydrolysis of niobium Niobium is a metal that is very easily hydrolyzed, so if you leave the sample solution and standard solution for the calibration curve without taking any measures,
If you leave it for a while, it will quickly form a precipitate. therefore)
Masking of niobium with IF or tartaric acid was investigated.

Ro, Ro, 2,1 f (in concHct solution immediately after dissolving the niobium mask sample with F (hydric acid) [HFf.

When added, BaTiF6 precipitates. However, this time, if we diluted the sample stock solution (cone HCL 2Drnl) by adding about 50ml of IC water and then added HF, BaT
It was found that no precipitation of i03 occurred.

By adding HF, niobium can be masked, but HF attacks glass products, so if this device uses glass products, it will not be able to mask the niobium. It cannot be determined. Therefore, it is necessary to add 2 g of boric acid to 1 ml of cone HF to mask the excess F-. As described above, since the operation itself is complicated with HF, we investigated using tartaric acid as a mask for niobium itself.

3.3.2.2 Mask of niobium with M tartaric acid Sample solutions containing niobium with and without tartaric acid were prepared immediately after dissolution, left for several days, filtered L7, and filter paper was analyzed using fluorescent X-rays. However, niobium was not detected in the sample containing tartaric acid, but niobium precipitation was clearly observed in the sample without tartaric acid.

``From this, it was confirmed that niobium can be masked with tartaric acid, so it was decided to mask niobium by adding the same amount of tartaric acid to both when preparing the actual sample solution and the calibration curve solution.

6.6゜3 Determining the analytical line Among the emission lines of niobium, excluding those that overlap the OH band of water, use the wavelength of 2<597A, which has the strongest emission intensity.

3, 3.4 Linearity of the calibration curve The concentration of niobium is 0.0.5.1.2.3. The niobium standard solution was diluted so as to have a constant value of 100 mt. Since the niobium standard solution is an HF solution, H3BO is used to mask the excess F-.

Hs BOs 0.03 g/100
It was set as rnL.

Further, cone HCt20st/10D mt was used.

As a result, as shown in FIG. 2, very good linearity was exhibited. Here I (i-ICP origin strong evacuation.

C is the niobium concentration, and SC is the standard deviation of the concentration.

If R is a linear correlation coefficient, then 3, 3.5 Effect of decomposition reagent Changes in the acid concentration in the solution affect the emission intensity of ICP, so the acid concentration of both the actual sample solution and the standard solution for the calibration curve (HCl, H2BO3, I(F.

tartaric acid).

3, 3.6 Effect of coexisting elements The niobium concentration was kept constant at 2 ppm, TI, BcL.

The influence of BaTiO3, Cu, and Dy on the measured value of niobium was investigated by changing their concentrations. The calibration curve is 3.4. Using the samples prepared in , i, the acid concentration of each sample was adjusted to that of the calibration curve sample.

3.3.6. Influence of I Ti Table 1 and FIG. 6 show the results of examining the influence of varying the Ti concentration t from 200 to 11,000 pp.

Although the recovery rate of niobium tends to increase as the Ti concentration increases, no significant difference is observed.

Table 1 and Figure 4 show the results of examining the effects of changing the concentration of IBa up to 3000 ppm. Although the recovery rate of niobium tends to decrease as the iBα concentration increases, no significant difference is observed.

Ro, Ro, 6. '5 Influence of Cu Table 3 and FIG. 5 show the results of examining the influence of varying the Cu concentration up to 201) JOOppm.

It can be said that there is no influence of Cu.

6 Table 3, 3.6.4 Influence of Dy Table 4 and FIG. 6 show the results of examining the influence of varying the concentration of Dy from 1 to 50 ppm.

When the Dy concentration is high (the recovery rate also tends to become daytime), no significant difference is observed.

Table 4 3.3.6.5 Influence of BaTiOs B, T i 03 raw material without the addition of niobium is melted in a pressurized crucible, and the amount is 0.1 to 0-5 g/
The effects of niobium on the measured values were investigated by varying the amount of niobium added up to 100 mt, and the results are shown in Table 5 and FIG.

B. It can be said that the effect of adding TiO3 is almost negligible.

Table 5 Ti and BeL' (i7 When added alone, it affects the recovery rate of niobium, but when added in the form of BaTiOs, the recovery rate is within ±2%, so analysis of actual samples However, since both are major coexisting elements, BaTiOs k 0.0.
Add 5 g/l'ODmA.

Since neither Cu nor Dy has any influence within the Nosaka range of the actual sample, they are not particularly considered.

3, 3.7 Analysis of simulated sample A simulated sample with a niobium concentration of 2 ppm as shown in Table 6 was prepared, and BcTiOak 0.5 g/100
The recovery rate of niobium was measured using a calibration curve with mA addition. Note that 100 rinses were kept constant for the pseudo sample and the sample for the calibration curve.

Table 6 con　HCt20ml1100mt HsBOs 0.03g/100g Tartaric acid 3g/100t The acid concentration was adjusted to

As a result, a satisfactory recovery rate of niobium was obtained as described above.

3, 3.8 Analysis of Actual Sample After filtering the sample solution dissolved in a pressurized crucible, 3 g of tartaric acid and 0.03 g of H3BO3 were added to maintain a constant 1'OD. This was measured by ICP using the calibration curve sample used in the above pseudo sample measurement, and the following results were obtained.

Here, n is the number of samples, and 7 is the average weight content of niobium (
wt% Nb g/BcLTi03 g )t S ke standard deviation, C, V, are coefficients of variation.

n = 4; = 0.0663 wt%Nb S = 5.62 (See figure)■
After crushing BαTi0se agate with a milk drum, 0.5 g is weighed out.

■ Place the entire sample into the pressurized crucible, concHct2Qy
After adding the at and stirring bar, seal the container.

■ Heat the crucible at 145℃ for 1 hour, and then
The operation of stirring for 0 minutes is repeated 4 cycles, and the sample is dissolved by heating and stirring for a total of 6 hours.

(2) After the crucible has cooled down, dilute the sample solution by adding 2 mmt of fishing rod, and then filter it using a funnel and 5c filter paper. The filtrate is taken into a 100 m/- volumetric flask. In a volumetric flask, add 0.03 g of H3BO and 15 yat'i of water to dissolve it.

■ After filtration, 20ml of an aqueous solution containing 3gt of tartaric acid dissolved in it.
Wash the filter paper with water and then rinse with water.

Transfer the washing solution to the same flask.

(7) After adding water to a lasco and making it constant for 100 rinsings, measure at a wavelength of 2697λ.

3, 4.2 Preparation and measurement of standard sample for calibration curve (see Figure 9) ■ 1000 for niobium atomic absorption. ppm standard solution (
2% HF dissolved in water for 5 hours (pickled)
Dissolve the HsBOst in advance with 0.5 g of water and place in a 100-liter volumetric flask.

■ After adding water to make it constant at 100 t, transfer the liquid to a polyethylene sample bottle, and add 50 t of water.
Use mniobium standard solution.

■ BaTlOs without niobium in a pressurized crucible
Dissolve in 0.5 g f cone HCt2QmL. At this time, the dissolution method is based on the dissolution method of the actual sample.

(2) After filtering the B a Ti 03 stock solution, the filter paper is washed with an aqueous solution containing 3 g of tartaric acid, and then with water.

■ The filtrate and washing liquid were taken into a 100 mA volumetric flask in which I(,BO3 had been dissolved) and frA&, 50 mA.
From the ppm standard solution with a whole pipette, 0.1. 2.
4. After taking 6 tnL of each and adding it to the volumetric flask,
00 rinse t constant, respectively 0, 0.5.1, 2.3
ppm niobium calibration solution.

■ The niobium 50 ppm standard solution already contains
Since 0.005g/poison of BO1 is included, niobium for the calibration curve is 0.0.5.1, 2. ．． 3ppm solution IC H
3B Os t=each 0.05.0.0.25゜0
．． 02.0.01.0+g H8BO in final solution
.

and create a calibration curve.

Using the calibration curve created in 4.2, 3.4.1 (
2:) Determine the niobium content from the luminescence intensity of the actual sample.

The reason why tartaric acid was added to both the actual sample solution and the standard solution for the calibration curve was to mask the niobium and prevent the hydrolysis of the niobium.

The reason why the concentrations of hydrochloric acid, boric acid, and tartaric acid contained in both the actual sample solution and the standard solution for the calibration curve were made to be the same was to completely eliminate the influence of the difference in concentration. The standard solution for the calibration curve contains BaTlOs, which is the main coexisting element in the actual sample solution.
The purpose of adding 5H3B03 after melting is to eliminate its influence. The purpose of adding 5H3B03 is to mask F-IF and eliminate the glass-corrosive property of T-IF.

As explained above, the present invention uses Icp*- and performs direct quantification using the calibration curve method, so accurate values can be obtained in a short time. Therefore, niobium in the BαT103 semiconductor can be quantitatively analyzed quickly, accurately, and with high precision, making it possible to control product quality, process control, and establish manufacturing conditions. It has the effect of clarifying the differences in properties caused by subtle differences in niobium content.

[Brief explanation of drawings]

Figure 1 is a conceptual diagram showing the procedure for conventional quantitative analysis of elements in BaTlOs, Figure 2 is a graph showing the entire calibration curve for niobium,
Figures 6 and 7 show the influence of coexisting elements on the recovery rate of Nb.
FIG. 3 is a graph showing Ti. Figure 4 is B - Figure 5 is Cu, Figure 6 is Dy, Figure 7 is B
FIG. 8 is a conceptual diagram showing the procedure for dissolving a sample and measuring, and FIG. 9 is a conceptual diagram showing the procedure for preparing a standard solution for creating a calibration curve and measuring. Agent Patent Attorney San Kimura

Claims (1)

[Claims] A standard solution was prepared by adding a predetermined amount of Nb (i-) to a solution containing barium titanate, HCl, tartaric acid, and H3BO3. This standard solution was subjected to a plasma emission analyzer to measure the emission intensity at a wavelength of 2697X. Measure and record the value, create a calibration curve from that value and the amount of NbO, and calculate the unknown amount of Nb
i Dissolve the barium titanate contained in HCl, add tartaric acid and H3BO3 to this, apply this solution to a plasma emission analyzer, measure the luminescence intensity at a wavelength of 2697, calculate the value, and calculate the value. A method for analyzing niobium in barium titanate, characterized in that the content of Nb is determined in accordance with the calibration curve.