JP2000097885A - Fluorescence x-ray analyzing method, and fluorescence x-ray analyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow an accurate overlap correction using an overlap correcting coefficient independent from analyzer sensitivity and a sample composition in an FP(fundamental parameter) method or the like. SOLUTION: In an FP method, measured intensity relating to each component in a sample is converted at first into a theoretical intensity scale to provide converted intensity, using as a disturbance ray a fluorescent X-ray having a spectrum of which at least one portion is overlapped with a spectrum of a measured X-ray. The converted intensity is corrected to provide intensity based on the measured intensity using theoretical intensity of the disturbance ray calculated while assuming at least one of a thickness and a containing rate of each component in the sample, to be compared with the theoretical intensity in each component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to fluorescence X from a sample.
The present invention relates to a fluorescent X-ray analysis method and apparatus for obtaining the content of each component in a sample and the like using theoretical intensity calculated for fluorescent X-rays based on the measured intensity of the X-ray.

[0002]

2. Description of the Related Art Conventionally, one of the so-called fundamental parameter methods (hereinafter, referred to as the "parameter method") is one of the fluorescent X-ray analysis methods for obtaining the content of each component (element) in a sample based on the measured intensity of the fluorescent X-ray from the sample. FP method). For example, when the content of each component is determined by the FP method, the fluorescent X of each component generated by irradiating the sample with primary X-rays is used.
Using the intensity based on the measured intensity of the line and the theoretical intensity of the fluorescent X-ray of each component calculated assuming the content of each component in the sample, the content of each of the assumed components is adjusted so that both intensities coincide. The ratio is corrected by successive approximation to calculate the content of each component.

Now, the fluorescence X generated from each component in the sample
The line itself does not spread in wavelength (or energy), but due to the resolution of the analyzer, the measured fluorescent X-ray has some spread in wavelength (or energy). Such a fluorescent X-ray measurement result (relation between intensity and wavelength or energy) is called a spectrum. Here, for example, there is a case where the Ni-Kβ1 line overlaps with a part of the spectrum as an interference line with the fluorescent X-ray Cu-Kα line to be measured. Conventionally, in order to remove the influence of such an interference line, Japanese Patent Laid-Open No.
As shown in No. 123071, overlap correction was performed using the following equation (1).

[0004] _{^{C I i = I i -Σ 1}} γ ik T I k ... (1)

[0005] Here, ^C I _i, using the theoretical strength ^T I _k and the overlap correction coefficient ¹ gamma _ik interference line according to component k,
Is a correction intensity overlap was corrected measured intensity I _i of the component i. Then, for example, using the following equation (2), and converting the overlapping correction intensity ^C I _i to the theoretical intensity scale, as intensity based the converted intensity ^CS I _i the measured intensity, compared with the theoretical strength ^T I _i I was The subscript ^C of the left shoulder of I
Indicates that the intensity is the overlap-corrected intensity, ^T indicates the theoretical intensity, ^S indicates the intensity converted to the theoretical intensity scale, and ^CS indicates the intensity converted to the theoretical intensity scale after the overlap correction. Indicates that there is. Also, different numbers are added as subscripts to the left shoulder of the overlap correction coefficient γ to distinguish different types of overlap correction coefficients.

^CS I _i = a _i ^C _{i i} ² + b _i ^C _{i i} + c _i (2)

However, in such a method, equation (1)
In the theoretical intensity scale, the theoretical intensity ^{T of the} disturbance line
Since I _k is multiplied by an overlap correction coefficient ¹ γ _ik to correct the measurement intensity I _i , which is a measurement intensity scale, the overlap correction coefficient
Will depend on the sensitivity of ¹ gamma _ik is used apparatus can not accurately overlap correction unless seek correction coefficient ¹ gamma _ik overlap each device.

Further, conventionally, there is a so-called semi-fundamental parameter method (hereinafter referred to as an SFP method) as another method for obtaining the content of each component in a sample based on the measured intensity of fluorescent X-rays from the sample. In this SFP method, the theoretical intensity of fluorescent X-rays to be generated from a plurality of samples whose composition is assumed is calculated, and a theoretical matrix correction constant for absorption and excitation of fluorescent X-rays is calculated based on the theoretical intensity. The calibration curve corrected using the matrix correction constant is applied to the measured intensity of the fluorescent X-ray generated from each component in the sample to determine the content of each component. That is, although the SFP method belongs to the calibration curve method, the matrix correction constant is experimentally obtained by using the standard sample corresponding to the sample to be analyzed in the normal calibration curve method, and the fluorescent X-ray is obtained using the FP method. This is a method of calculating the theoretical strength and eventually calculating the theoretical matrix correction constant. This SFP
In the method, when the influence of the interference line is removed, the overlap correction has been conventionally performed using a calibration curve represented by the following equation (3).

[0009] _{W i = (a i I i} 2 + b i I i + c i) (1 + Σα ij W j) -Σ 2 γ ik W k ... (3)

[0010] That is, by applying the calibration curve overlap corrected by using the first-order equation ² gamma _ik W _k relating to content W _k of each component k to generate interference lines, content W _i of each component i in the sample I was seeking. Here, I _i is the intensity measured as each fluorescent X-ray, a _i , b _i , and c _i are calibration curve constants, Σα _ij
W _j is the so-called matrix correction term, alpha _ij theory matrix correction constant, ² gamma _ik overlap correction coefficient for coexisting elements. Was a ² gamma _ik W _k correction terms overlap, according to the preamble of the influence of the overlapping of the fluorescent X-ray to be measured of the disturbing lines by interfering components k is proportional to the content of W _k interfering components k. However, as will be described later, this assumption is not strictly correct, and the overlap correction coefficient ² γ
_{Since ik} does not become a constant depending on the composition of the sample, accurate overlap correction cannot be performed unless it is obtained for each sample type.

Further, as disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 10-123071, it is conceivable to correct the overlap by using the calibration curve represented by the following equation (4) and the previous equation (1) in the SFP method. .

W _i = (a _i ^C _i ² + b _i ^C _{i i} + c _i ) (1 + Σα _ij W _j ) (4)

^C I _i = I _i −Σ ¹ γ _ik ^T I _k (1)

However, in this case, since equation (1) is used, the overlap correction coefficient ¹ γ _ik depends on the sensitivity of the device used, as in the above-described overlap correction of the conventional FP method. It fails to accurately overlap correction unless seek correction coefficient ¹ gamma _ik overlap.

[0015]

That is, the conventional FP
In the overlap correction in the method and the SFP method, since the overlap correction coefficient depends on the sensitivity of the apparatus and the composition of the sample, accurate overlap correction cannot be performed unless the overlap correction coefficient is obtained for each apparatus or each type of sample.

The present invention has been made in view of the above-mentioned conventional problems, and based on the measured intensity of fluorescent X-rays from a sample, utilizing the theoretical intensity calculated for the fluorescent X-rays, the content of each component in the sample. In an X-ray fluorescence analysis method and apparatus for determining a ratio, etc., an X-ray fluorescence which can be accurately overlap-corrected by using an overlap correction coefficient independent of apparatus sensitivity and sample composition.
An object of the present invention is to provide a line analysis method and apparatus.

[0017]

In order to achieve the above-mentioned object, according to the X-ray fluorescence analysis method of the first aspect, in the so-called FP method, the spectrum which at least partially overlaps with the spectrum of the X-ray fluorescence to be measured. Is used as an interference line, and the measured intensity of each component in the sample is first converted to a theoretical intensity scale to obtain a converted intensity. Then, using the theoretical intensity of the disturbing line calculated assuming at least one of the thickness and the content of each component in the sample, the converted intensity is corrected to an intensity based on the measured intensity, and a theoretical value is obtained for each component. Compare with strength.

According to the method of the first aspect, in the FP method, the converted intensity obtained by converting the measured intensity to the theoretical intensity scale is corrected by the theoretical intensity of the disturbing line, which is the theoretical intensity scale. Accurate overlap correction can be performed using the correction coefficient.

In the X-ray fluorescence analysis method according to the second aspect, in correcting the converted intensity, the theoretical intensity of the interference line or the interference intensity calculated based on at least one of the thickness and the content of each component is assumed. The method differs from the method according to claim 1 in that the theoretical intensity of fluorescent X-rays having similar wavelengths in the same series is used.

According to the method of claim 2, the converted intensity is corrected by using the theoretical intensity of the disturbing line or the theoretical intensity of the fluorescent X-ray having the same system as the disturbing line and having a wavelength close to the disturbing line. In the case where a constant for calculating is not prepared, an accurate overlap correction can be performed using an overlap correction coefficient independent of the apparatus sensitivity.

According to the X-ray fluorescence analysis method of the present invention, in the so-called SFP method, a calibration curve is obtained by using X-ray fluorescence having a spectrum at least partially overlapping the spectrum of the X-ray fluorescence to be measured as an interference line. In this case, the influence of the interference line on the fluorescent X-rays to be measured is corrected using a theoretical matrix correction constant.

According to the method of the third aspect, in the SFP method, when obtaining a calibration curve, the influence of the interference line on the fluorescent X-ray to be measured is corrected strictly using the theoretical matrix correction constant. Accurate overlap correction can be performed using an overlap correction coefficient that does not depend on sensitivity or sample composition.

According to a fourth aspect of the present invention, there is provided an X-ray fluorescence analyzer.
First, a sample is irradiated with primary X-rays from an X-ray source, the intensity of fluorescent X-rays generated from each component in the sample is measured by a detection means, and the measured intensities are measured. There is a measuring means for storing. Further, the intensity based on the measured intensity stored in the measuring means and the theoretical intensity of the fluorescent X-ray of each component calculated by assuming at least one of the thickness in the sample and the content of each component are used. Calculating means for sequentially and approximately correcting and calculating the assumed thickness or the content of each component so as to match, and calculating at least one of the thickness or the content of each component.

Here, the calculating means uses the fluorescent X-ray having a spectrum at least partially overlapping with the spectrum of the fluorescent X-ray to be measured as an interference line, and uses the measured intensity stored in the measuring means as the theoretical intensity. Converted to a scale and converted intensity, using the theoretical intensity of the disturbing line calculated assuming at least one of the thickness or the content of each component, the intensity based on the measured intensity by correcting the converted intensity And According to the device of the fourth aspect, the same operation and effect as those of the method of the first aspect can be obtained.

According to a fifth aspect of the present invention, there is provided an X-ray fluorescence analyzer.
Wherein the correction means corrects the converted intensity in the calculation means, and calculates the theoretical intensity of the disturbing line or the same as the disturbing line calculated assuming at least one of the thickness and the content of each component. It differs from the device according to claim 4 in that the theoretical intensity of fluorescent X-rays whose wavelengths are close in series is used. According to the device of the fifth aspect, the same operation and effect as the method of the second aspect can be obtained.

[0026] The X-ray fluorescence spectrometer according to the sixth aspect is the third aspect.
An apparatus used in the method of (1), which first stores a theoretical matrix correction constant for absorption and excitation of fluorescent X-rays calculated based on the theoretical intensity of fluorescent X-rays to be generated from a plurality of samples whose composition is assumed. Correction constant storage means for performing the correction. Further, as a correlation between the measured intensity of the fluorescent X-rays generated and measured from each component in a plurality of different standard samples having a known composition, the content of the component in the standard sample, for each component, There is provided a calibration curve storage means for storing a calibration curve previously obtained by correction using a theoretical matrix correction constant.

Further, a measuring means for irradiating a sample with primary X-rays from the X-ray source, causing the detecting means to measure the intensity of fluorescent X-rays generated from each component in the sample, and storing the measured intensities. Have. Still further, there is provided a calibration curve applying means for applying the calibration curve to the measured intensity stored in the measuring means to determine the content of each component in the sample. Here, the calibration curve stored in the calibration curve storage means is a fluorescence X-ray having a spectrum that at least partially overlaps the spectrum of the fluorescent X-ray to be measured, and the fluorescence X-ray to be measured. Is corrected using the theoretical matrix correction constant. According to the device of the sixth aspect, the same operation and effect as the method of the third aspect can be obtained.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method according to a first embodiment of the present invention will be described. First, an apparatus used in this method will be described with reference to FIG. This device, first,
A sample stage 8 on which the sample 13 is fixed, an X-ray source 1 for irradiating the sample 13 with primary X-rays 2, and a fluorescent X-ray generated from the sample 13
Detecting means 10 for measuring the intensity of the line 6. The detecting means 10 includes a spectroscope 5 for separating the secondary X-rays 4 generated from the sample 13 and a detector 7 for measuring the intensity of each fluorescent X-ray 6 separated by the spectrometer 5. Further, the apparatus includes a control unit 17 including the following measurement unit 12 and calculation unit 16.

The measuring means 12 applies the X-ray source 1 to the sample 13.
Irradiates the primary X-rays 2 from the sample, causes the detecting means 10 to measure the intensity of the fluorescent X-rays 6 generated from each component in the sample 13, and stores the measured intensities. The calculating means 16 calculates the intensity based on the measured intensity stored in the measuring means 12 and the sample 13
And the theoretical intensity of the fluorescent X-ray of each component calculated assuming at least one of the thickness or the content of each component, and the assumed thickness or the content of each component so that both intensities match. Is corrected by successive approximation to calculate at least one of the thickness and the content of each component. Here, the calculating unit 16 sets the fluorescent X-ray having a spectrum at least partially overlapping with the spectrum of the fluorescent X-ray to be measured as an obstruction line, and converts the measured intensity stored in the measuring unit 12 into a theoretical intensity scale. Then, the converted intensity is corrected and the converted intensity is corrected using the theoretical intensity of the disturbing line calculated assuming at least one of the thickness and the content of each component to obtain an intensity based on the measured intensity.

The method of the first embodiment using this apparatus is as follows.
Are those belonging to the FP method, the sample 13 is a so-called thin film sample, that is, when a thin film formed by vapor deposition or the like on the substrate, similarly to determine the content of W _i, X-ray fluorescence of the components 6 using the intensity based on the measured intensity I _i and the theoretical intensity ^T I _i of the fluorescent X-ray of each component calculated assuming the thickness T in the sample 13 so that the two intensities match. The corrected thickness T is successively and approximately corrected to obtain a sample 13
Can be calculated.

Further, in Sample 13 which is a thin film sample,
The thickness T and the content W of each component_iWhere both are unknown
In this case, the X-ray fluorescence of each component
Argument ^TI_iAnd the measured intensity I of the fluorescent X-ray 6 of each component_iTo
Using the strength based on, so that the two strengths match,
Assumed thickness T and content W of each component_iIs successively approximated
The thickness T of the sample 13 and each component
Content W of_iCan be calculated. In addition, what is called a thin film
For bulk samples, the thickness is infinitely x-ray
And the content W of each component_iOnly required.

[0032] In the method of the first embodiment, in this FP method, the measured intensity performs overlap correction I _i, but as in the prior art, measuring the intensity I _i of the overlap correction to the ^(C I _i) Theory Instead of converting to the intensity scale ( ^CS I _i ), the measured intensity I _i is converted to the theoretical intensity scale ( ^S I _i ) and the overlap correction is performed ( ^SC I _i ).

The case where both the thickness T and the content W _i of each component are obtained in the sample 13 which is a thin film sample will be described below as an example. First, the measurement means 12 irradiates the sample 13 with the primary X-ray 2 to measure and store the intensity I _i of the fluorescent X-ray 6 generated from each component i in the sample 13. next,
The calculating means 16 first converts the measured intensity I _i of each component i in the sample 13 stored in the measuring means 12 into a theoretical intensity scale using the following equation (5), and obtains the converted intensity ^S _Ii . I do.

^S I _i = a _i I _i ² + b _i I _i + c _i (5)

The coefficients a _i, b _i, c _i for the translation, for example, since it is determined from the measured intensities I _i and theoretical strength ^T I _i for the standard sample 3 is a pure substance component i, calculated in advance means 16 To be stored. Note that the coefficients a _i and c _i need not always be used. Now, the calculating means 16 has an initial thickness T ⁽⁰⁾ assumed in advance.
And the content W _i ^{(0) of} each component are read,
Calculates a correction calculation from them successively and approximately until the thickness T and the content W _{i of} each component converge to a predetermined range.

To explain the n-th calculation, first,
The thickness T ⁽ⁿ⁾ assumed for the n-th time and the content W _i ^{(n) of} each component
Is substituted into a well-known theoretical intensity calculation formula to calculate an n-th theoretical X-ray fluorescence intensity ^T I _i ⁽ⁿ⁾ of each component. here,
A fluorescent X-ray having a spectrum at least partially overlapping the fluorescent X-ray to be measured is treated as an interference line, and the theoretical intensity ^T I _k ⁽ⁿ⁾ of the n-th interference line is calculated in the same manner. Next, the converted intensity ^S _Ii is corrected using the theoretical intensity ^T I _k ⁽ⁿ⁾ of the disturbing line. Specifically, the following equation (6):
By substituting the converted intensity ^S _Ii and the theoretical intensity ^T I _k ⁽ⁿ⁾ of the disturbance line, an n-th converted overlap correction intensity ^SCI _i ⁽ⁿ⁾ is obtained.

^SC I _i = ^S I _i −Σ ³ γ _ik ^T I _k (6)

[0038] Thus, according to the method of the first embodiment, the FP method, the measured intensity I of the converted intensity ^S I _i in terms of the theoretical intensity scale _i, theoretical strength of the disturbing line is a theoretical intensity scale ^T is corrected by I _k, the overlap correction factor ³ gamma _ik becomes constant that does not depend on device sensitivity can accurately overlap correction without determining the correction coefficient overlap each device.

Then, the n-th conversion overlap correction conversion intensity
^{The SC} I _i ⁽ⁿ⁾ is compared with the theoretical strength ^T I _i ⁽ⁿ⁾ as an intensity based on the measured intensity I _i , and the thickness T ^{(n + 1) of the (n + 1) th time} and the content W _i ^{(n +} Ask for ¹⁾ . Specifically, ΔT and ΔW _i are obtained from the following equations (7) and (8), respectively, and substituted into the following equations (9) and (10).

^SC I _i ⁽ⁿ⁾ = ^T I _i ⁽ⁿ⁾ + ΔT × (d ^T I _i ⁽ⁿ⁾ / dT) (7)

^SC I _i ⁽ⁿ⁾ = ^T I _i ⁽ⁿ⁾ + ΔW _i × (d ^T I _i ⁽ⁿ⁾ / dW _i ) (8)

T ^{(n + 1)} = T ⁽ⁿ⁾ + ΔT (9)

W _i ^{(n + 1)} = W _i ⁽ⁿ⁾ + ΔW _i (10)

It should be noted that (d ^T I _i ⁽ⁿ⁾ / dT) in equation (7)
Is the theoretical intensity ^T I _i when the thickness is changed by dT.
^The amount of change of ⁽ⁿ⁾ is ^expressed by (d ^T I _i ⁽ⁿ⁾ / dW in equation (8)).
_i T) is the amount of change in the theoretical intensity ^T I _i ⁽ⁿ⁾ when the content W _i of each component is changed by dW _i .

When the following equations (11) and (12) are satisfied, the thickness T ^{(n + 1)} and the content W _i ^{(n + 1) of} each component are obtained.
Are converged, and if they are not satisfied,
The calculation after the calculation of the theoretical intensity ^T I _i ^{(n + 1)} is repeated. Note that β _T and β _W in Expressions (11) and (12) are predetermined convergence determination values.

| T ^{(n + 1)} / T ⁽ⁿ⁾ −1.0 | <β _T (11)

| W _i ^{(n + 1)} / W _i ⁽ⁿ⁾ −1.0 | <β _W (12)

It should be noted that when the analysis target is a multilayer film or the like,
When calculating the thickness of several sets and the content of each component,
Equations (7) to (12) are a plurality of simultaneous equations. here
In the convergence judgment, the thickness T or the content ratio is determined by successive approximation.
W_iIs required to be less than a certain value.
nth theoretical strength^TI_i ⁽ⁿ⁾And n + 1 th theoretical intensity ^T
I_i ^{(n + 1)}And make sure that the amount of change is
May be determined. At this time, the conversion overlap correction conversion strength
Every time^SCI_i ⁽ⁿ⁾Is the measured intensity I_iBased on theoretical strength
Every time^TI_i ⁽ⁿ⁾And check the reliability of the results.
You.

Next, a method according to the second embodiment of the present invention will be described. In the apparatus used in the method of the second embodiment, as shown in FIG. 2, as compared with the apparatus used in the method of the first embodiment shown in FIG. Instead of the following correction constant storage means 1
8, the difference is that a calibration curve storage means 11 and a calibration curve application means 14 are included. The correction constant storage means 18
A theoretical matrix correction constant for the absorption and excitation of fluorescent X-rays calculated based on the theoretical intensity of fluorescent X-rays to be generated from a plurality of samples whose composition is assumed is stored.

The calibration curve storage means 11 stores the measured intensity of the fluorescent X-ray 6 generated and measured from each component in the plurality of standard samples 3 having different compositions and the content of the component in the standard sample 3. As a correlation with the above, a calibration curve previously obtained by correction using the theoretical matrix correction constant is stored for each component. The calibration curve applying means 14
Calculates the content of each component in the sample 13 by applying the calibration curve to the measured intensity stored in the measuring means 12. Here, the calibration curve stored in the calibration curve storage means 11 is a fluorescence X-ray having a spectrum at least partially overlapping the spectrum of the fluorescent X-ray to be measured, and the fluorescence X-ray to be measured The effect of the disturbing line on the line has been corrected using the theoretical matrix correction constant. Note that the calibration curve applied by the calibration curve application unit 14 includes a theoretical matrix correction constant, and a specific numerical value may be retrieved from the correction constant storage unit 18 and used.

The method of the second embodiment using this apparatus is as follows.
The method belongs to the SFP method, and is applied only to a bulk sample, and the content W _{i of} each component is obtained. First, the theoretical intensity of fluorescent X-rays to be generated from a plurality of samples whose compositions are assumed is calculated by the method disclosed in Japanese Patent Application No. 9-12336, for example. Calculate the theoretical matrix correction constant α _ij for excitation,
It is stored in the correction constant storage unit 11.

Further, primary X-rays 2 are radiated to a plurality of standard samples 3 having different compositions, and each component i in the standard sample 3 is illuminated.
The intensity I _i of the fluorescent X-rays 6 generated from the measurement is measured, and the correlation between the measured intensity I _i and the content W _i of the component i in the standard sample 3 is calculated for each component i by the theoretical matrix correction constant α. The influence of the absorption and excitation of the fluorescent X-ray by the coexisting element is determined using _ij as a calibration curve corrected (matrix corrected) and stored in the calibration curve storage unit 11 in advance. Here, in obtaining the calibration curve, a fluorescent X-ray having a spectrum at least partially overlapping with the spectrum of the fluorescent X-ray to be measured is regarded as an interference line, and the interference from the interference component k with respect to the fluorescent X-ray to be measured is determined. The influence of the line is corrected using the theoretical matrix correction constants α _ij and α _kj . Specifically, the calibration curve is represented by, for example, the following equation (13).

[0053] _{W i = (a i I i} 2 + b i I i + c i) (1 + Σα ij W j) -Σ 4 γ ik {(1 + Σα ij W j) / (1 + Σα kj W j)} W k ... (13 )

This equation (13) is derived as follows. First, a calibration curve without overlap correction is given by the following equation (14).
Indicated by

W _i = (a _i I _i ² + b _i I _i + c _i ) (1 + Σα _ij W _j ) (14)

Here, Lachan is used for matrix correction.
When the theoretical matrix correction of the ce correction constant is used, Expression (14) can be rewritten as Expression (15). Note that I _ip
Is the measured intensity of the pure substance of component (element) i.

W _i = (I _i / I _ip ) 100 (1 + Σα _ij W _j ) (15)

[0058] thereto, the addition of correction overlap in a manner to correct the measured intensity I _i, the following equation (16).

[0059] _{W i = {(I i -Σ} 5 γ ik I k) / I ip)} 100 (1 + Σα ij W j) ... (16)

Here, ⁵ γ _ik is an overlap correction coefficient, which corrects the measured intensity I _i of the fluorescent X-ray to be measured using the measured intensity I _k of the disturbing line. And a constant that does not depend on the sensitivity of the device. Now,
Content W _k and the measured intensity I _k of interfering components k, the relationship of I _kp, like Equation (15), represented by the following formula (17).

W _k = (I _k / I _kp ) 100 (1 + Σα _kj W _j ) (17)

By substituting I _k obtained by this equation into the above equation (16), and further transforming it into the following equation (18),
Equation (19) is obtained.

[0063] ^{_{6 γ ik = 5 γ ik I}} kp / I ip ... (18)

[0064] _{W i = (I i / I} ip) 100 (1 + Σα ij W j) -Σ 6 γ ik {(1 + Σα ij W j) / (1 + Σα kj W j)} W k ... (19)

The overlap correction coefficient ⁶ γ _ik is also _calculated by the equation (1)
As is apparent from 8), similarly to the overlap correction coefficient ⁵ gamma _ik of Equation (16) is a constant that does not depend on the sensitivity of the device on the composition of the sample. The matrix correction of equation (19)
Reverting to the form of Equation (14), Equation (13) is obtained.

[0066] _{W i = (a i I i} 2 + b i I i + c i) (1 + Σα ij W j) -Σ 4 γ ik {(1 + Σα ij W j) / (1 + Σα kj W j)} W k ... (13 )

That is, the overlap correction coefficient ⁴ γ _ik used in the method of the second embodiment is also the same as the overlap correction coefficient ⁶ γ _ik in the equation (19), and thus the overlap correction coefficient ⁵ γ _{ik in the} equation (16). Similarly to the above, the constant is independent of the composition of the sample and the sensitivity of the apparatus.

The equation (1) showing the calibration curve of the method of the second embodiment
3) and Equation (3) showing the calibration curve of the conventional SFP method described above, it can be seen that each overlap correction coefficient ⁴ γ _ik ,
² gamma _ik it is understood that a relationship represented by the following formula (20).

[0069] _{W i = (a i I i} 2 + b i I i + c i) (1 + Σα ij W j) -Σ 2 γ ik W k ... (3)

[0070] ^{_{2 γ ik = 4 γ ik {}} (1 + Σα ij W j) / (1 + Σα kj W j)} ... (20)

That is, in the conventional SFP method, the overlap correction coefficient ² γ _{ik to} be used is correctly determined by the composition W of the sample 13.
_Although it depends on _j , since it was treated as a constant, accurate overlap correction could not be performed.

On the other hand, according to the method of the second embodiment, in obtaining the calibration curve, that is, the equation (13) in the SFP method, the influence of the interference line on the fluorescent X-ray to be measured is strictly theoretically determined. Matrix correction constants α _ij , α
Correct using _kj . That not only the correction coefficient ⁴ gamma _ik overlap content W _k interfering components k correction term {(1 + Σα _ij
W _j ) / (1+ _{ α _kj W _j )}, so that the overlap correction coefficient does not depend on the device sensitivity or the sample composition.
It can accurately overlap correction using the ⁴ gamma _ik. Therefore, in the apparatus to be used, in addition to the theoretical matrix correction constant α _ij conventionally stored for matrix correction, an overlap correction coefficient ⁴ γ _ik independent of the apparatus sensitivity and the composition of the sample may be stored. Accurate overlap correction can be performed without finding an overlap correction coefficient for each sample type.

In the apparatus in which the calibration curve obtained in this way is stored in the calibration curve storage means 11, the measuring means 1
2 irradiates the sample 13 with primary X-rays 2
The intensity I _i of the fluorescent X-ray generated from each component i in the inside is measured and stored. Then, the calibration curve applying unit 14 applies the above-mentioned calibration curve to the measured intensities I _i to determine the content W _i of each component in the sample 13.

In the methods of the first and second embodiments, for example, the fluorescent X-ray to be measured is a P-Kα ray, and a constant for calculating the theoretical intensity for the interference line Mo-Ll is prepared. May not be. In such a case, the theoretical strength of the adjacent X-ray fluorescence for example Mo -Eruarufa radiation of a wavelength in the interference line Mo -Ll line the same sequence is used as the ^T I _k. Thus, even when a constant for calculating the theoretical strength of the disturbance line is not prepared, accurate overlap correction can be performed using the overlap correction coefficient independent of the device sensitivity or the like.

Further, it is shown by simple calculation that the overlap correction coefficients ³ γ _ik and ⁴ γ _ik in the methods of the first and second embodiments have the relationship of the following equation (21).

[0076] ^{_{3 γ ik = 4 γ ik (}} T I ip / T I kp) ... (21)

[0077] Here, ^T I _ip is the theoretical strength of the pure substance of the component (element) theoretical strength of the pure substance i, ^T I _kp is interfering components (elements) k, obtained by both calculations. In other words, it is possible in terms between the two overlap correction factor ^{3 γ} _ik, ^{4 γ} _ik. Therefore, a certain device, first, when configured as a device used in the method of the second both embodiments, both the overlap correction coefficient ³ gamma _ik, ⁴ gamma no need to store in search of _ik, either If one is obtained and stored, the other is obtained by conversion according to the equation (21).

[0078]

As described above in detail, according to the present invention, the fluorescent X-ray is measured based on the measured intensity of the fluorescent X-ray from the sample.
In the X-ray fluorescence analysis method and apparatus for determining the content of each component in a sample using the theoretical intensity calculated for the X-ray, an accurate overlap using an overlap correction coefficient independent of the apparatus sensitivity and the composition of the sample. Can be corrected.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an apparatus used for a fluorescent X-ray analysis method according to a first embodiment of the present invention.

FIG. 2 is a schematic view showing an apparatus used for a fluorescent X-ray analysis method according to a second embodiment of the present invention.

[Explanation of symbols]

1: X-ray source, 2: primary X-ray, 3: standard sample, 6: fluorescent X
Reference numeral 8: sample stage, 10: detection means, 11: calibration curve storage means, 12: measurement means, 13: sample, 14: calibration curve application means, 16: calculation means, 18: correction constant storage means.

Claims (6)

[Claims] 1. A sample is irradiated with primary X-rays, the intensity of fluorescent X-rays generated from each component in the sample is measured, and the intensity based on the measured intensity and the thickness or the content of each component in the sample are measured. Using the theoretical intensity of the fluorescent X-ray of each component calculated assuming at least one of the rates, the assumed thickness or the content rate of each component is successively and approximately corrected so that both intensities match. In the X-ray fluorescence analysis method for calculating at least one of the thickness or the content of each component, the X-ray fluorescence having a spectrum at least partially overlapping the spectrum of the X-ray to be measured is regarded as an interference line. The converted intensity is converted to a theoretical intensity scale to obtain a converted intensity, and the converted intensity is corrected using the theoretical intensity of the disturbing line calculated assuming at least one of the thickness and the content of each component. Before X-ray fluorescence analysis method, characterized in that to be based on the measured intensity strength. 2. A sample is irradiated with primary X-rays to measure the intensity of fluorescent X-rays generated from each component in the sample, and the intensity based on the measured intensity and the thickness or the content of each component in the sample are measured. Using the theoretical intensity of the fluorescent X-ray of each component calculated assuming at least one of the rates, the assumed thickness or the content rate of each component is successively and approximately corrected so that both intensities match. In the X-ray fluorescence analysis method for calculating at least one of the thickness or the content of each component, the X-ray fluorescence having a spectrum at least partially overlapping the spectrum of the X-ray to be measured is regarded as an interference line. The measured intensity is converted into a theoretical intensity scale to obtain a converted intensity, and the theoretical intensity of the disturbing line or the wavelength in the same series as the disturbing line is calculated assuming at least one of the thickness and the content of each component. Using theoretical strength of adjacent fluorescent X-ray, X-ray fluorescence analysis method characterized in that the intensity based on the measured intensity by correcting the conversion strength. 3. Calculating the theoretical intensity of fluorescent X-rays to be generated from a plurality of samples assuming the composition, calculating a theoretical matrix correction constant for absorption and excitation of the fluorescent X-ray based on the theoretical intensity, A plurality of known and different standard samples are irradiated with primary X-rays, the intensity of fluorescent X-rays generated from each component in the standard sample is measured, and the correlation between the measured intensity and the component content in the standard sample is measured. The relationship is determined in advance as a calibration curve corrected using the theoretical matrix correction constant for each component, and the sample is irradiated with primary X-rays, and the intensity of fluorescent X-rays generated from each component in the sample is measured. In the fluorescent X-ray analysis method for determining the content of each component in the sample by applying the calibration curve to the measured intensities, the spectrum of the fluorescent X-ray to be measured at least partially overlaps X-ray fluorescence analysis comprising: using a fluorescent X-ray having a spectrum as an interference line; and obtaining the calibration curve by correcting the influence of the interference line on the fluorescent X-ray to be measured using the theoretical matrix correction constant. Method. 4. A sample stage on which a sample is fixed, an X-ray source for irradiating the sample with primary X-rays, detection means for measuring the intensity of fluorescent X-rays generated from the sample, Irradiating primary X-rays from the sample, causing the detecting means to measure the intensity of the fluorescent X-rays generated from each component in the sample, and measuring means for storing the measured intensities. Based on the theoretical intensity of the fluorescent X-rays of each component calculated assuming at least one of the thickness or the content of each component in the sample, so that both intensities match, the assumed thickness or Calculating means for sequentially and approximately correcting and calculating the content of each component, and calculating at least one of the thickness or the content of each component, wherein the calculation means comprises a spectrum of a fluorescent X-ray to be measured. Specs that at least partially overlap with Fluorescent X with Le
Line as a disturbing line, the measured intensity stored in the measuring means is converted to a theoretical intensity scale to be a converted intensity, and the theoretical value of the disturbing line calculated by assuming at least one of the thickness or the content of each component. An X-ray fluorescence spectrometer that corrects the converted intensity using the intensity to obtain an intensity based on the measured intensity. 5. A sample stage on which a sample is fixed, an X-ray source for irradiating the sample with primary X-rays, detection means for measuring the intensity of fluorescent X-rays generated from the sample, and an X-ray source for the sample. Irradiating primary X-rays from the sample, causing the detecting means to measure the intensity of the fluorescent X-rays generated from each component in the sample, and measuring means for storing the measured intensities. Based on the theoretical intensity of the fluorescent X-rays of each component calculated assuming at least one of the thickness or the content of each component in the sample, so that both intensities match, the assumed thickness or Calculating means for sequentially and approximately correcting and calculating the content of each component, and calculating at least one of the thickness or the content of each component, wherein the calculation means comprises a spectrum of a fluorescent X-ray to be measured. Specs that at least partially overlap with Fluorescent X with Le
A line as a disturbing line, the measured intensity stored in the measuring means is converted to a theoretical intensity scale to obtain a converted intensity, and the theoretical value of the disturbing line is calculated assuming at least one of the thickness and the content of each component. An X-ray fluorescence spectrometer that corrects the converted intensity by using the intensity or the theoretical intensity of X-ray fluorescence having the same series as the disturbing line and having a wavelength close to each other to obtain an intensity based on the measured intensity. 6. A sample stage on which a sample is fixed, an X-ray source for irradiating the sample with primary X-rays, detection means for measuring the intensity of fluorescent X-rays generated from the sample, and a plurality of Correction constant storage means for storing a theoretical matrix correction constant for the absorption and excitation of fluorescent X-rays calculated based on the theoretical intensity of fluorescent X-rays to be generated from the sample; As a correlation between the measured intensity of the fluorescent X-rays generated and measured from each of the components and the content of the component in the standard sample, for each component,
Calibration curve storage means for storing a calibration curve obtained in advance by correcting using the theoretical matrix correction constant; and irradiating the sample with primary X-rays from the X-ray source, and generating fluorescence from each component in the sample. A measuring means for causing the detecting means to measure the intensity of X-rays, and storing the measured intensities; and a calibration method for applying the calibration curve to the measured intensity stored in the measuring means to determine the content of each component in the sample. A calibration curve stored in the calibration curve storage means, the fluorescence X-ray having a spectrum at least partially overlapping with the spectrum of the fluorescent X-ray to be measured is measured as an interference line. An X-ray fluorescence spectrometer, wherein the influence of disturbing rays on X-ray fluorescence to be corrected is corrected using the theoretical matrix correction constant.