JPS61194359A - Method for analysis of element in specimen by using crucible - Google Patents

Abstract

PURPOSE:To smoothly perform analysis with good accuracy, by performing the primary degassing of only a crucible under heating and subsequently charging flux in the crucible to perform secondary degassing. CONSTITUTION:A plate shaped shutter 63 is slid to form an open state and flux F and a specimen S are charged from charge ports 64b', 64c'. Next, upper and lower electrodes 10, 20 are closed so as to hold an analytical crucible C therebetween and a current is supplied to the crucible C to perform primary degassing. Subsequently, when a cylindrical shutter 42 is brought to an open state, the flux F is fallen in the crucible C and secondary degassing is performing by the short-time supply of a current in power consumption lower than that in primary degassing. In the next step, when the cylindrical shutter 42 is brought to an open state for the sake of the analysis of the specimen S, said specimen S is fallen in the crucible C and heated along with the flux F while the generated gas is sent to an analyser along with carrier gas.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention involves placing a sample of metal or the like in a crucible, melting the sample by directly applying electricity to the crucible, and analyzing the gas generated at that time. Concerning methods for analyzing elements contained in samples.

<Prior art> Generally, in the analysis of elements in a sample using a crucible, gold such as 3n, Ni, Fe, Pt, etc. is placed in the crucible as a 1ri-7 lux (bath agent), and then added to the crucible. During analysis, a heavy electric power is applied for a long time to degas the crucible and the flux, and then the sample is placed in the crucible, and electric power is applied to the crucible again to melt the sample in the presence of the flux. (See Figure 7).

When flux is used in this way, (1) the elements in the sample and 7 lux are combined to form a so-called alloy state, lowering the melting point and making it easier to extract the elements as a gas; (2)
By mixing the molten sample and flux, the viscosity decreases and the extraction of gas etc. is promoted; ■M
For metals such as n, high temperatures (2500 to 3000°C
), the metal vapor recombines with other metal vapors, causing a so-called getter phenomenon, but in such cases, the occurrence of the getter phenomenon can be effectively prevented by increasing the vapor pressure by using Sn as a flux. It has the effect of smooth extraction of gas, etc.
Gas extraction in the analysis is facilitated and made more efficient.

However, in conventional analysis of this kind, the flux is placed in a crucible from the start of degassing and heated with high power for a long period of time. It was violently scattered inside, and N1. Fluxes such as PE and PT permeate the crucible during heating and melting, and are not able to function as bath agents during analysis.As a result, gas extraction cannot be performed smoothly, and the analysis could have a serious impact on

<Problems to be Solved by the Invention> The present invention has been made with the above-mentioned matters in mind. The purpose of the present invention is to fully utilize the function of the flux as a bath agent by preventing the flux from causing any damage, thereby enabling smooth and accurate elemental analysis in a sample.

<Means for solving the problems> In order to achieve the above-mentioned object, the present invention first provides the following:
Primary degassing is performed by heating only the crucible at a high temperature, and then flux is introduced into the crucible and heated at a lower temperature than during the primary degassing to perform secondary degassing.

In this way, by first heating only the crucible to a higher temperature than the temperature at the time of analysis to perform primary degassing, then pouring the flux into the crucible and heating it at a lower temperature than during the primary degassing. Since the heating time of the flux can be shortened and the heating temperature can be lowered, scattering of the flux and penetration into the crucible are extremely reduced. As a result, the flux can fully fulfill its function as a bath agent during analysis.

<Example> Hereinafter, one embodiment of the present invention will be described based on the drawings.

1 to 4 show an apparatus for analyzing elements in a sample for carrying out the method of the present invention, particularly the vicinity of a charging device for charging flux F and sample S into a crucible.

10 is an upper electrode fixed by the extraction furnace body 1, and 10 is a lower electrode which is driven up and down by the cylinder 2.

The upper electrode 10 has an electrode surface 1 that contacts the opening edge of C.
1, and an electrode surface 21 that contacts the bottom of the ruribo C is formed on the lower electrode surface, and both electrode surfaces 11,
21, the crucible C is directly energized to generate Joule heat, the sample S accommodated in the crucible C is melted in the presence of flux F, and the generated gas is converted into an inert carrier gas. The structure is such that it is loaded onto the wafer and sent to an analyzer not shown. 12 is a descending hole provided in the upper electrode (2).

(9) is a feeder block installed on the upper part of the upper electrode 10, and there are two mutually parallel blocks passing horizontally from the front side (X side in Fig. 2) to the rear side (also Y side). The horizontal holes 31 and 32, and the upper part facing the upper surface side (first side) and intersecting with the horizontal holes 31 and 32, respectively, a hole 330,
340 further extends downward and merges with the vertical hole 3 of 19.
Lower holes 33D and 34D forming holes 5 are opened. In addition, upper and lower hole adjustment (33U and 33D).

The combination of 34U and 34D is called a fist and a pit (the former is a feather, the latter is 34).

Further, the vertical hole 35 communicates with the descending hole 12 of the upper electrode 10. And these hole adjustment 33, 34. Vertical hole 35
The drop hole 12 is a hole through which a flux F and a sample S dropped by loaders 40F and 40S, which will be described later, pass, and also functions as a flow path for the carrier gas described above.

4QF and 4QS are loaders that are inserted into the horizontal holes 31 and 32, and temporarily hold the flux F1 sample S introduced from the input section, which will be described later.
34, the vertical hole 35, and the drop hole 12 to charge the flux F and the sample S into the crucible C. Since both loaders 4QF and 4QS are made of the same parts and have the same configuration, for convenience, only the loader on the sample side will be explained at first glance 7: 41 is a guide shaft and has 7 langes 41a at the front end. A male screw portion 41b1 and a notch portion 4ic are formed at the rear end. A holding hole 414 is provided in the intermediate portion of the shaft in the diametrical direction. The shutter is a cylindrical shutter fitted so as to be able to slide on the guide shaft 41. A spring receiver 421L is provided at the front end of the shutter, and a connecting rod is connected to the rear end via a support pin material. ing. And the cylindrical shutter C
An upper elongated hole 42 is located at a 180° different position on the outer peripheral wall 4z.
b and a lower opening 42c are opened. 45 is a spring interposed between the stepped portion 41'3 of the guide shaft 410 and the spring receiver 42a of the cylindrical shutter 42, and presses and biases the cylindrical shutter C in the Y direction; 41t
) is screwed on to prevent the cylindrical shutter string from coming off in the Y direction, and 47 is an O-ring.

The nine loader 40S constructed as described above is fitted into the horizontal hole 32 of the loading machine block (9) and fixed to the loading machine block with a set screw. The upper side of the holding hole 41d of the guide shaft 41 is always in communication with the upper adjusting hole 34U via the upper long hole 42b of the cylindrical shutter 42, but the lower side of the holding hole 41d is connected to the peripheral wall of the cylindrical shutter 420. The holding hole 41d, the upper elongated hole 42tl and the lower part are closed so that they communicate with the upper side of the lower hole 34D through the lower opening 420 only when the cylindrical shutter 42 is slid a predetermined distance in the X direction. The opening 42C is positioned. Further, the support pin material is guided and held by the notch 41C of the guide shaft 41, and the cylindrical shutter 42
It is configured to prevent zero rotation.

50F and 50S are cylinders for horizontally sliding the cylindrical shutters 42 of the loaders 4QF and 4QS independently of each other, and are provided on the rear side of the loading machine block force, and each rod 51F and 51S is for sliding the cylindrical shutters 42 of the loaders 4QF and 4QS in the horizontal direction.
.

Each is connected to a 4O8 connecting rod core.

Reference numeral 60 denotes a loading section provided above the loading machine block (9), and the flux F1 sample S is loaded into the loader 4OF.

40S, and is configured as follows, for example. Reference numeral 61 denotes a base plate fixed by a retaining part 37 formed on the upper surface of the feeding machine block (material), and is made of a resin material with a smooth surface such as fluororesin. This base plate 6
1, a convex surface 61L and a concave surface 61b are formed adjacent to each other, and an inclined portion 61 is formed at the end of the convex surface 61a.
a' is formed. In addition, the concave plane 61b is provided with an upper hole 33U for inserting the machine block.

Openings 611)', 611)' communicating with 34U are opened, and O-ring grooves 6tky'm61b' are provided around the respective openings 61111', 611)'. 62.62 is an O-ring. .

A plate-shaped shutter 63 slides on the uneven surface of the base plate 61 to open and close the opening 6th'+6th'. The base plate 61 is provided on the lower surface of this plate-shaped shutter 63.
A concave 1000-sided surface 63a and a convex 1000-sided surface 631) having substantially the same shape as the uneven surface are formed. The concave plane 63& has an opening 6111/ formed in the concave plane 61b of the base plate 61.

Openings 63a' and 63a' are opened corresponding to 61υ.

Reference numeral 630 denotes a connecting portion to which the rod 71 of the cylinder 70 is connected;
30' is formed.

64 is a holding member, and its flat part 64L is filled with flux F.
Input section 6 with input ports 64'+640' for 1 sample S
4b 1640 is erected, and skirt portions 64 (1, 64d) extending vertically downward are formed on both sides of the plane portion 64a. It regulates the sides of the

Reference numeral 65 denotes a presser plate, and the flat part 65a of the plate holds the input cylinder 64.
Holes 65k) and 640 are inserted through the holes 65k) and 640, respectively, and locking tools 65d and 65d having hook portions are provided on both sides of the locking tool 65d.

65'lL is a stopper 66&, 67 provided on a pair of guides 66, 67 erected on the upper surface of the feeder block Shu.
It is configured to engage with a. Said guide 66.6
7 prevents the plate-shaped shutter 63 from shifting in the lateral direction. Reference numeral 68 denotes a spring interposed between the presser plate 65 and the presser member 64, and the downward pressing force of the springs 68 and 68 causes the presser member 64 to move the upper surface portion 63 (
1 and slides integrally with the plate-shaped shutter 63. In addition, 69 is 0 formed on the upper inlet circumferential surface of the upper perforations 33U and 34U of the feeding machine block (equipment).
This is an O-ring that is fitted into the ring groove 39.

Next, we will discuss the operation of the device configured as described above in the fifth section.
The explanation will be made with reference also to FIG.

l) In the initial state, the lower openings 42Q of the cylindrical shutters 42 and 42 of the loaders 4QF and 4QS,
42Q is located at a position that does not communicate with the upper side of the lower adjustment holes 33D and 34D, so that the cylindrical shutter 42
, 42 are in a closed state. On the other hand, the plate-shaped shutter 63
The openings 63a' and 63a' are the base plate 61.
Since it is in a position out of communication with the openings 61 and 611)', it is in a closed state (see FIG. 5 (N)).

2) Next, when the cylinder 70 operates and the plate-shaped shutter 63 slides a predetermined distance in the X direction in FIG.
3a', 63a' and 611)', 61b' are not in communication, and the plate-shaped shutter 63 is in an open state. As a result, the input cylinder 6411++6+c-opening 63a', 63a
'-Opening 6111ft611f'-Upper hole adjustment 33U,
34U-Holding hole 41d #41 (l is in communication state. At this time, of course, the lower portions of the cylindrical shutters 42, 42 are in the closed state (see FIG. 5 (0, FIG. 2)).

As mentioned above, when the plate-shaped shutter 63 slides,
Since uneven surfaces are formed on the lower surface of the shutter 63 and the upper surface of the base plate 61, the O-ring groove 6 of the base plate 61
The O-rings 62, 62 for sealing provided in 117'' and 61υ' are not rubbed against the lower surface of the plate-shaped shutter 63.

3) When the plate-shaped shutter 63 is in the open state, when the flux F1 and the sample S are inputted from the input ports 64W and 64d, these fluxes F and the sample S are transferred to the guide shaft 41.
Since the lower side of the holding hole 41dl41+1 is closed, the holding hole 41dl41+1 is temporarily held in the loader 40F, 40S (see FIG. 5).

4) Next, the lower electrode 20 is lowered by the cylinder 2, the crucible C for analysis is placed on the electrode surface 21, and the cylinder 2 is raised to sandwich the crucible C between the upper electrode 10 and the lower electrode. Both electrodes 10.20 are closed in this manner.

Then, a control switch not shown in Figure 1 is turned on to energize the crucible C. In this case, the electric power used to heat the crucible C is greater than that during analysis.

In addition, it is energized for a long time (see FIG. 6). The primary degassing is performed in this way, and the temperature is approximately 2500℃.
~3000°C.

On the other hand, at the same time as the upper electrode IO1 lower electrode is closed, the cylinder 70 is returned to its original position and the plate-shaped shutter 63=t-
Slide it in the Y direction to close it again. Even during this sliding, the bottom surface of the plate-shaped shutter 63 is 0.
Of course, the rings 62, 62 will not be rubbed. In this way, the plate-shaped shutter 63 is closed, and in that state, the carrier gas is sent into the upper adjustment holes 33U and 340 to close the loader 4OF.

7 lux F in 40S, sample S is purged by the carrier gas.

5) When the primary degassing is completed, the cylinder 50F is operated, and the cylindrical MW rasher 42 of the loader 40F is slid by a predetermined distance in the X direction so that its lower opening 42Q is on the lower side of the holding hole 41d of the guide shaft 41 and to match the upper side of the lower hole adjustment 33D of the feeder block (9),
When the cylindrical shutter is opened, the holding hole 41d is communicated with the opening of the crucible C via the drop hole 12 of the upper electrode 10. As a result, the flux F held in the holding hole 41 (1) is sufficiently heated and +1+-IA'2F(''
Yufdf? −+ z (! l; l?L(”+
#Fm)) After this flux F is injected into Rupo C, secondary degassing is subsequently performed, but unlike the primary degassing, electricity is applied at low power and for a short period of time. This completes the degassing of the flux (see Figure 6). The temperature of this secondary degassing is relatively lower than the temperature of the primary degassing, for example about 2000 to 2500°C.

Note that after the flux F is introduced, the cylindrical shutter 42 returns to the closed state.

6) Next, when heating the crucible C again for sample analysis, the cylinder 50S operates and the cylindrical shutter 42 of the loader 40S is opened in the same manner as when the flux was introduced above, and the sample S is heated. Fall into crucible C (Fig. 5 0
reference). Then, it is heated (approximately 2000 to 2500°C) together with the flux F already contained in the crucible C.
In this embodiment, as shown in FIG. 6, the temperature is set to be approximately the same as the temperature during the secondary degassing, but it is not necessarily necessary to set the temperature to be approximately the same. ) Strong shoulders generate dregs. This generated gas is carried on a carrier gas and sent to an analysis needle (not shown), where a predetermined gas analysis is performed.

In the above embodiment, the sample S may be made of other materials such as ceramics in addition to metal. Furthermore, an inert gas such as helium is used as the carrier gas.

Furthermore, in the embodiment described above, two loaders 4QF and 4QS that are driven individually are provided, and the flux F1 sample S is separately accommodated in each loader before energization to the crucible C. First, set up 7 lux F.
is housed in the loader to perform primary degassing by heating the crucible C, and after completion of this degassing, the flux F is introduced into the crucible C to continue secondary degassing, while
The sample S may be placed into a loader, and the sample S may be placed into a crucible C after secondary degassing is completed. In this case, the applied power and energization time are set in the same manner as in the above embodiment.

Note that the method of the present invention is not limited to that described in the above embodiments, and includes, for example, the following modifications.

■ After primary degassing and secondary degassing, when putting the sample into the crucible, you can also put in not only the sample but also a second 7 lux (a different flux than that put in during the secondary degassing). good.

■ When adding flux after primary degassing,
Samples may be added at the same time. In this case, there is an advantage that the background in the sample can be eliminated (interfering components removed) during the secondary degassing. In this case, the temperature during the secondary degassing must be lower than the temperature during the subsequent sample analysis, so that the component to be measured in the sample becomes a gas during the secondary degassing. It is necessary to set the temperature so that it does not occur.

<Effects of the Invention> As detailed above, in the method of the present invention, first, only the crucible is heated at a high temperature to perform secondary degassing, and then flux is introduced into the crucible to perform the secondary degassing during the primary degassing. Since secondary degassing is performed by heating at a low temperature, during primary degassing, the crucible itself is mainly degassed, and during secondary degassing, degassing is mainly done from the flux. , degassing will be carried out effectively. Moreover, secondary degassing after flux injection is performed with lower power than primary degassing, so
There is no possibility that the molten flux will be scattered outside the crucible or penetrate into the crucible. For this reason,
When analyzing a sample, the flux can fully perform its function as a bath agent, and the analysis can be performed smoothly and accurately. According to the method of the present invention, high purity,
There are many fluxes that can be used other than high-quality FRANXX, and the blank value of the flux can be extremely reduced, which not only improves analysis accuracy but also reduces analysis running costs.

[Brief explanation of drawings]

Figures 1 to 3 show the main structure of an elemental analyzer for carrying out the method of the present invention, and Figure 1 is a cross-sectional front view;
Figure 2 is a sectional side view, Figure 3 is a partially sectional plan view,
FIG. 4 is an exploded perspective view showing the main structure of the charging device, FIGS. 5 and 6 are diagrams for explaining the operation, and FIG. 7 is a diagram for explaining the conventional method. DESCRIPTION OF SYMBOLS 10... Upper electrode, 20... Lower electrode, C... Crucible, S... Sample, F... Flux. Figure 2 Figure 3

Claims (1)

[Claims] A sample such as a metal and a flux are placed in a crucible held between an upper electrode and a lower electrode, and electricity is applied directly to the crucible to heat it and melt the sample, and the elements in the sample are analyzed. The method is characterized in that first, only the crucible is heated at a high temperature to perform primary degassing, and then flux is introduced into the crucible and heated at a lower temperature than that during the primary degassing to perform secondary degassing. A method for elemental analysis in samples using a crucible.