JPS582441B2 - Teikoutai - Google Patents

Description

Detailed Description of the Invention The present invention relates to a resistor, and by selecting its composition, a resistor whose resistivity is constant over a wide temperature range, or a resistor whose resistivity changes rapidly at a specific temperature can be produced. This is what we are trying to provide.

Conventionally, F is used as a resistor made of iron or nickel sulfide.
eS single crystal 8 and NiS single crystal are used.

However, these single crystals cannot be obtained unless they are heat-treated in a vacuum at several hundred degrees Celsius for tens to hundreds of hours, and are therefore fraught with difficulties in production.

Furthermore, in these single crystals, if you try to utilize the change in resistance value at the crystal transformation point, the mechanical strength of the crystal is weak due to the crystal distortion accompanying the transformation, and the disadvantage is that it cannot withstand repeated use. There is.

However, in the case of the porcelain used in the present invention, such crystal strain is alleviated by the action of crystal grain boundaries, and the above-mentioned defects are not observed.

However, the above-mentioned defects in mechanical strength can be eliminated by using magnetic resistors such as barium titanate semiconductor ceramics and ferrite.

However, these magnetoresistive materials have a low resistivity of 1Ωa.
It is not possible to obtain such a low resistivity (approximately 10-3 Ωcm) as in the iron, nickel, or iron-nickel sulfide porcelain according to the present invention.

Furthermore, since the sulfide ceramic resistor according to the present invention also has magnetism, it has a variety of resistivity temperature characteristics, and
It is extremely versatile.

Next, the main component is a sulfide of at least one element among iron and nickel according to the present invention, and sodium,
A resistor made of porcelain to which potassium is added will be explained.

Since the effects of adding sodium and potassium are substantially the same, examples in which sodium is added will be described below as a representative example.

The raw materials used were FeO or Fe203 powder and NiO powder.

Both powders were blended in various proportions from only FeO or Fe203 to only NiO, and sodium carbonate was added and blended.

After wet mixing these powders and drying them,
It was pressure molded into a disc shape at a pressure of 00 kg/cm2.

This molded product was placed in a carbon boat and fired in a tube furnace at a low temperature of 400 to 750°C in a carbon disulfide atmosphere for about 8 hours.

The compound composition of these porcelains was determined by chemical analysis and X-ray analysis according to various firing conditions such as each compounding composition, firing temperature, firing time, and various firing conditions such as carbon disulfide atmosphere partial pressure.

As a result of analysis, these porcelains have iron sulfide.
From FeS to Feo. 7S and also for nickel sulfide, from NiS to Nlo. Compositions up to 8S are obtained,
Solid solution ceramic compositions were also obtained with compositions between these two terminal compositions.

Similarly, this solid solution composition was confirmed to be a solid solution by Y-ray analysis and chemical analysis.

It was also confirmed that sodium was contained as an additive in these sulfide porcelains.

In iron sulfide as a raw material, when FeO is used, FeS is obtained, and when Fe203f is used, Fe1-δS (0<δ<0
．． 3) was obtained.

In these sulfide porcelains, no change in properties was observed even when a small portion of the sulfur was replaced with oxygen.

Further, even if some of these metal oxides are contained, the properties are not essentially affected.

Next, the temperature characteristics of resistivity of these sulfide porcelains are shown in the figure.

In the figure, the vertical axis represents the specific resistance measured by the four-terminal method.
Further, the horizontal axis represents the measured temperature, and the code attached to each curve represents the sample number.

Sample 1 was obtained by using as a starting material a material in which not more than 4 moles of Na2CO3 were added to 100 moles of Fe203, and firing at 700° C. for 4 hours in a carbon disulfide atmosphere.

The composition of this porcelain is as follows: N per 100 moles of Fe sulfide
a was 4 moles or less.

It was confirmed that there was almost no difference in characteristics within this range.

Sample 2 is a mixture of 90 mol of Fe203 and 10 mol of NiO as the starting material, and
This is a porcelain obtained by using 6 moles or less of No. 3 added and firing in a carbon disulfide atmosphere at 650 to 700°C for 4 hours.

Its composition is based on 100 moles of sulfides of Fe and N1,
Na content was 6.3 mol or less.

It was confirmed that within this composition range, there was almost no difference in characteristics.

Test subject 3 used a mixture of 10 moles of Fe203 and 90 moles of NiO to which 4 moles of Na2C03 was added as the starting material, and calcined it at 450°C for 7 hours in a carbon disulfide atmosphere. This is what I got.

The composition of this porcelain was 3.6 moles of Na per 100 moles of Fe and Ni sulfides, and 1 mole of Na2C03 was added to 100 moles of Ni0 as the starting material for TK Examination 4. in a carbon disulfide atmosphere,
This is porcelain obtained by firing at 400°C for 8 hours.

The composition of this porcelain is based on 100 mole parts of Ni sulfide.
Na content was 2 moles.

Test sample 5 is a porcelain obtained by using, as a starting material, 2 moles of Na2C03 added to 100 moles of Ni0, and firing at 400° C. for 8 hours in a carbon disulfide atmosphere.

The composition of this porcelain is N1 per 100 moles of N1 sulfide.
a was 4 moles.

As is clear from the figure, the specific resistance temperature characteristics of each of these samples 1 to 5 show various aspects, and the specific resistance thereof is also extremely low.

That is, sample 1 has a constant low resistivity of 1.6×10 −3 Ωcm over a wide temperature range of about −150 to +90° C., and it increases rapidly above about +90° C.

Sample 2 has a specific resistance of about 1×1 at about -150 to +40°C.
The specific resistance is constant at 0-3 Ωcm, increases above this level up to about +70°C, and gradually decreases above 70°C.

Test subject 3 has a specific resistance of approximately 0 in the temperature range of approximately +20℃ or less.
．． It is constant at 2 x 10-3 Ωcm, rapidly decreases above that level, and becomes constant at 0.08 x 10-3 Ωcm at temperatures above +70°C.

In sample 4, the resistivity decreases rapidly in the temperature range of -100 to -40°C, and gradually increases in the temperature range of -40°C or higher.

The specific resistance value is 0.3×10 −3 Ωcm at −100° C. and 0.03×10 −3 at −40° C.

Sample 5 has a specific resistance value of 0.1IXXIO up to -100℃
-3Ωcm, and above that it drops rapidly to -40℃
With the above, it becomes approximately constant at 0.02×10 −3 Ωcm.

In Example 2 above, the case where Fe203 was used as the iron oxide raw material was explained, but when FeO is used, although the specific resistance becomes somewhat larger, the tendency of the specific resistance temperature characteristics is the same as shown in the figure.

However, in FeS porcelain obtained using FeO as the starting material, the resistivity is as high as 109 Ωcm, but the temperature at which the resistivity suddenly changes and its tendency are similar to curve 1 in the figure.

Furthermore, even when potassium was used instead of sodium, the properties of the resulting porcelain showed the same tendency.

Of course, the trend was the same even when both were added.

By further adding lithium, silver, etc. to the above components, characteristics can be controlled over a wider range.

Since all of the above compositions are made of porcelain, they can be easily manufactured by the force method and have high mechanical strength, as described above.

Furthermore, these porcelains can be used not only in the temperature range where the resistivity changes rapidly, but also in a constant range of resistivity.

Furthermore, in these porcelains, especially FeO. 87
S has a large magnetization of about 20 (emu/g) and a high Curie point of about 300° C., so it is also used as a magnetic semiconductor.

A similar effect was obtained by replacing the iron or nickel blade with cobalt manganese.

In order to enhance the properties as porcelain, SiO2 and AI20
It is also effective to add 3 etc.

Although carbon disulfide is used in the production of these porcelains, a tube furnace is used and carbon disulfide can be easily removed by absorbing it with caustic soda or activated carbon at the gas outlet. There is no risk or danger of causing pollution problems.

As described above, the present invention is a resistor made of porcelain, which has as its main component a sulfide of at least one element among iron and nickel, and contains one or both of sodium or potassium. Therefore, it has high mechanical strength, has sufficiently low resistance, is easy to manufacture, and does not pose any sudden dangers that may cause pollution.

Furthermore, in addition to being used as a heat-sensitive resistor composed of a composition whose specific resistance-temperature characteristic changes rapidly, or as a resistor having a constant resistance value, its magnetism can also be used.

2. The total content of sodium and potassium with respect to the above sulfide is 10, because if sodium and potassium exceed 10 moles per 100 moles of sulfide, no significant effect will be recognized by adding them. It is desirable that the amount is less than mol.

[Brief explanation of the drawing]

The figure shows the relationship between temperature and specific resistance of an example of a resistor according to the present invention.

Claims (1)

[Claims] 1.Constructed of porcelain containing at least one of sodium or potassium in an amount not exceeding 10 moles per 100 moles of sulfate of at least one of iron and nickel. A resistor featuring: