Lead-free high-Curie temperature PTCR (positive temperature coefficient resistor) ceramic material and preparation method thereof

A ceramic material and solution technology, which is applied in the field of lead-free semiconductor materials, can solve the problems of difficult semiconducting of samples, reduction of carrier concentration, increase of Curie temperature, etc., and achieves small powder particle size range, dense ceramic structure, The effect of high purity

Inactive Publication Date: 2013-01-23
TIANJIN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

These factors reduce the concentration of carriers in the sample, making it difficult for the sample to semiconduct, which limits the increase in the Curie temperature

Method used

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  • Lead-free high-Curie temperature PTCR (positive temperature coefficient resistor) ceramic material and preparation method thereof
  • Lead-free high-Curie temperature PTCR (positive temperature coefficient resistor) ceramic material and preparation method thereof
  • Lead-free high-Curie temperature PTCR (positive temperature coefficient resistor) ceramic material and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Take x=0. Present embodiment is according to above-mentioned mol ratio batching, concrete steps are:

[0028] (1) According to the molar ratio of citric acid: distilled water = 1:15, weigh citric acid, dissolve it in distilled water, and heat it in a water bath at 80°C until it is completely dissolved, as solution A.

[0029] (2) According to the molar ratio of butyl titanate: alcohol = 1:8, take butyl phthalate and dissolve it in alcohol as solution B;

[0030] (3) Measure solution A and solution B according to the molar ratio of citric acid: butyl titanate = 2:1, add ammonia water to adjust the pH of solution A to 7, drop solution B into solution A, and place in a water bath at 80°C Heat and stir in the pot for 1 hour, and seal the mouth of the container with a cover to prevent solute precipitation due to a large amount of volatilization of the solvent. When the following steps need to add substances to the container, temporarily remove the cover, and re-seal it imme...

Embodiment 2

[0038] Take x=0.04. According to the above mol ratio ingredients in this implementation example, the concrete steps are:

[0039] (1) Weigh citric acid according to the molar ratio of citric acid: distilled water = 1:20, dissolve it in distilled water, and heat it in a water bath at 80°C until it is completely dissolved, as solution A.

[0040] (2) According to the molar ratio of butyl titanate: alcohol = 1:10, take butyl phthalate and dissolve it in alcohol as solution B;

[0041] (3) Measure solution A and solution B according to the molar ratio of citric acid: butyl titanate = 2:1, add ammonia water to adjust the pH of solution A to 7, drop solution B into solution A, and place in a water bath at 80°C Heat and stir in the pot for 1 hour, and seal the mouth of the container with a cover to prevent solute precipitation due to a large amount of volatilization of the solvent. When the following steps need to add substances to the container, temporarily remove the cover, and re...

Embodiment 3

[0049] Take x=0.05. According to the above mol ratio ingredients in this implementation example, the concrete steps are:

[0050] (1) According to the molar ratio of citric acid: distilled water = 1:25, weigh citric acid, dissolve it in distilled water, and heat it in a water bath at 80°C until it is completely dissolved, as solution A.

[0051] (2) Dissolve butyl phthalate in alcohol according to the molar ratio of butyl titanate: alcohol = 1:12, as solution B;

[0052] (3) Take solution A and solution B according to the molar ratio of citric acid: butyl titanate = 2:1, add ammonia water to adjust the pH of solution A to 8, drop solution B into solution A, and place in a water bath at 80°C Heat and stir in the pot for 1 hour, and seal the mouth of the container with a cover to prevent solute precipitation due to a large amount of volatilization of the solvent. When the following steps need to add substances to the container, temporarily remove the cover, and re-seal it immed...

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Abstract

The invention relates to a lead-free high-Curie temperature PTCR (positive temperature coefficient resistor) ceramic material and a preparation method thereof. The composition of the ceramic material is of Ba1-x (Bi0.5Na0.5)xTiO3, wherein x is not less than 0 and not more than 0.06. A sol-gel method is adopted for preparing the lead-free PTCR material and the method, the sintering temperature of a traditional solid-phase reaction method is too high, when the temperature is above 1300 DEG C, BNT (Bi0.5Na0.5TiO3) is very easy to decompose during the sintering process, and the material is further difficult to be semi-conducted; and by adopting the sol-gel method according to the invention, the sintering can be performed at the temperature of 1250 DEG C, and the sintering temperature is reduced. When the BNT content is more than 2mol%, the sintering and the semi-conduction can not be performed in an air atmosphere by using the traditional solid-phase reaction method, and the sintering needs to be performed under a reducing atmosphere. However, when the BNT content is 5mol%, the material still has the properties of a semi-conductor by using the method disclosed by the invention, and the Curie temperature is obviously increased.

Description

technical field [0001] The invention relates to a novel positive temperature coefficient thermistor material and a preparation method thereof. A lead-free positive temperature coefficient thermistor ceramic with a high Curie temperature (Tc>120°C) is prepared by a sol-gel method, which belongs to a lead-free semiconductor material field. Background technique [0002] It is well known that BaTiO modified by doping 3 Ceramics show good positive temperature coefficient characteristics. As an important basic control element, ceramics have been widely used in various fields such as electronics, machinery, medical and health, agriculture, food, and household appliances. They can be used to manufacture various automatic constant temperature Heating element, starting switch element, overcurrent and overheating protection element and temperature sensor for side heat information induction, etc. We know that BaTiO 3 The Curie point is 120°C, so BaTiO 3 The application temperatur...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/468C04B35/622
Inventor 杨德安李海龙曲远方
Owner TIANJIN UNIV
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