W-type low-and-medium temperature NTC-PTC binary composite thermistor material and preparation method thereof

Abstract

The invention relates to a W-type low-and-medium temperature NTC-PTC binary composite thermistor material and a preparation method thereof and belongs to the technical field of the preparation process of the low-temperature thermistor material. The material consists of (1-omega)La2 / 3Sr1 / 3MnO3+omegaLa1.85Sr0.15CuO4, wherein omega is equal to 0.015 to 0.025mol percent. The preparation process is a solid-phase synthesis process. The preparation process of the W-type low-and-medium temperature NTC-PTC binary composite thermistor material comprises steps of selecting components, blending a main-phase component and doping components in a certain proportion, grinding, calcining, sintering and the like, and finally blending, grinding and sintering the main-phase component and the doping components, and the like. A good binary composite thermistor material can be obtained in a relatively wide temperature range at the low temperature. The material can be used at the temperature of between 2 and 380k, has a relative low resistivity, contains no toxic substance, namely lead, is environment friendly and is applicable in the field of space equipment and low temperature measuring apparatus equipment.

Description

technical field [0001] The invention relates to a W-type medium and low temperature NTC-PTC double composite thermistor material and a preparation method thereof, belonging to the technical field of low temperature thermistor material preparation technology. Background technique [0002] Thermistor materials include negative temperature coefficient thermistor (NTCR), positive temperature coefficient thermistor (PTCR), and critical temperature coefficient resistor (CTR). When the thermistor made of thermistor material is used as a single component with a single function, there are the following disadvantages: for NTC materials, the resistance gradually decreases due to self-heating under overvoltage, and there is a possibility of breakdown; for PTC materials, due to The resistance value is small at room temperature, so when it is energized and self-heated as a heater, its performance stability and service life will be affected due to the large impact current. For this reason...

AI Technical Summary

Problems solved by technology

When the thermistor made of thermistor material is used as a single component with a single function, there are the following disadvantages: for NTC materials, the resistance gradually decreases due to self-heating under overvoltage, and there is a possibility of breakdown; for PTC materials, due to The resistance value is small at room temperature, so when it is energized and self-heated as a heater, its performance stability and service life will be affected due to the large impact current

[0005] Chinese patent (CN 1160273A) has developed a medium and low temperature containing PbSiO 3 (Sr,Pb)TiO 3 , (Ba, Pb)TiO 3 or (Sr, Ba)TiO 3 NTC-PTC composite thermistor, but too many raw materials are involved, which is not conducive to mass production

[0006] The biggest disadvantage of the common existence of the above patents is that they all contain the toxic element Pb, which will pollute the environment and affect people's health. It is an industrial product that is not advocated by the country.

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