Preparation method of rare earth cerium doped thermistor material

A technology of thermistor and rare earth cerium, which is applied in the field of preparation of thermistor materials, achieves the effect of simple steps, easy access to raw materials, and good stability

Inactive Publication Date: 2018-10-12
赵娟
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, there are more researches on the room temperature NTC thermistor with spinel structure, about Mn-Co. O binary system, after being doped with elements such as Zn and Fe, the electrical properties of the Mn-Co-O spinel phase will be improved. The ionic radii of these doped elements are generally close to the Mn ionic radii. For the system There are relatively few studies on the doping of some substances whose valence radius is obviously different from that of the main phase ions.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] (1) 5 parts of MnO, AlCl 3 2 copies, B 2 o 3 3 parts, Fe 3 o 4 5 parts, ZnO 3 5 parts, Al 2 o 3 2 parts, SiO 2 10 parts and 20 parts of spinel are placed in a ball milling tank, and then a dispersion medium is added for ball milling. The medium is a mixture of absolute ethanol, isobutanol, paraffin oil and sodium pyrophosphate, and its molar mass ratio is absolute ethanol: isobutanol: paraffin oil: sodium pyrophosphate is 7:5:5:1;

[0027] (2) Add 1 part of cerium nitrate, 4 parts of sodium oxalate, 4 parts of polyvinyl alcohol, and 1 part of 3-aminopropyltrimethoxysilane to the powder mixture in step (1) for melting, in the atmosphere protected by nitrogen gas Do high-temperature sintering in the middle, the temperature of high-temperature sintering is 800°C, the reaction time is 2h, and then naturally cool to room temperature, in which the inflow rate of nitrogen gas is 0.5L / min, and the pressure in the furnace is kept at 2Mpa;

[0028] (3) Add the reac...

Embodiment 2

[0031] (1) 6 parts of MnO, AlCl 3 3 copies, B 2 o 3 4 parts, Fe 3 o 4 6 parts, ZnO 3 6 parts, Al 2 o 3 3 parts, SiO 2 13 parts and 25 parts of spinel are placed in a ball milling tank, and then a dispersion medium is added for ball milling. The medium is a mixture of absolute ethanol, isobutanol, paraffin oil and sodium pyrophosphate, and its molar mass ratio is absolute ethanol: isobutanol: paraffin oil: sodium pyrophosphate is 7:5:5:1;

[0032] (2) Add 2 parts of cerium nitrate, 6 parts of sodium oxalate, 6 parts of polyvinyl alcohol, and 2 parts of vinyl triethoxysilane to the powder mixture in step (1) for melting, and do it in an atmosphere protected by nitrogen gas. High-temperature sintering, the temperature of high-temperature sintering is 900°C, the reaction time is 2.3h, and then naturally cooled to room temperature, wherein the inflow rate of nitrogen gas is 0.5L / min, and the pressure in the furnace is kept at 3Mpa;

[0033] (3) Add the reactants in s...

Embodiment 3

[0036] (1) 7 parts of MnO, AlCl 3 3 copies, B 2 o 3 5 parts, Fe 3 o 4 8 parts, ZnO 3 7 copies, Al 2 o 3 5 parts, SiO 2 17 parts and 30 parts of spinel are placed in a ball milling tank, and then a dispersion medium is added for ball milling. The medium is a mixture of absolute ethanol, isobutanol, paraffin oil and sodium pyrophosphate, and its molar mass ratio is absolute ethanol: isobutanol: paraffin oil: sodium pyrophosphate is 7:5:5:1;

[0037] (2) Add 2 parts of cerium nitrate, 7 parts of sodium oxalate, 9 parts of polyvinyl alcohol, and 3 parts of γ-aminopropyltrimethoxysilane to the powder mixture in step (1) for melting, and then melt it in an atmosphere protected by nitrogen gas. Do high-temperature sintering, the temperature of high-temperature sintering is 950°C, the reaction time is 2.7h, and then naturally cool to room temperature, wherein the inflow rate of nitrogen gas is 0.5L / min, and the pressure in the furnace is kept at 4Mpa;

[0038] (3) Add t...

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PUM

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Abstract

The invention discloses a preparation method of a rare earth cerium doped thermistor material. According to the process, rare earth cerium is provided by reaction of cerium nitrate and sodium oxalate,and B value and resistivity of the original thermistor material are changed to a larger extent. The conduction principle of traditional NTC (negative temperature coefficient) thermosensitive ceramicsis the jumping conductance caused by jumping of electrons between different valence-variable ions of the same metal in the position B of a spinel structure, while Mn and Co both have various valenceions, cation distribution of Mn and Co is relatively complex, and various ions such as Mn<4+>, Mn<3+>, Co<3+> and CO<2+> may be present in the position B. Detection shows that after doping of rare earth cerium, the grain size becomes small and the grain boundary increases. In the NTC thermosensitive ceramic material, the grain is a semiconductor, and the grain boundary is a high resistance layer and is the main unit for withstanding voltage. Besides, the thermistor material obtained after doping of rare earth cerium has high stability and good aging resistance, and has greater application prospects in precision instruments such as dialyzers, DNA sequencers, blood analyzers and the like.

Description

technical field [0001] The invention relates to the technical field of resistance materials, in particular to a preparation method of a thermistor material doped with rare earth cerium. Background technique [0002] The negative temperature coefficient (Negative Temperature Coefficient, NTC) thermistor is a material element that is very sensitive to temperature and is made of polycrystalline semiconductor ceramic materials. The resistance value of NTC thermistor will decrease exponentially with the increase of temperature. It has the advantages of temperature sensitivity, low preparation cost and good interchangeability. It is widely used in temperature measurement, temperature control and temperature compensation. At present, most NTC thermistors are composed of 3d transition metal elements, which are composite compounds whose main phase is AB2O4 spinel structure. Take the simplest Mn-Co-O series NTC thermistor as an example, Mn. The electrical properties of the Co 0-seri...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/01C04B35/626
CPCC04B35/01C04B35/62645C04B2235/3217C04B2235/3272C04B2235/3284C04B2235/3409C04B2235/3418C04B2235/443C04B2235/444C04B2235/447C04B2235/483C04B2235/96
Inventor 赵娟赵秋锋
Owner 赵娟
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