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Double-layer NTC (negative temperature coefficient) thermistor and preparation method thereof

A negative temperature coefficient, thermistor technology, applied in the direction of resistors with negative temperature coefficient, resistance manufacturing, resistors, etc., can solve the problems of small resistivity and many restrictions, achieve good stability, reduce costs, The experimental process is simple and efficient

Inactive Publication Date: 2017-08-18
XINJIANG TECHN INST OF PHYSICS & CHEM CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] After searching Chinese patent CN 104124014 A discloses, adopts a x mn 3-x o 4 (A is one or more of Zn, Ni, Co, Fe) and LaSr y BO 3 (B is one or more of Fe, Co, Ni, Mn) double-layer negative temperature coefficient (NTC) thermistor, the resistivity range is 10-10 4 Ω·cm, the resistivity is too small, so it can only be used in the environment with a temperature below 300°C, and its double-layer structure is a double-layer film prepared by casting, which has many restrictions on raw materials, and not all materials can be compared Prepared well as a slurry and then a bilayer film

Method used

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  • Double-layer NTC (negative temperature coefficient) thermistor and preparation method thereof

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Experimental program
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Embodiment 1

[0016] a.MgAl 2 o 4 Preparation of powder: weigh 14.3339g analytically pure Al 2 o 3 Mix with 5.6661g of analytically pure MgO, place in an agate mortar and grind for 6 hours to obtain oxide powder, calcinate the oxide powder at a temperature of 1100°C for 1.5 hours, and grind the calcined powder for 8 hours to obtain MgAl 2 o 4 Powder;

[0017] b. LaCrO 3 Preparation of powder: weigh 20.3920g of analytically pure La 2 o 3 and 9.6080g of analytically pure Cr 2 o 3 Mix and grind in an agate mortar for 6 hours to obtain oxide powder. Calcinate the oxide powder at 1000°C for 1.5 hours, and then grind the calcined powder for 8 hours to obtain LaCrO 3 Powder;

[0018] c. Preparation of double-layer negative temperature coefficient thermistor: weigh 0.498gMgAl obtained in step a respectively 2 o 4 Powder, the 0.359gLaCrO obtained in step b 3 powder, first LaCrO 3 Pour the powder into the Ф10mm molding mold, shake well and then pour MgAl 2 o 4 Powder, at 30Kg / cm 2 Th...

Embodiment 2

[0022] a.MgAl 2 o 4 Preparation of powder: weigh 14.3339g analytically pure Al 2 o 3 Mix with 5.6661g of analytically pure MgO, place in an agate mortar and grind for 8 hours to obtain oxide powder, calcinate the oxide powder at a temperature of 1000°C for 2 hours, and grind the calcined powder for 8 hours to obtain MgAl 2 o 4 Powder;

[0023] b. LaCrO 3 Preparation of powder: weigh 20.3920g of analytically pure La 2 o 3 and 9.6080g of analytically pure Cr 2 o 3 Mix and grind for 8 hours in an agate mortar to obtain oxide powder. Calcinate the oxide powder at a temperature of 1300°C for 4 hours, and then grind the calcined powder for 8 hours to obtain LaCrO 3 Powder;

[0024] c. Preparation of double-layer NTC thermistor: Weigh 0.8gMgAl obtained in step a respectively 2 o 4 Powder, the 1.6gLaCrO obtained in step b 3 powder, first LaCrO 3 Pour the powder into the graphite mold matched with the vacuum hot-press furnace, shake it well and pour it into MgAl 2 o 4 T...

Embodiment 3

[0028] a.MgAl 2 o 4 Preparation of powder: weigh 14.3339g analytically pure Al 2 o 3 Mix with 5.6661g of analytically pure MgO, place in an agate mortar and grind for 10 hours to obtain oxide powder, calcinate the oxide powder at 1300°C for 4 hours, and grind the calcined powder for 8 hours to obtain MgAl 2 o 4 Powder;

[0029] b. LaCrO 3 Preparation of powder: weigh 20.3920g of analytically pure La 2 o 3 and 9.6080g of analytically pure Cr 2 o 3 Mix and grind in an agate mortar for 10 hours to obtain oxide powder. Calcinate the oxide powder at 1300°C for 2 hours, and then grind the calcined powder for 8 hours to obtain LaCrO 3 Powder;

[0030] c. Preparation of double-layer NTC thermistor: Weigh 0.1gMgAl obtained in step a respectively 2 o 4 Powder, 0.6gLaCrO obtained in step b 3 powder, first LaCrO 3 Pour the powder into the Ф10mm molding mold, shake well and then pour MgAl 2 o 4 Powder, at 60Kg / cm 2 The pressure is used for briquetting, and the holding time...

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Abstract

The invention relates to a double-layer NTC (negative temperature coefficient) thermistor and a preparation method thereof. The resistor is of a double-layer structure formed by a MgAl2O4 layer A and a LaCrO3 layer B, a double-layer structure formed by a dopant Mg(1-x)MxAl2O4 of the MgAl2O4 layer A and the LaCrO3 layer B, a double-layer structure formed by the MgAl2O4 layer A and a dopant La(1-x)MxCrO3 of the LaCrO3 layer B, or a double-layer structure formed by the dopant Mg(1-x)MxAl2O4 of the MgAl2O4 layer A and the dopant La(1-x)MxCrO3 of the LaCrO3 layer B. Tests prove that the electrical resistivity range of the double-layer NTC thermistor is 342-5.5*10<8> omega.cm, and a mole number ratio A / B of the A layer to the B layer is 0.28-2.33. Compared with the prior art, the prepared double-layer NTC thermistor is wide in working range, can be suitable for the room temperature being 1,000 DEG C and has stable electrical performance at the high temperature, and the preparation process is simple and efficient.

Description

technical field [0001] The invention relates to the technical field of negative temperature coefficient (NTC) thermistors, in particular to a double-layer NTC thermistor capable of working from room temperature to 1000°C and a preparation method thereof. Background technique [0002] Research on negative temperature coefficient (NTC) thermistors is divided into low temperature (≤-60°C); medium temperature (-60°C—300°C) and high temperature (≥300°C). High-temperature NTC thermistors have irreplaceable applications in the fields of space, automobile exhaust gas temperature measurement, and industrial equipment temperature measurement and control. However, NTC thermistors in high-temperature working environments are prone to unstable electrical properties, that is, the resistance drift rate is too large, which affects the application of NTC thermistors in actual research and production. Therefore, it is important to obtain NTC materials with good performance and stability at h...

Claims

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Application Information

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IPC IPC(8): C04B35/44C04B35/50C04B35/12C04B35/626C04B41/88H01C7/04H01C17/30
CPCC04B35/12C04B35/44C04B35/50C04B35/62605C04B41/009C04B41/5122C04B41/88C04B2235/3206C04B2235/96H01C7/043H01C17/30C04B41/4539C04B41/52
Inventor 赵青印杏莲张博常爱民
Owner XINJIANG TECHN INST OF PHYSICS & CHEM CHINESE ACAD OF SCI