CN101284731A

CN101284731A - Leadless positive temperature coefficient resistance material of high use temperature and stability and method for making same

Info

Publication number: CN101284731A
Application number: CNA2008100377799A
Authority: CN
Inventors: 郑嘹赢; 李国荣; 李艳艳; 冷森林; 王天宝; 曾江涛; 殷庆瑞
Original assignee: Shanghai Institute of Ceramics of CAS
Current assignee: Jiangsu Institute Of Advanced Inorganic Materials
Priority date: 2008-05-21
Filing date: 2008-05-21
Publication date: 2008-10-15
Anticipated expiration: 2028-05-21
Also published as: CN101284731B

Abstract

The invention relates to a resistor material which has high operating temperature, high stability, no lead and positive temperature coefficient, and belongs to the lead-free semiconductor material field. The material has the general formula as follows: (Na0.5Bi0.5)x1(Ba1-x1-x2Lnx2) Ti1-yMyO3+zmol%N, wherein, x1 is larger than 0 and smaller than 0.5, x2 is larger than 0 and smaller than 0.1, y is larger than 0 and smaller than 0.1, z is larger than or equal to 0 and smaller than or equal to 1; Ln is one or more of Sr, Ca, Y and La, M is one or more of Nb, Ta and Sb, and N is one or more of MnO2, Al2O3, SiO2 and TiO2. The high operating temperature and lead-free PTCR material has the advantages that the operating temperature is higher than 130 DEG C, the resistance kicking ratio of the maximum resistance to the minimum resistance is 100:100,000, the resistivity at the room temperature is smaller than 800 ohm.cm, the resistance change rate in the temperature zone ranging from the maximum resistance temperature to the temperature which is 50 DEG C higher than the maximum resistance temperature is smaller than 15 percent, and the total content of lead in ceramic bodies is smaller than 50 ppm. The resistor material can be used for manufacturing various temperature sensors, thermostatic heating elements, current limiters, time delayers, etc., and can be widely applied to the fields of electronic communication, aeronautics and astronautics, automobile industries, household appliances, etc.

Description

High use temperature, the unleaded positive temperature coefficient resistance material of high stable and preparation method thereof

Technical field

The present invention relates to a kind of high stable, the unleaded positive temperature coefficient resistor of high use temperature (PTCR) material and preparation method thereof, belong to lead-free semiconductor material field.

Background technology

The PTCR pottery is a kind of characteristic of semiconductor and ferroelectric stupalith of having concurrently, and promptly crystal grain has characteristic of semiconductor, and the crystal boundary area is low in the following potential barrier of Curie temperature, electronics can free movement, and at Curie temperature (T _c) near form potential barrier when undergoing phase transition, the block electrons electricity is led, and causes resistance that fierce the variation taken place.The temperature profile of PTCR pottery makes the PTCR pottery have unique resistance-temperature (ρ-T) characteristic, current-voltage (I-V) characteristic and electric current-time (I-t) characteristic.

The use temperature of PTCR pottery and its Curie temperature are closely related.The PTCR pottery overwhelming majority of practical application is with BaTiO ₃(T _cBe 120 ℃) ferroelectric material for base, obtain through behind semiconductor (alms giver) and the doping vario-property, and add Pb in right amount the PTCR ceramic performance that is lower than 120 ℃ is tended towards stability.Working temperature is lower than 120 ℃ PTCR pottery can also replace stable performanceization behind the Ba by Sr, although can make T _cDescend, therefore, working temperature is lower than 120 ℃ PTCR pottery and has realized unleaded substantially; And working temperature be higher than 120 ℃ PTCR pottery be by Pb displacement Ba reaching the purpose that Tc rises, thereby the overwhelming majority is plumbiferous.There is PbO volatilization in the leaded PTCR pottery of high use temperature in preparation process, not only cause departing from of stoichiometric ratio in the pottery, makes consistency of product and repeatability reduce, and environment has been caused polluted and destroy.In addition, the treating processes of the waste of lead-containing materials also can cause very big pollution to environment.Therefore, the eco-friendly PTCR material of non-lead base of seeking and develop high use temperature has very positive meaning to reducing environmental pollution.

[Tadashi Shiosaki, et al. Applied Phys.Lett., 87,102104,2005] such as Tadashi Shiosaki of Japan are to [Ba _1-x(Bi _1/2Na _1/2) _x] _1-yLa _yTiO ₃Material is studied, and discovery can make Curie temperature greater than 130 ℃, and the resistance kick is than the lead-free PTCR pottery between 100-10000.China invention ZL200710048275.2 has proposed a kind of unleaded high curie point PTCR thermistor material, and its component is: (Na _1/2Bi _1/2) (Ba _1-x-y+z) TiO ₃+ yM ₁+ zM ₂O+0.02MnO ₂Mol%, the introducing that this material changes element B a, Sr, Ca by the Ba position suppresses the volatilization of BI, thereby reaches the excessive promotion material semiconductor of Ba position and reach the purpose of material production PTC effect.

Although above-mentioned research has obtained to have the PTCR material than low temperature resistance, high electrical resistance kick ratio,, reach maximum value (R at its resistance from its performance _Max, corresponding temperature is designated as T _Max) after, its resistance raises with temperature and descends rapidly, at T _MaxTo T _MaxThe velocity of variation ρ R of+50 ℃ temperature range internal resistance _Max{ resistance of Tmax+50 ℃ of temperature correspondence of note is R _T1, resistance change rate ρ R then _Max=(R _Max-R _T1)/Tmax} is generally greater than 50%.In a single day because voltage fluctuation causes temperature slightly to rise, will lose original temperature, current balance type greatly owing to the material heating power becomes, thereby material temperature, electric current are further risen in actual applications, vicious cycle finally causes control fails.The present invention reduces room temperature resistivity, improves resistance kick ratio by not only can realizing the semiconductor of material in the interpolation of Ti position, and has improved material greatly at T _MaxTo T _MaxThe temperature stability of+50 ℃ of temperature ranges can improve the stability and the reliability of unleaded high use temperature PTCR device greatly.

Summary of the invention

The object of the present invention is to provide a kind of high use temperature, the unleaded positive temperature coefficient resistor of high stable (PTCR) material, can be used for making all kinds of temperature sensors, constant temperature heating element, restrictor, time delay unit etc., be widely used in fields such as telecommunications, aerospace, automotive industry, household electrical appliance.

The composition general formula of high use temperature of the present invention, high stable lead-free PTCR material is

(Na _0.5Bi _0.5) _x1(Ba _1-x1-x2Ln _x2)Ti _1-yM _yO ₃+zmol％N。

0＜x1＜0.5 wherein; 0＜x2＜0.1; 0＜y＜0.1; 0＜z≤1; Ln is one or more among Sr, Ca, Y, the La; M is one or more of Nb, Ta, Sb; N is MnO ₂, Al ₂O ₃, SiO ₂, TiO ₂One or more.

Wherein, preferred z value is 0.05＜z≤1, and preferred x1 value is 0.01＜x1＜0.5, and preferred x2 value is 0.01＜x1＜0.08, and preferred y value is 0.01＜y＜0.08.

Ln mixes Ba position (A position) as high valence ion, can promote the semiconductor of material, reduces the normal temperature resistance of material, and this generally adopts in general lead-free PTCR pottery preparation.Unique distinction of the present invention is the position by another high valence ion M displacement Ti, has both played the effect that promotes semiconductor, can reduce material simultaneously greatly at T _MaxTo T _MaxThe resistance change rate ρ R of+50 ℃ of temperature ranges _MaxThis is because after replace at high price the Ba position of routine at present, because the materials A position is contained Na, Bi, three kinds of ions of Ba simultaneously, although therefore mix and can make material generation semiconductor in the A position, but after doping, may produce a certain amount of free Na ion, at normal temperatures, because the grain boundary defects gradient forms the obstruction of potential barrier, be difficult to migration, more than Curie temperature, this ion is easy to take place migration and causes conductivity of electrolyte materials and stability decreases.And the defective that the displacement by the Ti position forms can suppress the A position and produces dissociated ion, especially Na ion in semiconductor.Additive N effect in the present invention mainly is to purify crystal boundary, thereby further reduces the resistivity at room temperature of material.

The concrete preparation method of stupalith of the present invention comprises batching, synthetic, sintering, comprises the steps:

(1) batching: adopted TiO ₂, CaCO ₃, SrCO ₃, BaCO ₃, Na ₂CO ₃, Bi ₂O ₃, Y ₂O ₃, La ₂O ₃, Nb ₂O ₅, Ta ₂O ₅, Sb ₂O ₅, MnCO ₃, Al ₂O ₃, SiO ₂Deng being raw material, (Na _0.5Bi _0.5) _X1(Ba _1-x1-x2Ln _X2) Ti _1-yM _yO ₃The stoichiometry weighing of+zmol%N, wherein 0＜x1＜0.5; 0＜x2＜0.1; 0＜y＜0.1; 0＜z≤1.

Above-mentioned preferred z value is 0.05＜z≤1, and preferred x1 value is 0.01＜x1＜0.5, and preferred x2 value is 0.01＜x1＜0.08, and preferred y value is 0.01＜y＜0.08.

(2) synthetic: as medium, ball milling mixes with deionized water, oven dry back briquetting.Be placed on the ceramic plate and synthesize in advance under 120-360 minute the condition of 800-1000 ℃ of insulation, after pulverizing then, sieving, fine grinding, oven dry, adding additives, moulding, plastic removal (insulation is more than 120 minutes more than 400 ℃).

(3) sintering: sintering temperature is 1200～1350 ℃, is incubated 1-5 hour, naturally cooling.

With the base sheet behind the sintering through cold working, ultrasonic cleaning, go up Ohm contact electrode, operational PTCR ceramic component.

High use temperature of the present invention, lead-free PTCR material use temperature are higher than 130 ℃, the resistance kick is than (maximum resistance and minimum resistance ratio): 100-100000, resistivity at room temperature is less than 800 Ω .cm, in the temperature that reaches maximum resistance to the temperature range internal resistance rate of descent ρ R that is higher than 50 ℃ of this top temperatures _MaxLess than 15%, the overall lead content of porcelain body is less than 50ppm.This shows special-effect of the present invention.

Description of drawings

Fig. 1 is the resistivity-temperature characteristic curve of the PTCR material in the embodiment of the invention 1

Embodiment

Further specify content of the present invention below by embodiment, apparent, embodiment only illustrates goal of the invention, limits the present invention absolutely not.

Embodiment 1:

Get x=0.2, Ln is La, and x2=0.05, M are Nb, y=0.05, and z=0 then forms molecular formula and is (Na _0.5Bi _0.5) _0.2(Ba _0.75La _0.05) Ti _0.95Nb _0.05O ₃Pottery form.The TiO that adopts impurity lead content to be strictly controlled ₂, BaCO ₃, Na ₂CO ₃, Bi ₂O ₃, La ₂O ₃, Nb ₂O ₅Be raw material, by 1350 ℃/2 hours air atmosphere sintering, cold working, ultrasonic cleaning, go up Ohm contact electrode, operational PTCR ceramic component.Its resistance-temperature characteristic is seen Fig. 1, and specific performance is listed in table 1.

Embodiment 2-16:

The room temperature resistivity, Curie temperature, resistance kick of regulating material by the variation that changes different displacement compositions and additive than and the resistance change rate ρ R in 50 ℃ of temperature ranges more than the Curie temperature _MaxAdopted TiO ₂, CaCO ₃, SrCO ₃, BaCO ₃, Na ₂CO ₃, Bi ₂O ₃, Y ₂O ₃, La ₂O ₃, Nb ₂O ₅, Ta ₂O ₅, Sb ₂O ₅, MnCO ₃, Al ₂O ₃, SiO ₂, etc. be raw material, press chemical constitution listed in the table 1, press chemical formula (Na _0.5Bi _0.5) _X1(Ba _1-x1-x2Ln _X2) Ti _1-yM _yO ₃The stoichiometry weighing of+zmol%N.Other processing condition are with embodiment 1, and its performance is listed in table 1.

The composition of table 1 embodiment 1-16 and performance table

Claims

1, high use temperature, the unleaded positive temperature coefficient resistance material of high stable is characterized in that chemical formula is

(Na _0.5Bi _0.5) _x1(Ba _1-x1-x2Ln _x2)Ti _1-yM _yO ₃+zmol％N；

0＜x1＜0.5 wherein; 0＜x2＜0.1; 0＜y＜0.1; 0＜z≤1;

Wherein Ln is one or more among Sr, Ca, Y, the La; M is one or more of Nb, Ta, Sb; N is MnO ₂, Al ₂O ₃, SiO ₂, TiO ₂One or more.

2, by the described high use temperature of claim 1, the unleaded positive temperature coefficient resistance material of high stable, it is characterized in that described z value is 0.05＜z≤1.

3, press claim 1 or 2 described high use temperatures, the unleaded positive temperature coefficient resistance material of high stable, it is characterized in that described x1 value is 0.01＜x1＜0.5, the x2 value is 0.01＜x1＜0.08.

4, press claim 1 or 2 described high use temperatures, the unleaded positive temperature coefficient resistance material of high stable, it is characterized in that described y value is 0.01＜y＜0.08.

5, the preparation method of high use temperature, the unleaded positive temperature coefficient resistance material of high stable comprises batching, mixing, briquetting, synthesizes in advance, pulverizes, sieves, oven dry, moulding, plastic removal, sintering, it is characterized in that:

The raw material of batching is TiO ₂, CaCO ₃, SrCO ₃, BaCO ₃, Na ₂CO ₃, Bi ₂O ₃, Y ₂O ₃, La ₂O ₃, Nb ₂O ₅, Ta ₂O ₅, Sb ₂O ₅, MnCO ₃, Al ₂O ₃, SiO ₂, press stoichiometric equation (Na _0.5Bi _0.5) _X1(Ba _1-x1-x2Ln _X2) Ti _1-yM _yO ₃+ zmol%N weighing, wherein 0＜x1＜0.5; 0＜x2＜0.1; 0＜y＜0.1; 0＜z≤1;

Pre-synthesis condition is 800-1000 ℃ of insulation 120-360 minute;

Sintering condition is 1200～1350 ℃ of insulations 1-5 hour.

6, by the preparation method of the described high use temperature of claim 5, the unleaded positive temperature coefficient resistance material of high stable, it is characterized in that the z value is 0.05＜z≤1.

7, press the preparation method of claim 5 or 6 described high use temperatures, the unleaded positive temperature coefficient resistance material of high stable, it is characterized in that the x1 value is 0.01＜x1＜0.5, the x2 value is 0.01＜x1＜0.08.

8, press the preparation method of claim 5 or 6 described high use temperatures, the unleaded positive temperature coefficient resistance material of high stable, it is characterized in that the y value is 0.01＜y＜0.08.