The Effect Of SiOThe Effect Of SiO22 Addition On The Characteristics Of Addition On The Characteristics Of CuFe2O4 Ceramics For NTC Ceramics For NTC ThermistorThermistor

Wiendartun1) & Dani Gustaman Syarif2)

1) Departement Of Physics, UPI, Bandung.2) Nuclear Technology Center for Materials and Radiometry – BATAN, Bandung.

INTRODUCTIONTHERMISTORTHERMISTOR ThermallyThermally SensitiveSensitive ResistorResistor..NTC CHARACTERISTIC : NTC CHARACTERISTIC :

PRODUCT EXAMPLES:PRODUCT EXAMPLES:

ImportantImportant electronicelectronic componentcomponent..-- SectorsSectors:: Biomedical,Biomedical, aerospace,aerospace, instrumentation,instrumentation, communications,communications, automotiveautomotive

RESULT (XRD)

RESULTS (Microstructure)

RESULTS (Electrical Characteristics)

0.25 w/o SiO2

0

50

100

150

200

250

300

350

15 25 35 45 55 65 75

2q (Derajat)

Inte

nsit

as (

Cp

s)

101 202 220

303

224 413404

112

211

312

0.50 w/o SiO2

2q (Derajat)

Inte

nsit

as (

a.u

.)

0 w/o SiO2

0.75 % SiO2

0

50

100

150

200

250

15 25 35 45 55 65 75

2q (Derajat)

Inte

ns

ita

s (

Cp

s)

101112/200

211

103

202220

312

303224

413 404

XRD profiles of CuFe2O4 based-ceramics

0.25 w/o SiO2

Microstructure of the CuFe2O4 based-ceramics

0 w/o SiO2

Grain boundary material

Grain

Pore

59m

0.75 w/o SiO2

Grain boundary material

Pore

59m

Grain

-- SectorsSectors:: Biomedical,Biomedical, aerospace,aerospace, instrumentation,instrumentation, communications,communications, automotiveautomotiveandand HVACRHVACR (Heating,(Heating, Ventilation,Ventilation, AirAir conditioningconditioning andand Refrigeration)Refrigeration)..-- ApplicationApplication :: TemperatureTemperature measurement,measurement, circuitcircuit compensation,compensation, suppressionsuppression ofof

inin rushrush--current,current, flowflow raterate sensorsensor andand pressurepressure sensorsensor..Most,Most, thermistorsthermistors areare producedproduced fromfrom spinelspinel ceramicsceramics basedbased onon transitiontransition metalmetaloxidesoxides formingforming generalgeneral formulaformula ABAB22OO44..NeedNeed alternativealternative (Expecially(Expecially basedbased onon abundantabundant materialmaterial (mineral)(mineral) inin Indonesia)Indonesia) CuFeCuFe22OO44 isis proposed,proposed, includingincluding thatthat addedadded withwith SiOSiO22..PredictedPredicted thatthat thethe SiOSiO22 additionaddition cancan improveimprove thethe characteristicscharacteristics ofof thethe CuFeCuFe22OO44

ceramicceramic forfor NTCNTC thermistorsthermistors

EXPERIMENT

RESULTS (Electrical Characteristics)

CONCLUSIONSTheThe CuFeCuFe22OO44 ceramicsceramics cancan bebe appliedapplied asas NTCNTC ThermistorThermistor..TheThe graingrain sizesize ofof thethe CuFeCuFe22OO44 ceramicsceramics tendstends toto decreasedecrease bybyadditionaddition ofof SiOSiO22..TheThe additionaddition ofof SiOSiO22 increasesincreases thethe roomroom temperaturetemperatureresistivityresistivity ((RT)RT) andand thethe thermistorthermistor constantconstant (B)(B) ofof thetheCuFeCuFe22OO44 ceramicsceramics duedue toto thethe segregatedsegregated SiOSiO22..TheThe valuevalue ofof ((RT)RT) andand (B)(B) ofof thethe CuFeCuFe22OO44 ceramicsceramics mademade ininthisthis workwork fitsfits thethe marketmarket requirementrequirement..

REFERENSIBetaTHERM Sensors [on line]. Available: http://www.betatherm.com.Eun Sang Na, Un Gyu paik, Sung Churl Choi, “The effect of a sintered microstructure on the electrical properties of a Mn-Co-Ni-O thermistor”, Journal of Ceramic Processing Research, Vol.2, No. 1, pp 31-34, 2001.Wiendartun, Dani Gustaman Syarif. The Effect of TiO2 Addition on the Characteristics of Sciences (ICMNS) 2006, ITB, Bandung, October 2006.

ACKNOWLEGMENTACKNOWLEGMENTTheThe authorsauthors wishwish toto acknowledgeacknowledge theirtheir deepdeep gratitudegratitude toto DIKTI,DIKTI, DepartmentDepartment ofofNationalNational EducationEducation ofof IndonesianIndonesian GovernmentGovernment forfor financialfinancial supportsupport underunderhibahhibah PekertiPekerti programprogram withwith contractcontract NoNo..014014/SPP/PP/DP/SPP/PP/DP22M/II/M/II/20062006aa

CuO Fe3O4 SiO2

MIXING

CALCINATION

CRUSHING

800 °C/2 h

PRESSINGCHARACTERIZATION XRD Electrical Microstructural

3, 9 ton/Cm2

SINTERING1100 ºC/2 h

Sintering Furnace Optical Microscope

XRD

Ln resistivity () vs 1/T of SiO2added- CuFe2O4 ceramics

2

3

4

5

6

7

8

9

10

0.0025 0.003 0.0035

1/T (1/oK)

ln R

esis

tivity

list

rik, r

(ln

Ohm

-cm

)

0 w/o SiO2

0.25 w/o SiO2

0.50 w/o SiO2

0.75 w/o SiO2

No.No. Additive of TiOAdditive of TiO22

(w/o)(w/o)BB

(( K)K)αα

(%/(%/ K)K)

ρRT ρRT (Ohm(Ohm--Cm)Cm)

1.1. 0.000.00 25482548 2.832.83 291291

2.2. 0.250.25 23582358 2.622.62 10791079

3.3. 0.500.50 28842884 3.203.20 47884788

4.4. 0.750.75 33083308 3.683.68 94009400

Market requirement for B ≥ 2000 oK and ≥ 2.2 %/oKMarket requirement for RT = 10 ohm.cm -1 Mohm.cm