isc, unpad 30 - Direktori File UPI

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ISC, UNPAD 30

ISC, UNPAD 30--31 Oct 200831 Oct 2008

Synthesis and Characterization

Synthesis and Characterization of of CuFe CuFe

₂₂

O O

₄₄

Thick Film Ceramics for NTC

Thick Film Ceramics for NTC Thermistor Thermistor Using

Using Yarosite Yarosite as Raw Material as Raw Material

Wiendartun

¹¹

)), Dani Gustaman Syarif , Dani Gustaman Syarif

²²

) )

11)) Department of Physics, UPI, BandungDepartment of Physics, UPI, Bandung

22 )Nuclear Technology Center for Materials and Radiometry )Nuclear Technology Center for Materials and Radiometry ––

BATAN, Bandung.

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INTRODUCTION INTRODUCTION

R vs T- THERMISTOR

THERMISTOR Thermally Sensitive Resistor.

NTC CHARACTERISTIC PRODUCT EXAMPLES APPLICATIONS

Current limiter thermistor

Specialize Thermistor

Incubator

Computer

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INTRODUCTION

(Continuation)(Continuation) Important

Important electronicelectronic componentcomponent..

-- SectorsSectors:: Biomedical,Biomedical, aerospace,aerospace, instrumentation,instrumentation, communications,

communications, automotiveautomotive andand HVACRHVACR (Heating,(Heating, Ventilation,

Ventilation, AirAir conditioningconditioning andand Refrigeration)Refrigeration)..

--ApplicationApplication :: TemperatureTemperature sensorsensor measurement,measurement, currentcurrent limiter,

limiter, circuitcircuit compensation,compensation, suppressionsuppression ofof inin rushrush-- current,

current, flowflow raterate sensorsensor andand pressurepressure sensorsensor..

It

It isis necessarynecessary toto getget capabilitycapability inin selfself producingproducing thermistor

thermistor byby utilizingutilizing materialmaterial abundantabundant inin IndonesiaIndonesia suchsuch us

us yarositeyarosite mineralmineral ((FeFe₂₂OO₃₃))  CuFeCuFe₂₂OO₄₄ basedbased--thickthick filmfilm forfor NTC

NTC ThermistorThermistor..

The

The thermistorthermistor inin thethe formform ofof thickthick filmfilm isis possiblepossible forfor miniaturization

miniaturization andand integrationintegration .. AdvantagesAdvantages :: moremore practical,

practical, profitableprofitable economically,economically, needneed aa fewfew material,material, andand fired

fired atat lawlaw temperaturetemperature..

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YAROSITE MNERAL YAROSITE MNERAL

Hibah BERSAING, 13 Oktober 2008 Hibah BERSAING, 13 Oktober 2008

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EXPERIMENT : EXPERIMENT :

Crushing Sieving

Mixing

Powder of Fe₂O₃ (derived from yarosite mineral) and CuO

Glass Frit Organic vehicle

Paste

ISC

ISC -- UNPAD, 30UNPAD, 30--31 Oct 200831 Oct 2008 Mixing

Characterization:

1. Electrical 2. XRD

3. Microstructural (SEM)

Paste

Screen Printing

Firing ( 900 - 1100 C)

Thick Film Ceramics Electroding

Fabrication of CuFe₂O₄ thick film ceramics from yarosite mineral

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SCREEN PRINTING SCREEN PRINTING

Squeeze

“Screen”

“screen” stress

Hibah BERSAING, 13 Oktober 2008 Hibah BERSAING, 13 Oktober 2008

“snap-off”

distance

Substrate

Coated Film

Paste

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Electrical Characteristic Electrical Characteristic

R = R

₀₀

. Exp.(B/T) . Exp.(B/T) Ln

Ln R = B/T + R = B/T + Ln Ln Ro Ro Ea =

Ea = B.k B.k α =

α = -- B/T B/T

²²

R

R = = ThermistorThermistor resistanceresistance R

R_oo = Resistance at the infinite temperature= Resistance at the infinite temperature BB = = ThermistorThermistor constantconstant

TT = Temperature of = Temperature of thermistorthermistor in Kelvinin Kelvin Ea = Activation energy

Ea = Activation energy

KK = The Boltzmann constant= The Boltzmann constant ΑΑ = Sensitivity of = Sensitivity of thermistorthermistor

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RESULT : RESULT :

Chemical composition of Fe

₂₂

O O

₃₃

powder powder derived from

derived from yarosite yarosite table table

No. Component Concentration

(Weight %)

1 Fe₂O₃ 93.80

2 Al₂O₃ 2.54

3 SiO₂ 1.15

4 TiO₂ 1.02

5 MgO 0.19

6 K₂O 0.12

7 CaO 0.59

8 Na₂O 0.50

9 MnO 0.09

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RESULT RESULT Thick Film (

Thick Film ( yarosite yarosite))

Visual appearance Visual appearance

ISC

ISC --UNPAD, 30UNPAD, 30--31 31 OktoberOktober 20082008 Alumina

Alumina SubstratSubstrat Thick film before fired Thick film fired at 1100 C/1 hrThick film before fired Thick film fired at 1100 C/1 hr

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A typical thick film

A typical thick film thermistor thermistor

Sensor Layer

Silver Electrodes

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RESULT (XRD) RESULT (XRD)

Fired at 900 ^oC

XRD profile of CuFe₂O₄ based-thick film

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RESULTS (Microstructure) RESULTS (Microstructure)

Microstructure of the CuFe₂O₄ thick film

Fired at 900 ^oC Fired at 1000 ^oC

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RESULTS RESULTS

(Electrical Characteristics) (Electrical Characteristics)

3 3.5 4 4.5

ln R(Mohm)

Ln resistivity () vs 1/T of CuFe

₂

O

₄

thick film ceramics.

0 0.5 1 1.5 2 2.5

0.0025 0.0027 0.0029 0.0031 0.0033 0.0035 1/T(1/K)

ln R(Mohm)

900^oC

▲ 1000^oC

□ 1100^oC

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RESULTS RESULTS

(Electrical Characteristics) (Electrical Characteristics)

Table of electrical characteristics of CuFe₂O₄ thick film ceramics.

No. Firing Temperature

(^oC)

B (^oK)

 (%/^oK)

R_RT (M.Ohm)

Ea (eV)

Market requirement for : B is ≥ 2000 ^oK

 is ≥ 2.2 %/^oK[7]

 _RT = 10 ohm.cm -1 Mohm.cm [4].

(^oC) 1.

2.

3.

900 1000 1100

4857 3027 3596

5.4 3.4 4.0

125.6 7.8 37.6

0.42 0.26 0.31

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CONCLUSIONS CONCLUSIONS

CuFe

CuFe₂₂OO₄₄ thickthick filmfilm ceramicsceramics utilizingutilizing FeFe₂₂OO₃₃ derivedderived fromfrom yarosite

yarosite mineralmineral havehave beenbeen wellwell preparedprepared atat 900900^ooC,C, 10001000^ooCC and

and 11001100^ooCC..

All

All ofof thethe thickthick filmsfilms crystallizecrystallize inin tetragonaltetragonal spinelspinel..

The

The increaseincrease ofof firingfiring temperaturetemperature tilltill 10001000^ooCC decreasesdecreases thethe resistance

resistance andand thermistorthermistor constantconstant ofof thethe thickthick films,films, however,

however, aa furtherfurther increaseincrease toto 11001100^ooCC increasesincreases thethe however,

however, aa furtherfurther increaseincrease toto 11001100^ooCC increasesincreases thethe resistance

resistance andand thermistorthermistor constantconstant ofof themthem..

So,

So, 10001000^ooCC isis thethe optimumoptimum firingfiring temperaturetemperature forfor preparingpreparing the

the thickthick filmsfilms inin thisthis workwork..

The

The thickthick filmfilm firedfired atat 10001000^ooCC hashas optimaloptimal characteristiccharacteristic namely

namely thermistorthermistor constantconstant (B)(B) == 31503150KK andand roomroom temperature

temperature resistanceresistance (R(R_RT_RT)) == 77..99 MOhmMOhm.. TheseThese valuesvalues fitfit the

the marketmarket requirementrequirement forfor NTCNTC thermistorthermistor..

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THANK YOU THANK YOU

ACKNOWLEGMENT ACKNOWLEGMENT The

The authorsauthors wishwish toto acknowledgeacknowledge theirtheir deepdeep gratitudegratitude to

to DIKTI,DIKTI, DepartmentDepartment ofof NationalNational EducationEducation ofof Indonesian

Indonesian GovernmentGovernment forfor financialfinancial supportsupport underunder HIBAH

HIBAH BERSAINGBERSAING programprogram withwith contractcontract HIBAH

HIBAH BERSAINGBERSAING programprogram withwith contractcontract No

No..014014/SP/SP22H/PP/DPH/PP/DP22M/III/M/III/20082008

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