Wiendartun 1), Dani Gustaman Syarif 2), Nur Asiah Jamil 1)

Transcription

1 APS, ITB, -33 July 009 Electrical Characteristics of Cu Added-ZnFe Ceramic Semiconductor in Air and Ethanol Gas Atmosphere Wiendartun 1), Dani Gustaman Syarif ), Nur Asiah Jamil 1) 1) Department of Physics, UPI, Bandung, ) Nuclear Technology Center for Materials and Radiometry BATAN, Bandung. danigusta@yahoo.com

2 INTRDUCTIN In modern life people need many sophisticated products for daily life such as food industry, environment and health, one of the products required is gas sensor. It is necessary to get capability in self producing gas sensor by utilizing mineral containing Zn and Fe abundant in Indonesia. ZnFe based-thick film ceramic for ethanol gas sensor with low working temperature. A preliminary study of producing thick film ceramic based on ZnFe for ethanol gas sensor. Theoretically, the addition of Cu may change the microstructure of the ZnFe, so the ZnFe thick film ceramic with different microstructure may have different electrical characteristics, then may change the electrical characteristics of the ZnFe thick film ceramic. The aim of this work is to know the effect of Cu addition on electrical characteristics of the ZnFe thick film ceramics in air and ethanol gas.

3 EXPERIMENT : Zn, Fe 3, Cu ( 0 and 10 mole %) rganic vehicle (V) Mixing Glass Frit ( 5%) Paste Characterization: 1. Electrical (Air and Ethanol gas atmosphere). XRD 3. Microstructural (SEM) Screen Printing Thick Film Ceramics Green film ceramics Firing Flow diagram of the experiment procedure APS - ITB, -33 July 009

4 ZnFe based-thick film ceramic Alumina substrate Electrodes of Ag coating A schematic view of a thick film ceramic sensor

5 Appearance of the ZnFe thick film ceramic before cutting. Thick film ceramic Silver electrode

6 Schematic figure of electrical characterization. hmmeter Silver electrode Chamber Thermocouple Temperature controller Substrate Heater Thick film sensor layer Ethanol source

7 RESULT (XRD) Diffraction profile of ZnFe thick film. Diffraction profile of Cu added-znfe thick film. C is peak from Cu. A is from substrate. XRD profile of ZnFe based-thick film

8 RESULT (XRD) Lattice constant of ZnFe and Cu added- ZnFe thick film ceramics. No. Concentration of Cu (%) Lattice constant (Angstrom) ± ± 0.018

9 RESULTS (Microstructure) Microstructure of ZnFe thick film. Microstructure of ZnFe :Cu 10 mole % thick film. Microstructure of the ZnFe thick film

10 RESULTS (Electrical Characteristics), ,5 3.0 ln R(Mohm) 3,0,5 di udara 01ppm,0 507ppm 516ppm 1,5 619ppm 77ppm 1,0 ln R (Mohm) di udara ppm 531ppm 51ppm 68ppm 809ppm 0,0015 0,0016 0,0017 0,0018 0,0019 0,000 0,001 0,00 1/T(K) /T(K) ln R versus 1/T for ZnFe thick film ceramic in air and ethanol gas. ln R versus 1/T for Cu added- ZnFe thick film ceramic in air and ethanol gas.

11 RESULTS (Electrical Characteristics) Resistance (R) as a function of ethanol gas concentration of ZnFe thick film ceramic for measurement temperature of 90oC and of Cu added-znfe thick film ceramic for measurement temperature of 10oC.

12 CNCLUSINS Thick film ceramics of ZnFe and Cu added-znfe had been well produced at firing temperature of 1000 o C. All of the thick films crystallizes in spinel cubic. The addition of 10 mole % Cu : decreases the electrical resistance, decreases the working temperature and decreases the sensitivity of the ZnFe thick film ceramic, because the addition of 10 mole % Cu changes the microstructure resulting in large grains. The produced thick film ceramics have semiconductor characteristic where the resistance decreases with the increase of temperature. The resistance of the films measured in ethanol gas is lower than that of the film measured in air. The resistance of the film decreases with the increase of ethanol gas concentration.

13 THANK YU ACKNWLEGMENT The authors wish to acknowledge their deep gratitude to DIKTI, Department of National Education of Indonesian Government for financial support under HIBAH BERSAING program with contract No.01/SPH/PP/DPM/III/ M/III/008