Air Moisture Sensing Properties of ZnCr2O4--K2CrO4 Composites

N. KAVASOĞLU and M. BAYHAN

Makale detayları

Air Moisture Sensing Properties of ZnCr2O4--K2CrO4 Composites

Yazarlar:

N. KAVASOĞLU and M. BAYHAN

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Physics 2005 Vol.29 Issue 4, pp.249-256

Belge Tipi:

Makale

Yayın Tarihi:

3/2005

Belge Dili:

Türkçe

Document ID (Org No.):

2000761527

Sıklık:

İki Aylık

eISSN:

1303-6122

pISSN:

1300-0101

Anahtar kelimeler:

Özet:

 

Crystalline structure, surface morphology and the response  to air moisture of ceramic system of composition ZnCr2O4 - KrCrO4  formed by solid state reaction at elevated temperatures were  investigated.  The fired ceramic body, which proved to be mainly  constructed from about 1 m m sized ZnCr2O4 spinel grains, was  found to be porous.  The humidity sensing behaviour of the sensors  reveals that the electrical conduction is protonic and is controlled  through the thin layers of water adsorbed on the surface of the  grains, with charge transfer to the electrodes.  Only the material  containing 20% K2CrO4 in ZnCr2O4 exhibited an exponential  behaviour to humidity, which shows about three orders change in the dc  resistance over the relative humidity (RH) range between 25 and 90%.   Based on ac impedance measurements, an equivalent circuit associated  with a network of RC parallel circuit in series with constant phase  elements (CPEs) has been suggested.  It can be therefore assumed that  such equivalent circuit model of the sensor under moderate moist  condition indicates the charge transport processes mediated by proton  hopping and diffusion.

 

Crystalline structure, surface morphology and the response  to air moisture of ceramic system of composition ZnCr2O4 - KrCrO4  formed by solid state reaction at elevated temperatures were  investigated.  The fired ceramic body, which proved to be mainly  constructed from about 1 m m sized ZnCr2O4 spinel grains, was  found to be porous.  The humidity sensing behaviour of the sensors  reveals that the electrical conduction is protonic and is controlled  through the thin layers of water adsorbed on the surface of the  grains, with charge transfer to the electrodes.  Only the material  containing 20% K2CrO4 in ZnCr2O4 exhibited an exponential  behaviour to humidity, which shows about three orders change in the dc  resistance over the relative humidity (RH) range between 25 and 90%.   Based on ac impedance measurements, an equivalent circuit associated  with a network of RC parallel circuit in series with constant phase  elements (CPEs) has been suggested.  It can be therefore assumed that  such equivalent circuit model of the sensor under moderate moist  condition indicates the charge transport processes mediated by proton  hopping and diffusion.

Makale detayları

Air Moisture Sensing Properties of ZnCr2O4--K2CrO4 Composites

Yazarlar:

N. KAVASOĞLU and M. BAYHAN

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Physics 2005 Vol.29 Issue 4, pp.249-256

Belge Tipi:

Makale

Yayın Tarihi:

3/2005

Belge Dili:

Türkçe

Document ID (Org No.):

2000761527

Sıklık:

İki Aylık

eISSN:

1303-6122

pISSN:

1300-0101

Turk. J. Phys.

29

(2005)

249-256. Full text: pdf Other articles published in the same issue: Turk. J. Phys.

vol.29

iss.4.

Sayı

Makale detayları

Air Moisture Sensing Properties of ZnCr2O4--K2CrO4 Composites

Yazarlar: N. KAVASOĞLU and M. BAYHAN

Yayıncı: TUBITAK

Dergi: Turkish Journal of Physics 2005 Vol.29 Issue 4, pp.249-256

Belge Tipi: Makale

Yayın Tarihi: 3/2005

Belge Dili: Türkçe

Document ID (Org No.): 2000761527

Sıklık: İki Aylık

eISSN: 1303-6122

pISSN: 1300-0101

Turk. J. Phys.

29

(2005)

249-256. Full text: pdf Other articles published in the same issue: Turk. J. Phys.

vol.29

iss.4.

Sayı

Yazarlar:

N. KAVASOĞLU and M. BAYHAN

Yayıncı:

TUBITAK

Dergi:

Turkish Journal of Physics 2005 Vol.29 Issue 4, pp.249-256

Belge Tipi:

Makale

Yayın Tarihi:

3/2005

Belge Dili:

Türkçe

Document ID (Org No.):

2000761527

Sıklık:

İki Aylık

eISSN:

1303-6122

pISSN:

1300-0101