Author(s): Nobre Marcos A. de Lima | Lanfredi Silvania
Journal: Materials Research
ISSN 1516-1439
Volume: 6;
Issue: 2;
Start page: 151;
Date: 2003;
Original page
Keywords: varistor | spinel | semiconductor | impedance spectroscopy
ABSTRACT
Impedance spectroscopy technique was used to investigate the electric properties of Zn7Sb2O12, an electroceramic with inverse spinel type structure. The electric characterization of the Zn7Sb2O12 semiconducting ceramic was performed at temperature from 250 to 550 degreesC, in the frequency range from 5 Hz to 13 MHz. Zinc antimoniate phase was synthesized by the polymeric precursors method. The bulk resistance curve as a function of temperature exhibits a thermistor behavior with negative temperature coefficient. The bulk conductivity follows the Arrhenius law with two linear branches of different slopes positioned at around a region of transition, 450 degreesC > T > 350 degreesC. The activation energy values at low temperature (< 350 degreesC) and high temperature (> 450 degreesC) are equals to 0.78 and 0.61 eV, respectively. The existence of a phase transition limiting these regions is discussed.
Journal: Materials Research
ISSN 1516-1439
Volume: 6;
Issue: 2;
Start page: 151;
Date: 2003;
Original page
Keywords: varistor | spinel | semiconductor | impedance spectroscopy
ABSTRACT
Impedance spectroscopy technique was used to investigate the electric properties of Zn7Sb2O12, an electroceramic with inverse spinel type structure. The electric characterization of the Zn7Sb2O12 semiconducting ceramic was performed at temperature from 250 to 550 degreesC, in the frequency range from 5 Hz to 13 MHz. Zinc antimoniate phase was synthesized by the polymeric precursors method. The bulk resistance curve as a function of temperature exhibits a thermistor behavior with negative temperature coefficient. The bulk conductivity follows the Arrhenius law with two linear branches of different slopes positioned at around a region of transition, 450 degreesC > T > 350 degreesC. The activation energy values at low temperature (< 350 degreesC) and high temperature (> 450 degreesC) are equals to 0.78 and 0.61 eV, respectively. The existence of a phase transition limiting these regions is discussed.
