Grain boundary electric characterization of Zn7Sb2O12 semiconducting ceramic: A negative temperature coefficient thermistor

Abstract

The electrical properties of the grain boundary region of electroceramic sensor temperature based on inverse spinel Zn 7 Sb 2 O 12 were investigated at high temperature. The zinc antimoniate was synthesized by a chemical route based on the modified Pechini method. The electric properties of Zn 7 Sb 2 O 12 were investigated by impedance spectroscopy in the frequency range from 5 Hz to 13 MHz and from 250 up to 600°C. The grain boundary conductivity follows the Arrhenius law, with two linear branches of different slopes. These branches exhibit activation energies with very similar values; the low-temperature ͑р350°C͒ and high-temperature ͑у400°C͒ regions are equal to 1.15 and 1.16 eV, respectively. Dissimilar behavior is observed on the relaxation time ͑͒ curve as a function of temperature, where a single slope is identified. The negative temperature coefficient parameters and nature of the polarization phenomenon of the grain boundary are discussed.

Dielectric Property of Polycrystalline ZrO<SUB>2</SUB> Substituted BaTi<SUB>2</SUB>O<SUB>5</SUB> Prepared by Arc-Melting

“…The discrepancy of these peak frequencies has been often reported. 20,21) Some defect structure by the rapid quenching or the second phase by the partial decomposition may cause the discrepancy of the peak frequencies. At y ¼ 0:060 the difference of peak frequencies of Z 00 and M 00 was more pronounced than that at y ¼ 0:008, which may be caused of the increase in the second phase (as shown in Fig.…”

Conductivity mechanism analysis at high temperature in bismuth titanate: A single crystal with sillenite-type structure

“…Recently, NTC thermistors based on the polycrystalline antimoniate with structure type spinel or pyrochlore have been reported at high temperature. 8,9 Interesting thermistor parameters have been reported for Zn 7 Sb 2 O 12 and Bi 3 Zn 2 Sb 3 O 14 ceramics, which were derived from analysis of impedance spectroscopy measurements. [8][9][10] Bi 12 TiO 20 single crystal was grown by the pulling techniques, using a resistive heating furnace and pure platinum crucibles.…”

“…8,9 Interesting thermistor parameters have been reported for Zn 7 Sb 2 O 12 and Bi 3 Zn 2 Sb 3 O 14 ceramics, which were derived from analysis of impedance spectroscopy measurements. [8][9][10] Bi 12 TiO 20 single crystal was grown by the pulling techniques, using a resistive heating furnace and pure platinum crucibles. The starting batch melt was prepared by thoroughly mixing an appropriate amount of bismuth oxide and titanium oxide, followed by melting at temperature ranging from 900 to 950°C.…”

Dielectric Properties of Ba<SUB>1&minus;<I>x</I></SUB>Ca<I><SUB>x</SUB></I>Ti<SUB>2</SUB>O<SUB>5</SUB> Prepared by Arc Melting

“…However, a discrepancy is often observed due to a slightly distributed , mainly resulting from a defect structure; the greater the discrepancy, the greater the defect. 23) In the present study, the discrepancy was minimal, suggesting a less defect structure, even with a significant amount of the Ca substitution, x ¼ 0:10. Figure 4 shows the temperature dependence of the permittivity of BCT 2 .…”