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Correlation between high-pressure electrical properties of ZrO2 and its crystallite size

Trefilova A. N., Korionov I. V., Babushkin A. N., Łojkowski W., Opalińska A.

Materials Science Poland

2005

Vol. 23, No. 1

247--252

A relation between crystallite size and electrical properties of ZrO2 has been investigated by measurements of high-pressure electrical resistance. The resistance of nanocrystalline praseodymium-doped zirconia powders has been measured in the pressure and temperature ranges between 15 and 50 GPa, and 77 and 400 K, respectively. Around 30-37 GPa the resistances of all samples decrease by 3-4 orders of magnitude. Therefore, the anomalies in the pressure dependence of the resistance and of parameters depending on the concentration, mobility and activation energy of the charge carriers were found at ca. 40-45 GPa. The activation energy of the charge carriers depends on the crystallite size.

Relaxation processes in ZrO2 at high pressures

Korionov I. V., Trefilova A. N., Babushkin A. N., Łojkowski W., Opalińska A.

Materials Science Poland

2004

Vol. 22, No. 3

241--244

Relaxation processes in ZrO2 have been studied at pressures in the range of 22-50 GPa by measurements of high-pressure electrical relaxation of resistance in time. Electrical relaxation in nanocrystalline praseodymium doped zirconia powders and in a bulk material sample of zirconia has been measured in the pressure range from 35.5 to 50 GPa. The time dependence of electric resistance is most precisely described by exponential function up to the pressure of 35.5-50 GPa. The time dependence of electric resistance is most precisely described by exponential function up to the pressure 44-45.5 GPa. After treatment the pressure higher than 45.5 GPa, the character of the relaxation changes and resistance increased with time. Relaxation processes have not been observed in ZrO2 with 56 nm crystallite sizes.