Resistivity Behavior of Semiconducting YBaZrTiO 3

The influence of Zr additions and oxygen pressure on the NTC and PTC characteristics of YBaTiO 3 over the temperature range from -50° to +150°C was determined. The NTC behavior of doped YBaTiO 3 depended upon the effect of the Zr dopant on the crystallographic phase transitions. The room temperature resistivity and the switching temperature were controlled by the dopant level and the prevailing oxygen pressure during cooling from the sintering temperature. Temperature coefficients of resistance ranged from -2 to -16%/°C in the NTC region and from +2 to +17%/°C in the PTC region.