Structural and electrical properties of heavy rare-earth zirconate

摘要

The synthesis, characterization and electrical properties of Tb2Zr2O7 compound have been studied. The heavy rare earth zirconate were prepared by solid state reaction technique and characterized by XRD, differential thermal analysis (DTA), thermogravimetric analysis (TGA) and derivative thermogravimetry (DTG). The XRD characterization shows the formation of single phase orthorhombic structure at room temperature. The electrical conductivity of Tb2Zr2O7 compound was measured in the temperature range 300-1125 K at an internal frequency of 1kHz. The logσ vs 103/T plot yield two different slopes separated by break temperature (T1). The activation energy below and above this break temperature have been estimated as 0.13eV and 3.4eV respectively. Hence the electrical conduction below T1 is essentially extrinsic always associated with impurities, defects and interstitials and conduction above T1 is essentially intrinsic due to the change in conduction mechanism.