Anomalous dielectric peak in Mg and Li doped ZnO ceramics and thin films

In this manuscript we report dielectric measurements of Mg and Li doped ZnO ceramics and thin films of various compositions. We have tried to reproduce the reported ferroelectriclike behavior in doped ZnO ceramics and thin films and observed anomalous dielectric peak in our samples at temperatures similar to the reported data. However, this peak disappeared when the same samples were measured in vacuum. Our results suggest that previously reported anomalous dielectric peak in doped ZnO samples is not related to the ferroelectric phase transition and is a measurement artifact originated from the presence of water vapor in the measurement system. (C) 2010 American Institute of Physics. [doi:10.1063/1.3505930]