title: Giant dielectric permittivity observed in Li and Ti doped NiO.
abstract: A giant low-frequency dielectric constant ( epsilon 0 approximately 10(5)) near room temperature was observed in Li,Ti co-doped NiO ceramics. Unlike currently best-known high epsilon 0 ferroelectric-related materials, the doped oxide is a nonperovskite, lead-free, and nonferroelectric material. It is suggested that the giant dielectric constant response of the doped NiO could be enhanced by a grain boundary-layer mechanism as found in boundary-layer capacitors. In addition, there is about a one-hundred-fold drop in the dielectric constant at low temperature. This anomaly is attributed to a thermally excited relaxation process rather than a thermally driven phase transition, as for that yielding ferroelectrics.
authors.affiliation: Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Junbo
authors.initials: J
authors.lastname: Wu
authors.forename: Ce-Wen
authors.initials: CW
authors.lastname: Nan
authors.forename: Yuanhua
authors.initials: Y
authors.lastname: Lin
authors.forename: Yuan
authors.initials: Y
authors.lastname: Deng