Thermal conductivity of SrBi2Nb2O9 ferroelectric thin films

Ferroelectric Aurivillius SrBi2Nb2O9 films of different thicknesses were prepared on Si(100) substrates by pulsed laser deposition. The films are polycrystalline and exhibit an increased grain size with film thickness. The cross-plane thermal conductivity of such SrBi2Nb2O9 films was measured in the 100-300 K temperature range by the 3 omega method and it was observed that the thermal properties of this family of ferroelectric materials show a glasslike behavior. The measurements performed on a polycrystalline bulk SrBi2Nb2O9 sample, in the 10-300 K temperature range, led to identical conclusions. The origin of this unexpected glasslike behavior is discussed. (c) 2006 American Institute of Physics.