Thermal conductivity of SrBi_2Nb_2O_9 ferroelectric thin films

摘要

Ferroelectric Aurivillius SrBi_2Nb_2O_9 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 SrBi_2Nb_2O_9 films was measured in the 100-300 K temperature range by the 3ω 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 SrBi_2Nb_2O_9 sample, in the 10-300 K temperature range, led to identical conclusions. The origin of this unexpected glasslike behavior is discussed.