Inhibition of polydomain formation in PbTiO3/PbZr0.2Ti0.8O3 superlattices by intercalation of ultra-thin SrTiO3 layers
Résumé
We used pulsed laser deposition to grow a series of PbTiO3/PbZr0.2Ti0.8O3 superlattices on SrTiO3 and SrRuO3/SrTiO3 substrates. An a/c polydomain structure was evidenced by reciprocal space mapping and by transmission electron microscopy. Insertion of ultra-thin layers of SrTiO3 at the interfaces between PbTiO3 and PbZr0.2Ti0.8O3 layers has inhibited this polydomain formation. A strong decrease in the tetragonality indicates clearly that the polarization state in these superlattices has changed due to the insertion of the SrTiO3 layers. A purely elastic mechanism does not seem to explain the determined structural parameters