Structural and dielectric properties of epitaxial (Ba,Sr)TiO3 films on c-Al2O3 with ultra-thin TiN sacrificial template

Abstract

Using ultra-thin TiN sacrificial template, the epitaxial (Ba,Sr)TiO 3 [BST] films on c-Al 2 O 3 were grown by pulsed laser deposition. TiN epitaxially grew on c-Al 2 O 3 with (111) orientation, which promoted the (111) epitaxial growth of upper BST films. The obtained epitaxial BST films showed significantly larger dielectric constant compared with polycrystalline films directly deposited on c-Al 2 O 3 over the wide temperature range. By inserting the TiN template, the temperature corresponding to maximum dielectric constant of BST films was shifted up by 50 K, which is mainly due to the in-plane tensile strain induced by the difference in thermal expansion coefficients of BST and c-Al 2 O 3 .

Strain-Stable Nonlinear Dielectric Responses in Pyrochlore Bismuth Zinc Niobate Thin Films

“…Q ijk à and Q ijk Ãà are the orientation-dependent coefficients of the films with the ijk orientation, which include electrostrictive constants. Q ijk à and Q ijk Ãà with the (111) orientation are defined as 34)…”