Preparation of La-modified PbTiO3 thin films on the oxide buffer layers with NaCl-type structure

Abstract

La‐modified PbTiO₃(PLT: Pb_0.9La_0.1Ti_0.975O₃) thin films by rf magnetron sputtering were prepared on the preferred (100)‐oriented oxide buffer layers with NaCl‐type structure, which were prepared by plasma‐enhanced metalorganic chemical vapor deposition. Fused silica, (111)Si, soda‐lime glass, and stainless steel were used as the substrates to prepare the oxide buffer layers. The c‐axis and a‐axis preferred oriented PLT thin films were obtained on the buffer layer, independent of the kind of substrate. Further, highly c‐axis oriented PLT thin films were obtained when the substrate had a large thermal expansion coefficient. Significant pyroelectric currents were detected without a poling treatment. The NiCr/PLT/(100)Pt/(100)MgO/stainless steel structure had a dielectric constant of 250, a dielectric loss factor tan δ of 0.8%, and a pyroelectric coefficient of 3.8×10⁻⁴ C/m² K.