In the present work, we aim to achieve the preferred crystal orientation of chemical solution deposition (CSD)-derived BaTiO3 films on ubiquitous Si wafers with the assistance of Ca2Nb3O10 nanosheet (ns-CN) template layers. The ns-CN on platinized Si (Pt/Si) substrates aligned the BaTiO3(100) plane to the substrate surface, because of the favorable lattice matching of the ns-CN (001) plane. The CSD process in air required a high crystallization temperature of 900 °C for the preferred crystal orientation of BaTiO3(100) because of the BaCO3 byproduct generated during the combustion reaction of the precursor gel. The processing in vacuum to remove CO2 species enhanced the crystal orientation even at the crystallization temperature of 800 °C, although it can generate oxygen vacancies ( ) that cause distorted polarization behavior under an applied field higher than approximately 150 kV/cm. The relative dielectric constant (εr) of the (100)-oriented BaTiO3 film on the ns-CN-supported Pt/Si substrate (ns-CN/Pt/Si) was generally larger than that of the randomly oriented film on Pt/Si, depending on the degree of crystal orientation.

Thin films of the BaTiO 3 -Bi(Mg 1/2 Ti 1/2 )O 3 (BT-BMT) solid-solution system were fabricated with the aim of achieving a stable temperature coefficient of capacitance (TCC) favorable for high-temperature electronics. A single perovskite phase with pseudocubic symmetry was obtained for the films fabricated by chemical solution deposition on (111)Pt/TiO 2 /(100)Si substrates in the composition range of x = 0-0.80 for (1 % x)BT-xBMT. BMT added to the BaTiO 3 -based films enhanced the crystallinity of the perovskite phase and resulted in saturated P-E hysteresis behavior with remanent polarization of up to 13 µC/cm 2 . BMT addition led to gradual dielectric relaxation, which also resulted in stable TCC behavior with a relative dielectric constant of approximately 400 in the temperature range of RT % 400 °C, especially for the BT-BMT films with x = 0.20-0.40.

Thin films of the BaTiO 3 Bi(Mg 1/2 Ti 1/2 )O 3 (BTBMT) solid-solution system with preferential crystal orientation of (100) and (111) plane were fabricated on (100)SrRuO 3 //(100)SrTiO 3 and (111)SrRuO 3 //(111)SrTiO 3 substrates by CSD technique. Enhanced dielectric permittivity (¾ r ) of approximately 800 was confirmed for the (111)-oriented BTBMT film at room temperature, which is significantly larger than those of (100)-or randomly-oriented films. The BTBMT films exhibited relatively stable temperature coefficient of capacitance (TCC) independent of their crystal orientation, that allows enhanced ¾ r up to 400°C without drastic change of the capacitance. These properties can be favorable for the application of dielectric capacitors in hightemperature electronics.