Epitaxial growth of high dielectric constant lead-free relaxor ferroelectric for high-temperature operational film capacitor

Abstract An epitaxial thin-film capacitor based on relaxor ferroelectric oxide, BaTiO 3 –Bi(Mg 2/3 Nb 1/3 )O 3 (BT–BMN), has been realized on Nb:SrTiO 3 substrates. A high dielectric constant exceeding 400 was attained on high-temperature annealed films at frequencies below 100 kHz. BT–BMN thin-film exhibited a broad dielectric constant variation against temperature and also the frequency dependent dielectric-constant-maximum temperature. Excellent dielectric constant stability below 10% was achieved in 75–400 °C temperature range with a low dielectric loss. This exemplifies BT–BMN as a dielectric for monolithically integrated capacitors that can function up to 400 °C, breaking the present 175 °C limit of bulky capacitors, in high-power high-temperature electronic devices.