[18p-E317-1~11] 9.1 Dielectrics, ferroelectrics

[18p-E317-10] Anti-Polar States and Dielectric Property under Electric Field in Tetragonal Tungsten Bronze K₂RNb₅O₁₅ (R : rare earths)

〇Tomoki Murata¹, Hirofumi Akamatsu², Daisuke Hirai¹, Fumiyasu Oba³, Sakyo Hirose¹ (1.Murata Manufacturing, 2.Kyushu Univ., 3.Tokyo Tech.)

Keywords:dielectric, antiferroelectric, capacitor

Multilayer ceramics capacitors, which are widely used in electronics, are mostly made of ferroelectric BaTiO₃ which has a high dielectric constant. The dielectric constant of ferroelectric BaTiO₃, however, drastically decreases under DC electric field. This motivate us to search for a new candidate of antiferroelectric material, where the dielectric cosntant increases under DC electric field. In this research, we focus on a new class of lead-free AFE material based on K₂RNb₅O₁₅ (R: rare earth) with tetragonal tungsten bronze structure. The dielectric property under high electric field and predicted structures from first principles will be reported.