Phase transitions and relaxor behavior of lead-free ferroelectric bismuth potassium titanate

チタン酸ビスマスカリウムの相転移とリラクサー挙動

斎藤 幸太郎*; 松尾 拓紀*; 米田 安宏   ; Ye, Z.-G*; 野口 祐二*

Saito, Kotaro*; Matsuo, Hiroki*; Yoneda, Yasuhiro; Ye, Z.-G*; Noguchi, Yuji*

The phase transition behavior of relaxor ferroelectric BiKTiO (BKT) is investigated in ceramic from based on synchrotron radiation X-ray diffraction measurements and dielectric measurements as a function of temperature. The structural transformation from the cubic non-ergodic (NER) relaxor state to the tetragonal NER state triggers the spontaneous relaxor-to-ferroelectric phase transition. Based on the experimental observations, a temperature phase diagram of BKT is established in terms of average crystal structure and polar order.