A series of bismuth layer-structured ferroelectrics

Abstract

The general formula, Sr _m−3+x Bi_4−x Ti _m−x Ta _x O_3m+3 (m=2 and 3) is a phase relation between well-known bismuth layer-structured ferroelectrics (BLSF) such as Bi₄Ti₃O₁₂ and SrBi₂Ta₂O₉ including a perovskite compound SrTiO₃. The series was discussed to form the layer structure with the numbers m=2 and 3 of layer, where x is the number of Ta ions in the layer structure and 1≦x≦2 for m=2 and 0≦x≦2 for m−3. The Curie temperature, T _c' increase as the Sr concentration decreases. From the measurements of D-E hysteresis loops by using a standard Sawyer-Tower circuit, the value of 2P _r on Sr_0.3Bi_3.7Ta_2.7Ta_0.3O₁₂ (m=3) ceramics was the largest (2P _r=24.6 μC/cm²) in above BLSF series.

Keywords:

• bismuth layer-structured ferroelectrics
• Bi₄Ti₃O₁₂
• SrBi₂Ta₂O₉
• Curie temperature
• D-E hysteresis loop
• fatigue-free