Electric field–temperature phase diagram of sodium bismuth titanate-based relaxor ferroelectrics
Electric field–temperature phase diagram of sodium bismuth titanate-based relaxor ferroelectrics
复制标题
DOI：
10.1007/s10853-018-2232-5
复制
发表时间：
2018-03
影响因子：
4.5
通讯作者：
Florian Weyland;M. Acosta;Malte Vögler;Yoshitaka Ehara;J. Rödel;N. Novak
中科院分区：
文献类型：
--
作者：
Florian Weyland;M. Acosta;Malte Vögler;Yoshitaka Ehara;J. Rödel;N. Novak
报道了钛酸铋钠基弛豫铁电体0.94（Na_（1/2）Bi_（1/2）TiO_3）-0.06（BaTiO_3）、0.80（Na_（1/2）Bi_（1/2）TiO_3）-0.20（K_（1/2）Bi_（1/2）TiO_3）和0.75（Na_（1/2）Bi_（1/2）TiO_3）-0.25（SrTiO_3）的电场-温度相图。弛豫行为表现出温度依赖性的介电常数测量在非极化和极化状态，以及由场致相变到铁电相从弛豫相。通过变温测温，确定了铁电相变的阈值电场，并得到了相变释放的潜热。我们确定的非遍历和遍历弛豫相的温度范围的基础上的存在或不存在的可逆性的弛豫铁电过渡。对于所有三种组合物，电场-温度相图被构建，并确定了一个临界点。所构建的电场-温度相图有助于找到机电和电热应用的铁电体和弛豫体的最佳操作范围。
The electric field–temperature phase diagrams of three bismuth sodium titanate-based relaxor ferroelectrics are reported, namely 0.94(Na1/2Bi1/2TiO3)–0.06(BaTiO3), 0.80(Na1/2Bi1/2TiO3)–0.20(K1/2Bi1/2TiO3) and 0.75(Na1/2Bi1/2TiO3)–0.25(SrTiO3). Relaxor behavior is demonstrated by temperature-dependent dielectric permittivity measurements in the unpoled and poled states, as well as by the field-induced phase transition into a ferroelectric phase from the relaxor phase. From temperature-dependent thermometry measurements, we identified the threshold electric field to induce the ferroelectric phase and obtained the released latent heat of the phase transition. We determined the nonergodic and ergodic relaxor phase temperature range based on the absence or presence of reversibility of the relaxor to ferroelectric transition. For all three compositions, the electric field–temperature phase diagram was constructed and a critical point was identified. The constructed electric field–temperature phase diagrams are useful to find optimum operational ranges of ferroelectrics and relaxors for electromechanical and electrocaloric applications.