Bi0.8Nd0.2FeO3: a new PbO-free antiferroelectric ceramic

只有少数功能氧化物表现出反极性阳离子位移，可以在环境压力下制造。这些化合物具有NaNbO3或PbZrO3结构，其不同之处在于反极性位移分别沿着假立方钙钛矿电池的边缘和对角线方向。在这两种结构类型中，只有基于pbzro3的化合物显示出在电场作用下在反极性（反铁电）和极性（铁电）状态之间切换的能力，从而产生大的应变和/或电荷。与PbZrO3相关的大极化和应变导致其用作固溶体PbZrO3 - PbTiO3 （PZT）的末端成员，PZT是用于传感器和执行器应用的主要功能陶瓷系统。然而，环境立法管理陶瓷制造使用PbO可能会限制PZT的未来市场。因此，一种具有PbZrO3结构的新型无pbo化合物Bi0.8Nd0.2FeO3的发现非常及时，从基础科学的角度来看具有重要意义，并可能预示着适合器件应用的新一代无pbo陶瓷。该提案旨在了解基于Bi0.8Nd0.2FeO3的材料的基本结构性质关系，并开发适合器件应用的陶瓷

There are only a handful of functional oxides which exhibit antipolar cation displacements that can be fabricated at ambient pressures. Such compounds have either the NaNbO3 or PbZrO3 structure which differ in that the antipolar displacements are along the edges and face diagonals, respectively, of the pseudcocubic perovskite cell. Of these two structural types, only PbZrO3-based compounds, have ever shown the ability to switch between an antipolar (antiferroelectric) and polar (ferroelectric) states under electric field, giving rise to large strain and/or charge. The large polarisation and strain associated with PbZrO3 has resulted in its use as an end members in the solid solution PbZrO3 - PbTiO3 (PZT) which is the main functional ceramic system utilised for sensor and actuator applications. However, environmental legislation governing the fabrication of ceramics using PbO may well limit future markets for PZT. The discovery of a new PbO-free compound, Bi0.8Nd0.2FeO3, with the PbZrO3 structure is therefore extremely timely, of the utmost significance from a fundamental scientific perspective and could herald a new generation of PbO-free ceramics suitable for device applications. The proposal aims to understand the fundamental structure property relations of materials based on Bi0.8Nd0.2FeO3 and to develop ceramics suitable for device applications