Structure-composition-property relationships in complex ACu3B4O12 perovskites

我们实验室的初步结果表明，钙钛矿相关化合物中的两个成员(CaCu3Ti4O12，CCTO和Na1/2Bi1/2Cu3Ti4O12)在低温下具有高的本征介电常数(&gt；100)，适当的掺杂(掺入Mn)可以在室温下制备出具有良好的微波介电谐振性能的陶瓷。较大的本征介电常数表明，除了离子极化在这些化合物中起着重要作用外，还有某种(尚不清楚)形式的额外极化，而且ACu3Ti4O12类型的材料在适当的化学掺杂后具有基本有趣的介电行为和潜在的有用的块状介电性能。因此，本研究的目的是制备和表征各种类型的未掺杂和掺锰的ACu3B4O12型化合物，以建立它们的结构-组成-性质关系。将特别强调优化块体的介电性能，以评估其作为商业有用的高介电常数和/或温度稳定的介电材料的潜力。

Preliminary results in our laboratory have shown two members (CaCu3Ti4O12, CCTO, and Na1/2Bi1/2Cu3Ti4O12) from a large family of perovskite-related compounds based on the general formula ACu3B4O12 have high intrinsic permittivity (> 100) at low temperatures and that appropriate doping (with Mn) can produce ceramics with encouraging microwave dielectric resonance properties at room temperature. The large values of intrinsic permittivity suggests some (as yet unknown) form of additional polarisation, other than ionic polarisation plays an important role in these compounds and that ACu3Ti4O12-type materials possess fundamentally interesting dielectric behaviour and potentially useful bulk dielectric properties after appropriate chemical doping. The aim of this study is therefore to prepare and characterise a wide variety of undoped and Mn-doped ACu3B4O12-type compounds to establish their structure-composition-property relationships. Particular emphasis will be given to optimising the bulk dielectric properties to assess their potential as commercially-useful high permittivity and/or temperature-stable dielectrics.