探索低維與頓挫系統中多鐵電物質的基本參數(台俄國際合作計畫)

Abstract

多鐵電材料為近年來凝態物理界新興起的課題之一。多鐵電材料指物質 中存在兩者以上的有序性（如鐵電性、鐵磁性、反鐵磁性等）。這些物質中 為何電性、磁性、與晶格會如此強烈的交互作用，是學界熱切討論的問題。 這些多鐵電材料因為可以用磁性控制電性，或是用電性控制磁性，因此極 有潛力應用於未來的尖端電子元件中。以往這些被研究的材料多集中於錳 氧化物中；本計劃將專注研究非錳氧化物中，低維度與具頓挫性物質中的 多鐵電相關特性，從其中發現新的多鐵電材料，並詳細測量其物理特性與 基本物質參數。 材料上，我們將著重單晶的成長。在測量上，我們將應用磁性、電 性、電介係數、比熱、光譜等實驗來了解這些新穎物質的材料特性。

Multiferroics has been a newly raised interest in condensed matter physics. Multiferroics are characterised by the coexistence of at least two order parameters in the magnetic, electric or elastic subsystems. It is still under hot debates what mechanism leads to such strong and intriguing interactions between spins, charges and the lattices. Furthermore, with multiferroics, there are more degrees of freedom for the control and manipulation of the electronic devices made of multiferroic materials. This makes multiferroic materials promising for advanced technologies. Previous and current studies of multiferroics have been much focused on the compounds of manganites. In this proposal, on the other hand, we shall intensively investigate the low dimensional and frustrated metal oxides. The aims are to find the new multiferroic materials and to comprehensively characterize the mulitiferroics in these materials. The search and study of fundamental parameters of new multiferroic materials are emphasized through the whole project. To summarize, (1) the single crystals growth of the novel low dimensional and frustrated metal oxides is to be developed to search for new multiferroic materials; (2) characterizations of these new materials and the understanding of their physical properties will be realized through the experiments of the magnetic properties, electric transport properties, dielectrics, specific heat, and spectroscopy.