Chemically Tailorable Frustrated Systems, Magnetic order in the J1/J1’ rectangular lattice

This proposal forms part of an exploratory study of new mixed anion coordination compounds. We have prepared a family of oxalate-fluorides, which are anticipated to have frustrated magnetic properties due to competing interactions mediated via the oxalate and fluoride ligands. Two of these compounds have composition CsM(C2O4)F, where M = Co or Fe. They have a simple crystal structure based on 'rectangular' layers, where the sides of the rectangle represent different chemical 'bridges' between magnetic centres: fluoride or oxalate bridges. They show similar, but distinct magnetic properties, with evidence for low-dimensional magnetic interactions, followed at lower temperature, by a more abrupt magnetic anomaly for the Co compound. We aim to explore the possibly ordered magnetic state of these compounds at lower temperature.

本研究提案属于新型混合阴离子配位化合物（mixed anion coordination compounds）探索性研究的组成部分。我们已合成一类草酸根-氟根混合配体配位化合物（oxalate-fluorides），鉴于草酸根与氟根配体（ligands）介导的竞争性相互作用，该类化合物预计将呈现阻挫磁性（frustrated magnetic properties）。其中两种化合物的化学式为CsM(C₂O₄)F，其中M分别为钴（Co）或铁（Fe）。该类化合物具有基于“矩形”层状结构的简单晶体构型，矩形的侧边对应磁性中心（magnetic centres）之间的两类化学桥联（bridges）：氟根桥联与草酸根桥联。二者展现出相似却各具特色的磁学特性，均存在低维磁相互作用（low-dimensional magnetic interactions）的特征；在更低温度区间，钴基化合物会出现更为突兀的磁反常现象（magnetic anomaly）。本研究旨在探究这两类化合物在更低温度下可能存在的有序磁态（ordered magnetic state）。