Multiferroic Aurivillius Bi4Ti2-xMnxFe0.5Nb0.5O12 (n = 3) compounds with tailored magnetic interactions.
Multiferroic Aurivillius Bi4Ti2-xMnxFe0.5Nb0.5O12 (n = 3) compounds with tailored magnetic interactions.
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具有定制磁相互作用的多铁 Aurivilius Bi4Ti2-xMnxFe0.5Nb0.5O12 (n = 3) 化合物。
DOI：
10.1039/d1dt02220b
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Algueró M
中科院分区：
文献类型：
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作者：
Algueró M
具有通式（Bi 2 O2）（An− 1BnO 3 n +1）的Aurivillius化合物是一个高度热门的功能层状氧化物家族，目前正在研究室温多铁性。化学设计策略是将磁活性BiMO 3单元（M：Fe 3+，Mn 3+，Co 3 +...）结合到已知铁电体如Bi 4 Ti 3 O 12的伪钙钛矿层中，引入额外的氧八面体。或者，可以尝试直接用磁性物质替代钙钛矿板中的Ti 4+。以前的报告探索了M3+物质的引入，这需要同时掺入5+阳离子，如Bi 4 Ti 3 − 2xNbxFexO 12系统。如果Ti 4+被Mn 4+取代，则可以获得更大的磁性分数，尽管已经认为小的离子半径阻止其并入伪钙钛矿层中。我们在这里报告了Aurivillius Bi 4 Ti 2 −xMnxNb0.5Fe0.5O12（n = 3）化合物的机械合成，其中Mn 4+含量增加到x = 0.5，这对应于B位超过逾渗阈值的1/3的磁性分数，以及等量的Mn 4+和Fe 3+。铁磁超交换相互作用和磁有序的出现是预期的，并显示为x ≥ 0.3的相。陶瓷加工是通过火花等离子体烧结完成的，这使得能够进行电气测量，证明所有含Mn 4+的Aurivillius化合物的铁电性。这是一个新的层状氧化物家族，也是一种有前途的单相多铁性替代方法。
Aurivillius compounds with the general formula (Bi2O2)(An−1BnO3n+1) are a highly topical family of functional layered oxides currently under investigation for room-temperature multiferroism. A chemical design strategy is the incorporation of magnetically active BiMO3 units (M: Fe3+, Mn3+, Co3+ …) into the pseudo-perovskite layer of known ferroelectrics like Bi4Ti3O12, introducing additional oxygen octahedra. Alternatively, one can try to directly substitute magnetic species for Ti4+ in the perovskite slab. Previous reports explored the introduction of the M3+ species, which required the simultaneous incorporation of a 5+ cation, as for the Bi4Ti3−2xNbxFexO12 system. A larger magnetic fraction might be attained if Ti4+ is substituted with Mn4+, though it has been argued that the small ionic radius prevents its incorporation into the pseudo-perovskite layer. We report here the mechanosynthesis of Aurivillius Bi4Ti2−xMnxNb0.5Fe0.5O12 (n = 3) compounds with increasing Mn4+ content up to x = 0.5, which corresponds to a magnetic fraction of 1/3 at the B-site surpassing the threshold for percolation, and equal amounts of Mn4+ and Fe3+. The appearance of ferromagnetic superexchange interactions and magnetic ordering was anticipated and is shown for phases with x ≥ 0.3. Ceramic processing was accomplished by spark plasma sintering, which enabled electrical measurements that demonstrated ferroelectricity for all Mn4+-containing Aurivillius compounds. This is a new family of layered oxides and a promising alternative single-phase approach for multiferroism.