Multiferroism Induced by Spontaneous Structural Ordering in Antiferromagnetic Iron Perovskites
Multiferroism Induced by Spontaneous Structural Ordering in Antiferromagnetic Iron Perovskites
复制标题
DOI：
10.1021/acs.chemmater.9b02716
复制
发表时间：
2019-08-13
影响因子：
8.6
通讯作者：
Garcia-Martin, Susana
中科院分区：
文献类型：
--
作者：
Martinez de Irujo-Labalde, Xabier;Goto, Masato;Garcia-Martin, Susana
首次报道了多晶反铁磁Fe钙钛矿的室温多铁性。在钙钛矿型氧化物RE_（1.2）Ba_（1.2）Ca_（0.6）Fe_（3 O_8）（RE = Gd，Tb）中，Gd（Tb）、Ba和Ca原子的层状有序与FeO_（4-）四面体（T）和FeO_（6-）八面体（O）有序的相互作用导致了极性晶体结构。层状结构由RE/Ca-RE/Ca-Ba-RE/Ca层的堆叠序列与单元晶胞中的TOOT序列组合组成。Gd氧化物的极距为33.0 μ C/cm（2）（Tb氧化物的极距为23.2 μ C/cm（2））是由阳离子（主要是Fe）和氧原子沿着b轴的位移确定的。这些氧化物呈现出反铁磁有序，使c轴加倍，并且Tb化合物中的磁性结构保持高达690 K，这是Fe钙钛矿中报道的最高转变温度之一。
Room-temperature multiferroism in polycrystalline antiferromagnetic Fe perovskites is reported for the first time. In the perovskite-type oxides RE1.2 Ba1.2Ca0.6Fe3O8 (RE = Gd, Tb), the interplay of layered ordering of Gd(Tb), Ba, and Ca atoms with the ordering of FeO4-tetrahedra (T) and FeO6 -octahedra (O) results in a polar crystal structure. The layered structure consists of the stacking sequence of RE/Ca-RE/Ca-Ba-RE/Ca layers in combination with the TOOT sequence in a unit cell. A polar moment of 33.0 mu C/cm(2) for the Gd-oxide (23.2 mu C/cm(2) for the Tb one) is determined from the displacements of the cations, mainly Fe, and oxygen atoms along the b-axis. These oxides present antiferromagnetic ordering doubling the c-axis, and the magnetic structure in the Tb-compound remains up to 690 K, which is one of the highest transition temperatures reported in Fe perovskites.