Karpinsky Dmitry V, Silibin Maxim V, Zhaludkevich Dmitry V, Latushka Siarhei I, Sikolenko Vadim V, Többens Daniel M, Sheptyakov Denis, Khomchenko Vladimir A, Belik Alexei A
Laboratory of Technology and Physics of Crystals Growth, Scientific-Practical Materials Research Centre of NAS of Belarus, 220072 Minsk, Belarus.
Institute for Advanced Materials and Technologies, National Research University of Electronic Technology "MIET", 124498 Zelenograd, Russia.
Materials (Basel). 2021 Oct 4;14(19):5805. doi: 10.3390/ma14195805.
The crystal structure of BiMnO ceramics has been studied as a function of nominal oxygen excess and temperature using synchrotron and neutron powder diffraction, magnetometry and differential scanning calorimetry. Increase in oxygen excess leads to the structural transformations from the monoclinic structure () to another monoclinic (), and then to the orthorhombic () structure through the two-phase regions. The sequence of the structural transformations is accompanied by a modification of the orbital ordering followed by its disruption. Modification of the orbital order leads to a rearrangement of the magnetic structure of the compounds from the long-range ferromagnetic to a mixed magnetic state with antiferromagnetic clusters coexistent in a ferromagnetic matrix followed by a frustration of the long-range magnetic order. Temperature increase causes the structural transition to the nonpolar orthorhombic phase regardless of the structural state at room temperature; the orbital order is destroyed in compounds BiMnO (δ ≤ 0.14) at temperatures above 470 °C.
利用同步加速器和中子粉末衍射、磁强计和差示扫描量热法，研究了BiMnO陶瓷的晶体结构随名义氧过量和温度的变化。氧过量的增加导致结构从单斜结构（）转变为另一种单斜结构（），然后通过两相区域转变为正交结构（）。结构转变的顺序伴随着轨道有序的改变，随后轨道有序被破坏。轨道有序的改变导致化合物的磁结构从长程铁磁态重排为混合磁态，其中反铁磁团簇共存于铁磁基体中，随后长程磁序受挫。温度升高会导致结构转变为非极性正交相，而与室温下的结构状态无关；在温度高于470°C时，化合物BiMnO（δ≤0.14）中的轨道有序被破坏。
