Böttcher R, Langhammer H T, Kücker S, Eisenschmidt C, Ebbinghaus S G
Fakultät für Physik und Geowissenschaften, Universität Leipzig, Linnéstraße 5, D-04103 Leipzig, Germany.
J Phys Condens Matter. 2018 Oct 24;30(42):425701. doi: 10.1088/1361-648X/aadea8. Epub 2018 Sep 4.
Electron paramagnetic resonance (EPR) investigations of BaTiO + 0.04 BaO + x/2 FeO (0.007 ⩽ x ⩽ 0.05) ceramics and BaTiFeO single crystals were performed to study the incorporation of Fe ions in the hexagonal 6H-BaTiO lattice and their defect properties. The samples were characterized by x-ray diffraction and wavelength-dispersive x-ray electron probe microanalysis. EPR spectra were recorded both in X- and Q-bands at room temperature. Angle-dependent single crystal EPR investigations and simulations of the ceramic powder EPR spectra revealed three different centers, which can be attributed to Fe ions incorporated on crystallographically different Ti sites. Only one of them was already known before. Two spectra with axial symmetry belong to isolated Fe ions incorporated at Ti(1) sites (exclusively corner-sharing oxygen octahedra) and Ti(2) sites (face-sharing octahedra). The difference of their spectral parameters arises from the different trigonal distortions of the two types of octahedra. The third spectrum has orthorhombic symmetry and is caused by Fe centers associated with a nearest-neighbor charge-compensating oxygen vacancy. A model for the location of this associate is proposed.
对BaTiO + 0.04 BaO + x/2 FeO（0.007⩽x⩽0.05）陶瓷和BaTiFeO单晶进行了电子顺磁共振（EPR）研究，以研究Fe离子在六方6H - BaTiO晶格中的掺入及其缺陷性质。通过X射线衍射和波长色散X射线电子探针微分析对样品进行了表征。在室温下于X波段和Q波段记录了EPR谱。角度相关的单晶EPR研究和陶瓷粉末EPR谱的模拟揭示了三个不同的中心，它们可归因于掺入晶体学上不同Ti位点的Fe离子。其中只有一个以前是已知的。两个具有轴对称性的谱属于掺入Ti(1)位点（仅角共享氧八面体）和Ti(2)位点（面共享八面体）的孤立Fe离子。它们的光谱参数差异源于两种八面体不同的三角畸变。第三个谱具有正交对称性，是由与最近邻电荷补偿氧空位相关的Fe中心引起的。提出了这种缔合体位置的模型。
