Baghizadeh Ali, Vaghefi Pegah Mirzadeh, Huang Xing, Borme Jerome, Almeida Bernardo, Salak Andrei N, Willinger Marc-Georg, Amaral Vitor B, Vieira Joaquim M
Department of Materials and Ceramics Engineering, CICECO - Aveiro Institute of Materials, University of Aveiro, Aveiro, 3810-193, Portugal.
Scientific Center for Optical and Electron Microscopy (ScopeM), ETH Zurich, Zurich, 8093, Switzerland.
Small. 2021 Mar;17(11):e2005700. doi: 10.1002/smll.202005700. Epub 2021 Feb 23.
Multiferroic materials demonstrating coexistence of magnetic and ferroelectric orders are promising candidates for magnetoelectric devices. While understanding the underlying mechanism of interplaying of ferroic properties is important, tailoring their properties to make them potential candidates for magnetoelectric devices is challenging. Here, the antiferromagnetic Neel ordering temperature above 200 K is realized in successfully stabilized epitaxial films of (Lu,Sc)FeO multiferroic oxide. The first-principles calculations show the shrinkage of in-plane lattice constants of the unit cells of the films on different substrates which corroborates well the enhancement of the Neel ordering temperature (T ). The profound effect of lattice strain/stress at the interface due to differences of in-plane lattice constants on out of plane magnetic properties and on spin reorientation temperature in the antiferromagnetic region is further elucidated in the epitaxial films with and without buffer layer of Mn-doped LuFeO . Writing and reading ferroelectric domains reveal the ferroelectric response of the films at room temperature. Detailed electron microscopy shows the presence of lattice defects in atomic scale. First-principles calculations show that orbital rehybridization of rare-earth ions and oxygen is one of the main driving force of ferroelectricity along c-axis in thin films of hexagonal ferrites.
展示磁有序和铁电有序共存的多铁性材料是磁电器件很有前景的候选材料。虽然理解铁性特性相互作用的潜在机制很重要，但调整它们的特性使其成为磁电器件的潜在候选材料具有挑战性。在此，在成功稳定的（镥，钪）铁酸镧多铁性氧化物外延薄膜中实现了高于200K的反铁磁尼尔有序温度。第一性原理计算表明，不同衬底上薄膜晶胞的面内晶格常数收缩，这与尼尔有序温度（T）的提高很好地相符。在有和没有锰掺杂镥铁酸镧缓冲层的外延薄膜中，进一步阐明了由于面内晶格常数差异导致的界面处晶格应变/应力对平面外磁性能和反铁磁区域自旋重取向温度的深远影响。写入和读取铁电畴揭示了薄膜在室温下的铁电响应。详细的电子显微镜显示了原子尺度上晶格缺陷的存在。第一性原理计算表明，稀土离子和氧的轨道再杂化是六方铁氧体薄膜中沿c轴铁电性的主要驱动力之一。
