在Eu1-xLaxFe3(BO3)4 (x = 0, 0.18) 中的结构和磁性相变
Ekaterina S Smirnova1, Kirill V Frolov1, Ekaterina V Sidorova1
1Shubnikov Institute of Crystallography of National Research Centre `Kurchatov Institute', Moscow 119333, Russian Federation.
概括
这项研究揭示了EuFe3(BO3) 4在89K以下的结构阶段过渡,在胺多变体中不存在. 这两种化合物都表现出负热膨胀,而La-doping影响了反铁磁排序.
科学领域:
- 材料科学 材料科学 材料科学
- 固态物理 固态物理
- 晶体学 晶体学是指结晶学.
背景情况:
- 稀土铁酸盐是具有复杂结构和磁性特性的多铁化合物.
- 了解相位过渡对于开发新型功能材料至关重要.
研究的目的:
- 调查EuFe3(BO3) 4和Eu0.82La0.18Fe3(BO3) 4.4.3中的结构和磁性特征之间的相关性.
- 在广泛的温度范围内分析这些稀土铁酸盐的相变.
主要方法:
- 单晶X射线衍射 (25-500K) 用于结构分析.
- 特定热量测量 (2.2-101.3 K) 来检测相位过渡.
- 莫斯巴瓦尔光谱 (4.5-298 K) 用于磁性属性分析.
- 进行X射线光分析以确定化学成分.
主要成果:
- 在89K以下的EuFe3(BO3) 4中发现了一个结构相位过渡,涉及原子间距离和角度的扭曲.
- 兰兴奋剂 (Eu0.82La0.18Fe3(BO3) 4) 抑制了结构阶段过渡.
- 由于Fe-Fe距离的增加,这两种化合物均表现出低于90K的负热膨胀.
- 尼尔温度被确定为纯晶体的34.57K和合晶体的32.22K.
- 对于La-doped晶体,建议在ab平面中潜在地违反了反铁磁秩序.
结论:
- 在稀土铁酸盐中,结构和磁性过渡是密切相关的.
- 兰兴奋剂显著影响结构稳定性和磁性排序.
- 该研究提供了对驱动这些材料相变和负热膨胀的机制的见解.
关键词:
莫斯巴乌尔光谱法是使用的.测量热容量 测量热容量测量低温X射线衍射低温X射线衍射负热膨胀是指负的热膨胀.阶段过渡 阶段过渡 阶段过渡稀土铁酸盐是一种稀土铁酸盐.单晶是一种单晶体.固体解决方案 固体解决方案更多相关视频
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