在BaFe2(PO4) 2中的结构回流过渡过程中:二维铁磁的影响
Rénald David1, Alain Pautrat, Dmitry Filimonov
1Université Lille Nord de France, UCCS, UMR-CNRS 8181, ENSCL-USTL, Villeneuve d'Ascq, France.
Journal of the American Chemical Society
|August 24, 2013
概括
酸铁,BaFe2(PO4) 2,是第一个2D Ising铁磁氧化物. 它表现出一个独特的回入结构过渡接近其库里温度,由磁性排序和Jahn-Teller不稳定性驱动.
科学领域:
- 材料科学 材料科学 材料科学
- 固态物理 固态物理
- 磁力学 磁力学 是一种
背景情况:
- 二维 (2D) 材料提供独特的物理特性,由于减少了维度.
- 具有磁性排序的氧化物材料对自旋电子应用具有重大兴趣.
- 氧化物中的铁磁性是罕见的,这使得新的发现非常有价值.
研究的目的:
- 合成和描述BaFe2(PO4)2作为一种新的2D Ising铁磁氧化物.
- 为了研究BaFe2的结构和磁性相位过渡, BaFe2(PO4)2.2.
- 了解晶体结构,Jahn-Teller扭曲和磁性质之间的相互作用.
主要方法:
- 用于材料制备的热水合成.
- 用X射线衍射来确定晶体结构.
- 莫斯巴乌尔光谱和电子磁共振 (EPR) 用于磁性表征.
- 密度函数理论 (DFT) 计算用于能源估计.
主要成果:
- BaFe2(PO4)2被确定为第一个2D Ising铁磁氧化物,具有FeO6八面体的蜂层.
- 从三角向三临床 (P-1) 的结构过渡发生在140K以下,这是由于Jahn-Teller的不稳定性.
- 在70K以下观察到一种罕见的重返性结构过渡到三角形 (R-3),与铁磁排序 (Tc = 65.5K) 相吻合.
- 莫斯巴乌尔光谱学揭示了四极分裂中不连续的变化,与结构转变相关.
- EPR证实了单轴磁性异构性和Tc.以上磁域的存在.
结论:
- BaFe2(PO4)2 呈现出 Jahn-Teller 扭曲和二维 Ising 铁磁之间的复杂相互作用.
- 重返的结构转变是一种与磁性排序相关的独特现象.
- 这种材料可以作为研究氧化物中二维Ising磁性的模型系统.
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