纳米晶体Cr3+化BaTiO3的尺寸,组成和相变之间的相互作用,作为矿类氧化物中多铁化的一种途径
Ling Ju1, Tahereh Sabergharesou, Kevin G Stamplecoskie
1Department of Chemistry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1.
Journal of the American Chemical Society
|January 14, 2012
概括
研究人员合成了添加的酸纳米晶体,发现更小的尺寸和更高的兴奋剂促进铁磁性. 这项工作为设计用于高级内存应用的多铁材料提供了一条新的道路.
科学领域:
- 材料科学 材料科学 材料科学
- 凝聚物质物理学 凝聚物质物理学
- 纳米技术 纳米技术
背景情况:
- 多铁子结合了磁极和电极双极的顺序,为先进的记忆器件提供了潜在的潜力.
- 控制纳米晶体属性是定制多铁体行为的关键.
研究的目的:
- 通过使用溶剂控制的方法合成Cr3+) 合的BaTiO3纳米晶体.
- 研究纳米晶体大小和兴奋剂度对结构,相位转换和磁性质的影响.
- 探索创建具有保留铁电和远程磁性排序的多铁材料的潜力.
主要方法:
- 用溶剂控制的合成Cr3+) 合的BaTiO3纳米晶体.
- 用X射线衍射和拉曼光谱进行结构和相位分析.
- 磁性易感度,MCD和XMCD测量用于磁性特性表征.
- 扫描传输X射线显微镜 (STXM) 用于特定元素的磁性分析.
主要成果:
- 降低纳米晶体大小和增加Cr3+) 兴奋剂稳定了平电立方相,尽管铁电四角相仍然存在.
- 已确定Cr3+) 兴奋剂是破坏四旋相稳定的关键因素.
- 纳米晶体膜表现出强大的铁磁排序,由于增强的界面缺陷,纳米晶体尺寸随着较小的纳米晶体尺寸的增加而增加.
- XMCD证实了Cr3+) 交换相互作用是磁性排序的来源.
结论:
- 优化合成的Cr(3+) 合的BaTiO(3) 纳米晶体允许调节的多铁性质.
- 铁电相位保留与远程磁性排序是可以实现的.
- 体纳米晶体作为设计新型多铁矿矿材料的有效基石.
相关概念视频
Crystal Field Theory - Octahedral Complexes
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
Imperfections in Crystal Structure: Non-Stoichiometric Defects
Non-stoichiometric defects refer to a type of defect in the crystal structure of a compound where the ratio of its constituent elements deviates from the ideal stoichiometric ratio. There are two main types of non-stoichiometric defects: metal excess defects and metal deficiency defects.Metal excess defects occur when there is a slight surplus of metal ions than what is required by the stoichiometric ratio of the compound. For example, heating a sodium chloride crystal in sodium vapor results...


