On the correlation between nanoscale structure and magnetic properties in ordered mesoporous cobalt ferrite (CoFe2O4) thin films.
On the correlation between nanoscale structure and magnetic properties in ordered mesoporous cobalt ferrite (CoFe2O4) thin films.
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DOI：
10.1021/nl1014266
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发表时间：
2010-07
期刊：
影响因子：
10.8
通讯作者：
Thomas E Quickel;V. Le;T. Brezesinski;S. Tolbert
中科院分区：
文献类型：
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作者：
Thomas E Quickel;V. Le;T. Brezesinski;S. Tolbert
在这项工作中，我们报告的周期性纳米多孔钴铁氧体（CFO），具有可调的室温亚铁磁性的合成。多孔立方CFO框架是通过无机前体与大的两亲性二嵌段共聚物（称为KLE）的共组装来制造的。反尖晶石骨架具有平均直径为14 nm的有序开放网络孔。的微晶的域的大小是可调的从6到15纳米，这是一个控制，在很小的成本来有序的介观结构。晶畴尺寸的增加与室温结晶度的增加直接相关。此外，这些材料表现出强烈的偏好面外取向的磁化，这是唯一的薄膜系统。该偏好由面内拉伸应变与通过中孔的挠曲的面外应变的松弛相结合来解释。据设想，这种亚铁磁体的孔可以促进形成各种各样的交换耦合复合材料。
In this work, we report the synthesis of periodic nanoporous cobalt ferrite (CFO) that exhibits tunable room temperature ferrimagnetism. The porous cubic CFO frameworks are fabricated by coassembly of inorganic precursors with a large amphiphilic diblock copolymer, referred to as KLE. The inverse spinel framework boasts an ordered open network of pores averaging 14 nm in diameter. The domain sizes of the crystallites are tunable from 6 to 15 nm, a control which comes at little cost to the ordering of the mesostructure. Increases in crystalline domain size directly correlate with increases in room temperature coercivity. In addition, these materials show a strong preference for out-of-plane oriented magnetization, which is unique in a thin film system. The preference is explained by in-plane tensile strain, combined with relaxation of the out-of-plane strain through flexing of the mesopores. It is envisioned that the pores of this ferrimagnet could facilitate the formation of a diverse range of exchange coupled composite materials.