Synthesis of highly transparent lithium ferrite nanoparticle/polymer hybrid self-standing films exhibiting Faraday rotation in the visible region
Synthesis of highly transparent lithium ferrite nanoparticle/polymer hybrid self-standing films exhibiting Faraday rotation in the visible region
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DOI：
10.1021/jp802103d
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发表时间：
2008-09-18
影响因子：
3.7
通讯作者：
Yogo, Toshinobu
中科院分区：
文献类型：
--
作者：
Hayashi, Koichiro;Fujilkawa, Rintaro;Yogo, Toshinobu
在乙基羟乙基纤维素（EHEC）存在下，通过原位水解预聚合的3-烯丙基乙酰丙酮铁（III）（IAA）和丙烯酸锂（LA）来合成锂铁氧体纳米颗粒/EHEC杂化物。该杂化膜是柔性的和自立的，并且在可见光区显示出高的透射率。随着EHEC含量的降低，混合物中锂铁氧体的微晶尺寸从2.7 nm增加到3.8 nm。纳米铁酸锂粒子/EHEC杂化材料在室温下呈现无剩磁的BH曲线。该杂化物具有超顺磁性，阻断温度为13 K.与体相锂铁氧体相比，杂化薄膜的吸收边发生了蓝移。蓝移随着微晶尺寸的减小而增大，这受EHEC的量控制。自支撑膜表现出依赖于磁场的法拉第旋转。比法拉第旋光度（F）对磁场的曲线对应于磁化强度对磁场的曲线。杂化膜的品质因数在700 nm处约为3.5，由于其高透明性，与所报道的铁氧体复合材料在较短波长处的品质因数相比更高。
A lithium ferrite nanoparticle/ethyl(hydroxyethyl)cellulose (EHEC) hybrid was synthesized via in situ hydrolysis of prepolymerized iron(III) 3-allylacetylacetonate (lAA) and lithium acrylate (LA) in the presence of EHEC below 100 degrees C. The hybrid film was flexible and self-standing and showed high transmittance in the visible region. The crystallite size of lithium ferrite in the hybrid increased from 2.7 to 3.8 nm with decreasing amounts of EHEC. Nanosized lithium ferrite particle/EHEC hybrid showed a BH curve with no remanence at room temperature. The hybrid was superparamagnetic with a blocking temperature of 13 K. The absorption edge of the hybrid film was blue-shifted compared with bulk lithium ferrite. The blue-shift increased with decreasing crystallite size, which was controlled by the amount of EHEC. The self-standing film exhibited a Faraday rotation depending upon the magnetic field. The curve for the specific Faraday rotation (F) versus magnetic field corresponded to that for magnetization versus magnetic field. The figure of merit of the hybrid film was about 3.5 at 700 nm, which was higher compared with those of reported ferrite composite at shorter wavelengths, due to its high transparency.