Synthesis, self-assembly, and magnetic properties of FexCoyPt100-x-y nanoparticles
Synthesis, self-assembly, and magnetic properties of FexCoyPt100-x-y nanoparticles
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DOI：
10.1021/nl015649w
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发表时间：
2002-03-01
期刊：
影响因子：
10.8
通讯作者：
Nikles, DE
中科院分区：
文献类型：
--
作者：
Chen, M;Nikles, DE
通过同时还原乙酰丙酮钴和乙酰丙酮铂以及五羰基铁的热分解制备了FexCoyPt100-x-y合金纳米颗粒。颗粒中铁、钴和铂的相对量取决于加入到反应中的铁、钴和铂的量。所制备的颗粒具有超顺磁性并具有扭曲的面心立方结构。平均粒径为3.5 nm，尺寸分布非常窄。这些颗粒可以分散在碳氢化合物溶剂中，并在碳涂层的铜 TEM 网格上形成由六方密堆积颗粒组成的薄膜。这些薄膜溅射涂有无定形碳，然后在 550 至 700 摄氏度的温度下退火，将颗粒转变为四方 (L1(0)) 相。退火薄膜的矫顽力随着退火温度的升高而增加。对于具有相似程度的四方相转变的薄膜，增加钴含量会降低薄膜的矫顽力。
FexCoyPt100-x-y alloy nanoparticles were prepared by the simultaneous reduction of cobalt acetylacetonate and platinum acetylacetonate and the thermal decomposition of iron pentacarbonyl. The relative amounts of iron, cobalt, and platinum in the particles depended on the amount of iron, cobalt and platinum charged to the reaction. As prepared, the particles were superparamagnetic and had a distorted fcc structure. The average particle diameter was 3.5 nm and the size distribution was very narrow. The particles could be dispersed in hydrocarbon solvents and formed films consisting of hexagonal close-packed particles on carbon-coated copper TEM grids. The films were sputter coated with amorphous carbon and then annealed at temperatures ranging from 550 to 700 degreesC to transform the particles to the tetragonal (L1(0)) phase. The coercivity of the annealed films increased with increasing annealing temperature. For films with a similar degree of transformation to the tetragonal phase, increasing the cobalt content decreased the coercivity of the films.