Magnetic properties of interacting CoPt nanoparticles synthesized through polyol process
Magnetic properties of interacting CoPt nanoparticles synthesized through polyol process
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DOI：
10.1016/j.matchemphys.2015.01.044
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发表时间：
2015-03
影响因子：
4.6
通讯作者：
Prakash Karipoth;R. J. Joseyphus
中科院分区：
文献类型：
--
作者：
Prakash Karipoth;R. J. Joseyphus
Co40Pt60nanoparticles with an average particle size of 3.9 nm were prepared by polyol pathway without incorporating any capping agents or surfactants. The as-prepared nanoparticles were superparamagnetic having disordered A1-face centered cubic structure, which transforms to face centered tetragonal (L10) phase on heat treatment, without the requirement of a reducing gas. The Curie temperature of the Co40Pt60nanoparticles was determined to be 482 °C from the thermomagnetic analysis. Coercivity upto 7 kOe was obtained on annealing at a relatively lower temperature of 600 °C. Anomalous variation in coercivity has been observed with annealing. Annealing temperature dependent two phase behavior was studied by δM measurements. The CoPt samples exhibited dipolar coupling on annealing up to 700 °C and strong exchange coupling was evident with further increase in annealing temperature.
