Anomalous magnetic behavior in FePt nanoparticles chemically synthesized with polymer protective agent
Anomalous magnetic behavior in FePt nanoparticles chemically synthesized with polymer protective agent
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DOI：
10.1016/j.physb.2009.03.048
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发表时间：
2009-07-01
影响因子：
2.8
通讯作者：
Toshima, Naoki
中科院分区：
文献类型：
--
作者：
Iwamoto, Takashi;Kitamoto, Yoshitaka;Toshima, Naoki
采用化学方法合成了以聚（n -乙烯基-2-吡咯烷酮）（PVP）为保护剂的FePt纳米颗粒。在不同反应温度下合成的FePt纳米颗粒，其矫顽力在20 K以下的低温下与直径的关系表现出反常的磁性行为；矫顽力随粒径的减小而增大，不同于热波动效应所解释的矫顽力随粒径的增大而增大。我们讨论了由于PVP和FePt纳米颗粒表面之间的配位键导致的与表面效应相关的异常磁性行为。(C) 2009 Elsevier B.V.版权所有
FePt nanoparticles protected by poly(N-vinyl-2-pyrrolidone) (PVP) as a protective agent are synthesized by a chemical route. Diameter dependence of coercivity at low temperatures below similar to 20 K for the FePt nanoparticles synthesized at various reaction temperatures exhibits an anomalous magnetic behavior; the coercivity increases with decreasing particle-diameter, which is different from a particle-size dependence of coercivity explained by thermal fluctuation effect. We discuss the anomalous magnetic behaviors associating with a surface effect due to coordinate bonds between PVP and the surface of the FePt nanoparticles. (C) 2009 Elsevier B.V. All rights reserved.