Kinetically Controlled Synthesis of Hexagonally Close-Packed Cobalt Nanorods with High Magnetic Coercivity
Kinetically Controlled Synthesis of Hexagonally Close-Packed Cobalt Nanorods with High Magnetic Coercivity
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DOI：
10.1002/adfm.200800822
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发表时间：
2009-06-23
影响因子：
19
通讯作者：
Viau, Guillaume
中科院分区：
文献类型：
--
作者：
Soumare, Yaghoub;Garcia, Cecile;Viau, Guillaume
用一种快速、简单、无固相模板的方法将Co(II)的羧酸盐还原到1，2-丁二醇中，得到了高质量的单分散金属钴纳米棒。在这个多元醇过程中，颗粒形状可以通过生长速度来控制，这取决于三个参数：1)羧酸钴的性质，ii)温度梯度，以及iii)介质的碱度。六方密排相中的钴有利于各向异性粒子的生长。钴纳米棒的磁性测量表明，它们在室温下是铁磁性的。它们在140K时具有非常高的矫直力，为9.0Koe，远远高于用固体模板制备的线材。这可以归因于它们的平均直径小和结晶度高。
High-quality monodisperse metallic cobalt nanorods are obtained by the reduction of carboxylate salts of Co(II) in 1,2-butanediol using a rapid, simple, and solid-template-free procedure. In this polyol process, particle shape can be controlled via the growth rate, which depends on three parameters: 1) the nature of the cobalt carboxylate, ii) the temperature ramp, and iii) the basicity of the medium. Cobalt in the hexagonally close-packed phase favored the growth of anisotropic particles. Magnetic measurements of the cobalt nanorods indicate they are ferromagnetic at room temperature. They have a very high coercivity of 9.0 kOe at 140 K, much higher than that observed for wires prepared with solid templates. This can be attributed their small mean diameter and high crystallinity.