Center for Materials for Information Technology, The University of Alabama, Tuscaloosa, Alabama 35487, USA.
J Am Chem Soc. 2011 Dec 28;133(51):20716-9. doi: 10.1021/ja209575w. Epub 2011 Dec 2.
Nanocrystals and nanoclusters of the room-temperature magnetic spinel CuCr(2)S(4) have been synthesized using a facile solution-based method. The synthesis involves hot injection of an excess of 1-dodecanethiol (1-DDT) into a boiling coordinating solvent containing CuCl(2) and CrCl(3)·6H(2)O. Using octadecylamine (ODA) as a solvent yields cube-shaped nanocrystals with an average size of 20 ± 2 nm, while with oleylamine (OLA), nanoclusters with an average size of 31 ± 2.5 nm are obtained. In both cases, powder X-ray diffraction patterns confirmed the formation of the pure spinel phase without any impurities. While the synthesized powders are superparamagnetic near room temperature, they exhibit ferromagnetic behavior at lower temperatures, with magnetization (M(S)) values of 30 emu/g (1.63 μ(B)/f.u.) and 33 emu/g (1.79 μ(B)/f.u.) for the ODA- and OLA-capped nanocrystals and nanoclusters, respectively, at 5 K.
室温磁性尖晶石 CuCr(2)S(4)的纳米晶和纳米团簇已通过一种简单的溶液法合成。该合成方法涉及将过量的 1-十二硫醇（1-DDT）热注入沸腾的配位溶剂中，该溶剂含有 CuCl(2)和 CrCl(3)·6H(2)O。使用十八胺（ODA）作为溶剂可得到平均尺寸为 20 ± 2nm 的立方体形纳米晶，而使用油胺（OLA）则可得到平均尺寸为 31 ± 2.5nm 的纳米团簇。在这两种情况下，粉末 X 射线衍射图谱均证实了纯尖晶石相的形成，没有任何杂质。尽管合成的粉末在室温附近呈超顺磁性，但在较低温度下表现出铁磁性，ODA 和 OLA 封端的纳米晶和纳米团簇的磁化强度（M(S)）值分别为 30 emu/g（1.63 μ(B)/f.u.）和 33 emu/g（1.79 μ(B)/f.u.），在 5 K 时。
