Department of Chemistry, Brown University , Providence, Rhode Island 02912, United States.
Nano Lett. 2014 Jun 11;14(6):3395-9. doi: 10.1021/nl500904a. Epub 2014 May 9.
We report a facile synthesis of monodisperse ferrimagnetic Co(x)Fe(3-x)O4 nanocubes (NCs) through thermal decomposition of Fe(acac)3 and Co(acac)2 (acac = acetylacetonate) in the presence of oleic acid and sodium oleate. The sizes of the NCs are tuned from 10 to 60 nm, and their composition is optimized at x = 0.6 to show strong ferrimagnetism with the 20 nm Co0.6Fe2.4O4 NCs showing a room temperature Hc of 1930 Oe. The ferrimagnetic NCs are self-assembled at the water-air interface into a large-area (in square centimeter) monolayer array with a high packing density and (100) texture. The 20 nm NC array can be recorded at linear densities ranging from 254 to 31 kfci (thousand flux changes per inch). The work demonstrates the great potential of solution-phase synthesis and self-assembly of magnetic array for magnetic recording applications.
我们通过热分解 Fe(acac)3 和 Co(acac)2（acac = 乙酰丙酮酸盐），在油酸和油酸钠的存在下，简便地合成了单分散的铁磁性 Co(x)Fe(3-x)O4 纳米立方体形貌（NCs）。NCs 的尺寸从 10 纳米调至 60 纳米，其组成在 x = 0.6 时达到最佳，显示出强的亚铁磁性，20nm Co0.6Fe2.4O4 NCs 在室温下的矫顽力为 1930 Oe。铁磁性 NCs 在水-空气界面处自组装成大面积（平方厘米级）单层排列，具有高密度和（100）织构。20nm NC 阵列可以在 254 至 31 kfci（每英寸千通量变化）的线性密度下记录。这项工作展示了溶液相合成和磁性阵列自组装在磁记录应用中的巨大潜力。
