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为了研究一维钴铁氧体纳米管阵列的磁学性质,应用氧化铝模板具有的约束作用和毛细管作用,结合溶胶凝胶技术合成了钴铁氧体纳米管阵列.在140℃条件下,通过包含Fe(AO)3和Co(AO)2(物质的量之比为2∶1)的柠檬酸和乙二醇混合溶液(物质的量之比为1∶4)酯化反应得到溶胶.将氧化铝模板浸入溶胶几次后取出,取出充满溶胶的氧化铝模板,在大气气氛中,以0.6℃/min～5℃/min的升温速度将样品由室温升温至500℃,保温8 h.结果表明,在控制Fe3+离子浓度的条件下也可以合成钴铁氧体纳米线(Fe3+离子浓度大于1 mol/L)和“竹节”型纳米管(Fe3+离子浓度介于0.5 mol/L～1.0 mol/L),但重点进行了其纳米管阵列(Fe3+离子浓度小于0.5 mol/L)合成和磁学性能测试.透射电子显微镜(TEM)、高分辨电镜(HRTEM)的观察以及粉末X光衍射(XRD)测试结果表明纳米管组成为多晶结构.纳米管的直径取决于氧化铝模板的孔径,大约为200 nm,其长度约几个微米.应用样品振动磁强计对样品磁性进行了表征,结果表明纳米管阵列未表现出方向特性,矫顽力随着升温速率的降低而升高,在0.6℃/min的升温速率时,矫顽力达到最高的1 445 kOe,简单讨论了其形成原因.
In order to study the magnetic properties of one-dimensional cobalt ferrite nanotube arrays, a cobalt ferrite nanotube array was synthesized by using the constraint and capillary action of alumina templates combined with sol-gel technique. At 140 ℃, A mixed solution of citric acid and ethylene glycol containing a molar ratio of 1: 4 of Fe (AO) 3 and Co (AO) 2 (in a ratio of 2: 1) was esterified to obtain a sol. After the alumina template was immersed in the sol for several times, it was taken out and the alumina-filled template was taken out. The sample was heated from room temperature to 500 ° C in an air atmosphere at a heating rate of 0.6 ° C / min to 5 ° C / min for 8 h. The results show that cobalt ferrite nanowires (Fe3 +> 1 mol / L) and “bamboo” nanotubes can be synthesized under the control of Fe3 + concentration (Fe3 + concentration is between 0.5 mol / L ~ 1.0 mol / L), but the synthesis and magnetic properties of the nanotube arrays (Fe3 + ion concentration less than 0.5 mol / L) were mainly investigated by transmission electron microscopy (TEM), high resolution electron microscopy (HRTEM) The results of the diffraction (XRD) test showed that the nanotube has a polycrystalline structure, and the diameter of the nanotube depends on the size of the alumina template Diameter of about 200 nm, the length of about a few microns.The sample magnetometer was characterized by a sample vibrating magnetometer, the results showed that the nanotube array showed no directional characteristics, the coercive force increased with the heating rate decreased At a heating rate of 0.6 ℃ / min, the highest coercivity of 1445 kOe was obtained, and its formation was briefly discussed.