CAJ | 학술논문

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 moJL/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.
위료연구일유고철양체납미관진렬적자학성질,응용양화려모판구유적약속작용화모세관작용,결합용효응효기술합성료고철양체납미관진렬.재140℃조건하,통과포함Fe(AO)3화Co(AO)2(물질적량지비위2:1)적저몽산화을이순혼합용액(물질적량지비위1:4)지화반응득도용효.장양화려모판침입용효궤차후취출,취출충만용효적양화려모판,재대기기분중,이0.6℃/min～5℃/min적승온속도장양품유실온승온지500℃,보온8 h.결과표명,재공제Fe3+리자농도적조건하야가이합성고철양체납미선(Fe3+리자농도대우1 moL/L)화"죽절"형납미관(Fe3+리자농도개우0.5 mol/L-1.0 moJL/L),단중점진행료기납미관진렬(Fe3+리자농도소우0.5 moL/L)합성화자학성능측시.투사전자현미경(TEM)、고분변전경(HRTEM)적관찰이급분말X광연사(XRD)측시결과표명납미관조성위다정결구.납미관적직경취결우양화려모판적공경,대약위200 nm,기장도약궤개미미.응용양품진동자강계대양품자성진행료표정,결과표명납미관진렬미표현출방향특성,교완력수착승온속솔적강저이승고,재0.6℃/min적승온속솔시,교완력체도최고적1 445 kOe,간단토론료기형성원인.
On the basis of the confinement effect and capillary force of nano-ehannel alumina template (NCAT) ,magnetic cobalt ferrite nanotube arrays were synthesized in sol-gel process and their magnetic properties were studied. The sol was formed by esterification of the mixture solution of citric acid and eth-ylene glycol with a molar ratio of 1:4 containing the metal precursor salts Fe (AO)3 and Co (AO)2 with the molar ratio of 2:1 at 140 ℃. NCAT was dipped into the sol several times and taken out, filled with v sol, which was annealed at 500℃ for 8 h in the open air. The temperature was raised from room temper-ature to 500 ℃ with the heating rate of.0.6 ℃/min-5.0 ℃/min. The focus of the study was on the fab-rication and magnetic properties of cobalt ferrite nanotube arrays (with concentration of Fe3 less than 0.5 tool/L), although experimental results indicate that cobalt ferrite nanowires (with concentration of anode ions Fe3+ more than 1 mol/L) and "bamboo" type nanotube arrays (with concentration of anode ions Fe3+ ranging from 0.5 mol/L to 1.0 tool/L) could be synthesized through control of Fe3+ concentra-tion. Transmission electron microscope (TEM), high-resolution transmission electron microscope (HR-TEM) images and X-ray diffraction (XRD) pattern show that the nanotubes were in the polycrystallinephase, with the length of several microns and the diameter of about 200 nm, which was dependent on the size of NCAT. Vibration magnetometer was used to investigate the magnetic properties of the sample ofcobalt ferrite nanotube arrays, which indicates that the arrays of nanotube do not show a preferential mag-netic orientation, and the coercivity increase with the decrease of heating rate and reach a maximum of 1 445 kOe at the heating rate of 0.6 ℃/min, the reasons for which were discussed briefly.