Characterizations of diverse mole of pure and Ni-doped α-Fe2O3 synthesized nanoparticles through chemical precipitation route.
Characterizations of diverse mole of pure and Ni-doped α-Fe2O3 synthesized nanoparticles through chemical precipitation route.
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DOI：
10.1016/j.saa.2014.02.136
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发表时间：
2014-07
期刊：
影响因子：
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通讯作者：
S. Sivakumar;D. Anusuya;Chandra Prasad Khatiwada;J. Sivasubramanian;A. Venkatesan;P. Soundhirarajan
中科院分区：
文献类型：
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作者：
S. Sivakumar;D. Anusuya;Chandra Prasad Khatiwada;J. Sivasubramanian;A. Venkatesan;P. Soundhirarajan
本研究采用化学沉淀法制备了纯α-Fe_2O_3（赤铁矿）和Ni掺杂α-Fe_2O_3（赤铁矿）纳米粒子。采用X射线衍射（X-RD）、傅里叶变换红外光谱（FTIR）、紫外-可见漫反射光谱（UV-Vis DRS）、振动样品磁强计（VSM）和扫描电子显微镜（SEM）对合成产物进行了表征。利用Debye-Scherrer方程计算了α-Fe 2 O3纳米粒子的平均粒径，确定为31 nm。SEM照片显示了合成样品的表面形貌、结构和颗粒分布。UV-Vis漫反射光谱表明，纯α-Fe 2 O3和Ni掺杂α-Fe 2 O3的间接带隙和直接带隙分别从1.9847和2.0503降低到1.52 eV和1.76 eV。这一结果表明，掺杂剂提高了铁氧化物纳米颗粒的半导体性能，其程度与其在α-Fe 2 O3中的镍掺杂成正比。利用振动样品磁强计（VSM）研究了掺杂前后样品的磁性能，发现掺杂前后样品在室温下均表现出饱和磁滞回线，表明掺杂前后样品具有弱的铁磁性。此外，从Ni掺杂的磁化曲线可以看出，这是由于样品的饱和磁化强度增加，磁化率降低。因此，本研究表明，Ni掺杂降低了α-Fe 2 O3纳米粒子的带隙能量和矫顽场。
In the present study, an attempt has been made for characterization and synthesis of pure and Ni-doped α-Fe2O3(hematite) nanoparticles by chemical precipitation method. The synthesized products have been studied by X-ray diffraction (X-RD), Fourier transform infrared (FTIR) spectroscopy, UV–Vis diffuse reflectance spectroscopy (UV–Vis DRS), vibrating sample magnetometer (VSM) and scanning electron microscopy (SEM) techniques. The estimated average diameter of α-Fe2O3nanoparticles were calculated by using the Debye–Scherrer equation and established as 31 nm. SEM micrographs showed the surface morphology as well as structures and particles distributions of synthesized samples. The UV–Vis DRS showed the indirect and direct band gap energies of pure and Ni-doped α-Fe2O3, these were reduced from 1.9847 to 1.52 eV and 2.0503 to 1.76 eV respectively. This result suggested the dopant enhanced the semiconducting behavior of iron oxide nanoparticles to an extent proportional to its nickel doped in the α-Fe2O3. Further, the magnetic properties of the pure and doped samples were investigated by vibrating sample magnetometer (VSM) and evaluated the information of pure and doped samples exhibited saturated hysteresis loop at room temperature, which is indicating that the weak ferromagnetism in nature of our synthesized samples. In addition, it has been found from the magnetization hysteresis curves of Ni-doping, resulting from increased the saturation of magnetization and reduced the coercivity of used samples. Therefore, the present study showed the reduction in band gap energies and coercive field for α-Fe2O3nanoparticles due to nickel doped.