Basith N Mohamed, Vijaya J Judith, Kennedy L John, Bououdina M, Hussain Shamima
J Nanosci Nanotechnol. 2014 Mar;14(3):2577-83. doi: 10.1166/jnn.2014.8514.
In this study, pure and Co-doped CuO nanostructures (0.5, 1.0, 1.5, and 2.0 at wt% of Co) were synthesized by microwave combustion method. The prepared samples were characterized by X-ray diffraction (XRD), high resolution scanning electron microscopy (HR-SEM), energy dispersive X-ray analysis (EDX), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy and vibrating sample magnetometry (VSM). Powder X-ray diffraction patterns refined by the Rietveld method indicated the formation of single-phase monoclinic structure. The surface morphology and elemental analysis of Co-doped CuO nanostructures were studied by using HR-SEM and EDX. Interestingly, the morphology was found to change considerably from nanoflowers to nanoplates then to nanoparticles with the variation of Co concentration. The optical band gap calculated using DRS was found to be 2.1 eV for pure CuO and increases up to 3.4 eV with increasing cobalt content. Photoluminescence measurements also confirm these results. The magnetic measurements indicated that the obtained nanostructures were ferromagnetic at room temperature with an optimum value of saturation magnetization at 1.0 wt.% of Co-doped CuO, i.e., 970 micro emu/g.
在本研究中，通过微波燃烧法合成了纯的和钴掺杂的CuO纳米结构（钴的掺杂量为0.5、1.0、1.5和2.0原子重量百分比）。通过X射线衍射（XRD）、高分辨率扫描电子显微镜（HR-SEM）、能量色散X射线分析（EDX）、漫反射光谱（DRS）、光致发光（PL）光谱和振动样品磁强计（VSM）对制备的样品进行了表征。用Rietveld方法精修的粉末X射线衍射图谱表明形成了单相单斜结构。利用HR-SEM和EDX研究了钴掺杂CuO纳米结构的表面形貌和元素分析。有趣的是，随着钴浓度的变化，形貌从纳米花显著变化为纳米板，然后变为纳米颗粒。利用DRS计算得出，纯CuO的光学带隙为2.1 eV，随着钴含量的增加，光学带隙增加到3.4 eV。光致发光测量也证实了这些结果。磁性测量表明，所获得的纳米结构在室温下是铁磁性的，在钴掺杂量为1.0重量百分比的CuO时，饱和磁化强度的最佳值为970微emu/g。
