Centre for Nano Research (CNR), Tumkur University, Tumkur 572 103, India; Department of Physics, RV College of Engineering, Bangalore 560 091, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2014 Jan 24;118:847-51. doi: 10.1016/j.saa.2013.08.050. Epub 2013 Sep 21.
Nanoparticles of magnesium oxide (MgO) have been prepared by low temperature solution combustion and hydrothermal method respectively. Powder X-ray diffraction (PXRD) patterns of MgO samples prepared by both the methods show cubic phase. The Scanning Electron Microscopy (SEM) studies reveal, the combustion derived product show highly porous, foamy and fluffy in nature than hydrothermally derived sample. The optical absorption studies of MgO show surface defects in the range 250-300 nm. The absorption peak at ∼290 nm might be due to F-centre. Photoluminescence (PL) studies were carried upon exciting at 290 nm. The sample prepared via combustion method show broad emission peak centred at ∼395 nm in the bluish-violet (3.14 eV) region. However, in hydrothermal prepared sample show the emission peaks at 395 and 475 nm. These emission peaks were due to surface defects present in the sample since nanoparticles exhibits large surface to volume ratio and quantum confinement effect.
分别采用低温溶液燃烧法和水热法制备了氧化镁(MgO)纳米粒子。两种方法制备的 MgO 样品的粉末 X 射线衍射(PXRD)图谱均显示为立方相。扫描电子显微镜(SEM)研究表明,燃烧法得到的产物比水热法得到的产物具有更高的多孔性、泡沫状和蓬松状。MgO 的光吸收研究表明,在 250-300nm 范围内存在表面缺陷。在 ∼290nm 处的吸收峰可能是由于 F 中心。在 290nm 处激发进行了光致发光(PL)研究。通过燃烧法制备的样品在蓝紫色(3.14eV)区域中显示出中心位于 ∼395nm 的宽发射峰。然而,在水热法制备的样品中观察到 395nm 和 475nm 的发射峰。这些发射峰归因于样品中存在的表面缺陷,因为纳米粒子具有较大的比表面积和量子限制效应。