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.