MgO nanostructures at different annealing temperatures for d0 ferromagnetism

Abstract

Present study is based on the facile development of magnesium oxide (MgO) nanostructures at different annealing temperatures (300°C, 500°C, 700°C & 900°C) for d0 ferromagnetism. The developed MgO nanostructures were characterized for structural, morphological and magnetic properties using versatile techniques. X-ray diffraction (XRD) results revealed the formation of hexagonal phase corresponding to Mg(OH)2 at 300 °C which further transforms to cubic phase of MgO nanostructures at higher temperatures. SEM image showed the variation in morphology with temperature from nanoflakes to flowers and then hexagonal sheets. It has been found that saturation magnetisation increases with temperature. The concept of d0 ferromagnetism is understood on the basis of defects which were confirmed from XPS studies. Further, electron paramagnetic resonance (EPR) measurements were also performed to understand the paramagnetic ions and exchange interaction of spins which support the defects present in the material.