Magnetodielectric effect of CuO grown within highly ordered two dimensional mesoporous silica template SBA 15

Abstract

A two component, inhomogeneous medium can produce magnetodielectric (MD) effect without any magnetoelectric coupling. Here, we have prepared an inhomogeneous material by growing CuO within two dimensional mesostructures of silica template SBA-15 by a single step method. The (CuO)_x-(SBA-15)_1−x nanocomposites with different weight percentages (x = 0.2, 0.35, and 0.5) were characterized by small angle x-ray diffraction study and transmission electron microscopy. Both studies confirmed the highly ordered hexagonal mesostructure for CuO(20) where 20 is the weight percentage of CuO in nanocomposite (i.e., x = 0.2). The mesostructure was destroyed on increasing the percentage of CuO incorporated. The nanocomposites exhibited magnetodielectric effect with dielectric constant change of 4.4% and 3% for CuO(20) and CuO(35), respectively, at 1.8 T magnetic field. This effect was explained on the basis of a two dimensional inhomogeneous two component composite model. No such effect occurs in CuO(50) due to total disappearance of the ordered mesostructure.