Structural, electrical and dielectric properties of spinel type MgAl2O4 nanocrystalline ceramic particles synthesized by the gel-combustion method

摘要

Nanocrystalline spinel type magnesium aluminate (MgAl2O4) ceramic material was synthesized by gel-combustion method. The structural, microstructural, morphology, electrical and dielectric properties of the prepared spinel type MgAl2O4 ceramic material were studied by different techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), surface area analyzer (BET) and impedance spectroscopy. The X-ray diffraction pattern and PR spectrum of magnesium aluminate material confirm the formation of impurity free nanocrystalline phase with spinel structure. The specific surface area calculated from the 1/[W((P-o/P)-1)] vs relative pressure (P/P-o) plot of the annealed MgAl2O4 powder is found to be 162.704 m(2)/g. The temperature dependent conductivity of nanocrystalline MgAl2O4 pellet was studied and the conductivity of nanocrystalline MgAl2O4 pellet at 573 K is found to be 4.9213 x 10(-13) S cm(-1). The activation energies were evaluated from log sigma T vs 1000/T plot of the observed two different temperature dependent conductivity regions of the nanocrystalline MgAl2O4 sample and are found to be E-1=0.1828 eV (< 503 K) and E-2 = 0.8791 eV (> 503 K). (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.