Synthesis of nanocrystalline magnesium titanate by an auto-igniting combustion technique and its structural, spectroscopic and dielectric properties

Abstract

Nanocrystalline magnesium titanate was synthesized through an auto-ignited combustion method. The phase purity of the powder was examined using X-ray diffraction, thermo gravimetric analysis, differential thermal analysis, Fourier transform infrared spectroscopy and Raman spectroscopy. The transmission electron microscopy study showed that the particle size of the as-prepared powder was in between 20 and 40 nm. The nanopowder could be sintered to 98% of the theoretical density at 1200 °C for 3 h. The microstructure of the sintered surface was examined using scanning electron microscopy. The dielectric constant ( ɛ r ) of 16.7 and loss factor (tan δ) of the order of 10 −4 were obtained at 5 MHz when measured using LCR meter. The quality factor ( Q u × f) 73,700 and temperature coefficient of resonant frequency ( τ f ) −44.3 ppm/°C, at 6.5 GHz are the best reported values for sintered pellets obtained from phase pure nanocrystalline MgTiO 3 powder.