Structure and properties of nanocrystalline BaHfO 3 synthesized by an auto-igniting single step combustion technique

Abstract

High quality nanoparticles of barium hafnate have been synthesized using an auto-ignition modified combustion technique. The nanoparticles thus obtained have been characterized by powder X-ray diffraction, thermo gravimetric analysis, differential thermal analysis, Fourier transform infrared spectroscopy and transmission electron microscopy. The XRD studies have shown that the as-prepared BaHfO 3 powders are phase pure. The particle size of the as-prepared powder was in the range 20–50 nm. The nanopowder could be sintered to 95% of the theoretical density at 1650 °C for 2 h. The ultrafine cuboidal nature of nanopowders with small degree of agglomeration improved the sinterability at relatively lower temperature and time. The microstructure of the sintered surface was examined using scanning electron microscopy. The dielectric constant ( ɛ r ) of 30.8 and loss factor (tan δ) of 2.3 × 10 −3 were obtained at 1 MHz.