Influence of the thermal treatment on structure and dielectric properties of nanostructured BaTiO

Influence of thermal treatment on the crystalline structure, FTIR spectra and dielectric properties of initially cubic perovskite BaTiO3 nanoparticles with the average size of 100 nm was studied. It is found that the thermal treatment leads to the formation of ferroelectric tetragonal phase. Experimental results show that an appearance of ferroelectricity in the nanostructured BaTiO3 and its dielectric permittivity (ε) variation is caused by the decrease of lattice defects concentration owing to thermal annealing. Such defects lead, in particular, to the wide thermal hysteresis of ε observed at cyclic temperature variation in the vicinity of the Curie temperature (TC) and specific dependence of TC on d.c. field