Properties of BaTiO3 confined in opal matrices — lattice packings of nanospheres silica dioxide

Abstract

Using the sol-gel technique, BaTiO3 was embedded in opal matrices that are the lattice packings of silica dioxide nanospheres for the first time. The room-temperature IR and Raman spectra clearly show characteristic vibrational modes of the ferroelectrically distorted TiO6 octahedra without any long-range order. Raman spectra bring evidence of a diffuse ferroelectric phase transition in the opal-BaTiO3 composite.