The investigations of phase transitions in the (1-x)PbZrO3-xBiFeO3 nanocrystals using differential scanning calorimetry and Raman spectroscopy

Abstract

Polycrystalline powders of PbZrO3, 0.98PbZrO3–0.02BiFeO3, and 0.96PbZrO3–0.04BiFeO3 were synthesised by means of a molten salt synthesis route. Their structure and morphology were studied using X-ray powder diffraction and scanning electron microscopy, respectively. The frequencies of the Raman lines were analysed and discussed in terms of the sequence of structural phase transitions. The measurements revealed the existence of a new intermediate phase observed below the Curie point (Tc) and an additional temperature anomaly above Tc, most likely connected with magnetic transition originating from BiFeO3 contribution. The addition of multiferroic BiFeO3 into the structure of antiferroelectric PbZrO3 suggests that the obtained solid solutions form multiferroic systems even at low BiFeO3 content. The Raman measurements were supplemented by dielectric studies and differential scanning calorimetry measurements. An excellent agreement for transition temperatures obtained by means of these three techniques suggests that BiFeO3 is uniformly distributed in the synthesised powder materials.