Influence of B site-cations on phase transition, magnetic switching and band-gap modulation in Pb(B′_0.5B″_0.5)O₃–Pb(Zr_0.53Ti_0.47)O₃ ceramics

The xPb(Fe_0.5Nb_0.5)O₃–(1-x)Pb(Zr_0.53Ti_0.47)O₃ and yPb(Fe_0.5Ta_0.5)O₃–(1-y)Pb(Zr_0.53Ti_0.47)O₃ multiferroic ceramics synthesized by a solid state reaction method have been investigated by means of structural characterizations, optical and magnetic measurements. X-ray diffraction (XRD) and Raman scattering analyses show that all the samples have the perovskite structure, but exhibit different phase transition behaviors resulting from the influence of B-cations. The internal lattice strain of the ceramics is estimated from XRD data by Williamson-Hall analysis method. The optical measurement indicates that the modification of optical properties can be achieved by manipulating the composition accurately in these perovskite oxides. Pb(Fe_0.5Nb_0.5)O₃ or Pb(Fe_0.5Ta_0.5)O₃ doping reduces the band-gap of Pb(Zr_0.53Ti_0.47)O₃ from 3.32eV to 2.51 eV. Furthermore, the different magnetic behaviors of the two compounds are observed, which mainly stem from the effects of nonmagnetic Nb and Ta cations on the interaction strength among the magnetic Fe ions. These results are helpful for a deeper understanding of structural, optical and magnetic properties and show the potential role, such materials can play, in multiferroic applications and solar energy devices.