In this paper structural, electric, magnetic, and Mössbauer spectroscopy studies were conducted in (x)BiFeO₃–(1-x)BaTiO₃, 0.9 ≥ x ≥ 0.3, solid solutions. X-ray diffraction and Rietveld refinement studies indicated the formation of single-phased materials crystallized in a distorted perovskite structure with the coexistence of rhombohedral and monoclinic symmetries. Room temperature ferroelectric hysteresis loops showed that the electric polarization increases with the increase of the BaTiO₃ content due to the singular structural evolution of the studied solid solutions. All samples presented weak ferromagnetic ordering, which indicates that the BaTiO₃ substitution in the BiFeO₃ matrix released the latent magnetization. Mössbauer studies revealed a magnetic spectral signature corresponding to ordered Fe³⁺ ions, and a decrease of the magnetic hyperfine magnetic fields with the increase of the BaTiO₃ content. The composition 0.3BiFeO₃–0.7BaTiO₃ presented a spectral signature corresponding to a paramagnetic behavior, which strongly suggests that the observed magnetization in this sample is due to the Ti³⁺ ions.

This work presents the structural and spectroscopic characterization of transparent lead lanthanum zirconate titanate ceramics doped with ${\mathrm{Nd}}^{\text{3+}},$ ${\mathrm{Er}}^{\text{3+}},$ or ${\mathrm{Yb}}^{\text{3+}}$ ions. High optical quality samples presenting the perovskite structure were prepared through a mixed oxides method followed by conventional sintering or uniaxial hot pressing. Absorption and luminescence spectra were measured, and radiative emission parameters were calculated for ${\mathrm{Nd}}^{\text{3+}}-$ and ${\mathrm{Er}}^{\text{3+}}$ -doped samples. The results indicate the potential of these polycrystalline host–ion combinations for the construction of diode-pumped lasers in the near-infrared region.