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The xBiFeO3–(1–x)PbZr0.9Ti0.1O3 composites synthesized by the solid-phase reaction were characterized using complex methods to determine their structure and physical properties. According to the results of X-ray diffraction analysis, it was found that the synthesized composites have a rhombohedral perovskite structure with the space symmetry group R3с, and there are no impurities or second phases present in either the ferrite or ferroelectric phases. According to the results of impedance spectroscopy, it was found that the nature of the relaxation in the composites is non-Debye, suggesting a complex conduction mechanism involving multiple relaxation processes. With an increasing proportion of ferroelectric PbZr0.9Ti0.1O3 (PZT) phase, the composites exhibit dual-arc behavior in the Cole-Cole diagrams obtained from the impedance spectroscopy measurements. The dual-arc behavior shows the contribution of both the bulk (grain) and grain boundary to the conduction mechanism in the temperature range of 160–230 °C. The dynamics of the crystal lattice in the composites were studied using optical and FTIR spectroscopy. The magnetization curves M(H) of the composites are characterized by weak ferromagnetism, which is due to the substitution of (Ti/Zr)4+ by Fe3+ in the crystal lattice. This substitution leads to structural distortions and the appearance of ferromagnetic ordering in the composite materials. [ABSTRACT FROM AUTHOR]

In this work, the structural phase state and physical properties of YbMn1-xFexO3 (hereinafter YbMF) ceramics in the range of x = 0.0–1.0 with a concentration step Δx = 0.1 were studied by complex methods. X-ray diffraction revealed that the YbMF compositions in the range of x = 0.1–0.5 were hexagonal (H) phase solid solutions. In the concentration range of x = 0.6–0.8, the hexagonal and orthorhombic (O) systems coexist, and the unit cell parameters of these phases rise with increasing x. The study of the lattice parameters, bond lengths, bond angles and the main parameters of the magnetic hysteresis loop of the H-phase revealed the presence of a singular point x = 0.5 in the concentration range, where extrema of the corresponding parameters were observed. By analyzing the Cole–Cole plots for the electric modulus M*(ω), a conclusion was drawn about the thermally activated nature of the dielectric relaxation for each composition with a single relaxation time τ. The magnetodielectric MD(ω) and magnetoresistive MR(ω) coefficients measured in crossed and parallel fields E and H show high values, which reach 1.6% and 50%, respectively, depending on the frequency of the measuring field. [ABSTRACT FROM AUTHOR]

In this work, the influence of simultaneous action of high pressure and shear deformation (mechanical activation) on the physical properties of synthesized YbFeO3 was studied using complex methods. The formation of crystalline structures of YbFeO3 powders with different concentrations of structural defects was carried out using Bridgman anvils. It was found that during mechanical activation, the tilting angles of FeO6 oxygen octahedra change within the range θ = 12.69–28.45°. Using X-ray diffraction, it was established that the linear unit cell parameters a, b and c change in a consistent manner with changing mechanical activation pressure, while the space-group symmetry D 2 h 16 –Pbnm is preserved. The sizes of the coherent scattering regions (D) decrease by more than 90% at the maximum mechanical activation pressure (1200 MPa). It was found that the mechanical activation pressures of YbFeO3 have a threshold value (800 MPa), above which the dislocation density decreases. According to the results of impedance spectroscopy, the nature of relaxation was found to be non-Debye and the activation energy increased from 0.649 eV for the starting sample to 1.395 eV for the sample mechanically activated sample at 1 GPa. The magnetization curves M(H) were described using the law of approach to magnetic saturation (LAS), and the critical crystallite size (Dcr) was determined to be 50 nm, at which the maximum Hc is observed. The behaviors of the spectroscopic splitting factor (g) and half-width (ΔH) of the electron paramagnetic resonance (EPR) spectrum are analogous to Hc and Mr, however, the maximum ΔH is observed in the range of 50–105 nm, and the g-factor reaches its maximum at particle sizes of 105 nm. [ABSTRACT FROM AUTHOR]

In this work, the influence of simultaneous action of high pressure and shear deformation (mechanical activation) on the physical properties of synthesized YbFeO3 was studied using complex methods. The formation of crystalline structures of YbFeO3 powders with different concentrations of structural defects was carried out using Bridgman anvils. It was found that during mechanical activation, the tilting angles of FeO6 oxygen octahedra change within the range θ = 12.69–28.45°. Using X-ray diffraction, it was established that the linear unit cell parameters a, b and c change in a consistent manner with changing mechanical activation pressure, while the space-group symmetry D 2 h 16 –Pbnm is preserved. The sizes of the coherent scattering regions (D) decrease by more than 90% at the maximum mechanical activation pressure (1200 MPa). It was found that the mechanical activation pressures of YbFeO3 have a threshold value (800 MPa), above which the dislocation density decreases. According to the results of impedance spectroscopy, the nature of relaxation was found to be non-Debye and the activation energy increased from 0.649 eV for the starting sample to 1.395 eV for the sample mechanically activated sample at 1 GPa. The magnetization curves M(H) were described using the law of approach to magnetic saturation (LAS), and the critical crystallite size (Dcr) was determined to be 50 nm, at which the maximum Hc is observed. The behaviors of the spectroscopic splitting factor (g) and half-width (ΔH) of the electron paramagnetic resonance (EPR) spectrum are analogous to Hc and Mr, however, the maximum ΔH is observed in the range of 50–105 nm, and the g-factor reaches its maximum at particle sizes of 105 nm. [ABSTRACT FROM AUTHOR]