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In response to the growing interest in materials exhibiting magneto-dielectric coupling across diverse application domains, we present a detailed study on the electrical behavior of Ba0.1Bi0.9(Ti0.9Zr0.1)0.1Fe0.9O3 (BBTZF) ceramic. This study includes a comprehensive analysis of temperature- and frequency-dependent dielectric behavior, along with ac impedance properties. The thermo-dielectric study in the temperature range of 300–650 K suggests the presence of an anomaly near the Neel temperature (TN = 603 K), supporting the strong magneto-dielectric coupling in BBTZF. The differential thermal study also revealed an anomaly around TN, characterized by an exothermic peak. Furthermore, the well-described experimental dielectric data as a function of frequency (100 Hz–1 MHz), by the Cole–Cole relaxation equation modified by introducing complex conductivity, demonstrated a remarkable change in the frequency of relaxation (fr) as a function of temperature in the vicinity of TN. This change is attributed to the coupling between magnetic and electric order parameters. Through the complex impedance analysis recorded at different temperatures, it was found that both the capacitance and resistance of the grain showed a change in behavior around TN, suggesting that the magneto-electric coupling is predominantly of intrinsic origin in our material. Furthermore, the intrinsic magneto-capacitance grain value is approximately − 0.36%, highlighting its potential for application in magnetoelectric devices. Finally, the ac conduction study has shown that magnetic ordering can influence the translational hopping of large polaron mechanisms. [ABSTRACT FROM AUTHOR]

Multiferroic ceramics Bi 1 - x Ba x Fe 0.5 - x Ti x Mn 0.5 O 3 with 0 ≤ x ≤ 0.2 has been prepared using solid-state method with sintering under N2 atmosphere. A detailed study on the interaction between the dielectric, magnetic, and transport properties in ceramic samples is referred. Rhombohedral phase was established for all the compositions. Dielectric properties have been improved by the reduction of dielectric loss (for x = 0.2, tan δ ⁓ 0.17). conduction mechanism have been deduced from the analysis of current density, no signature of Poole Frenkel (PF) has been designated, while the analyzed samples showed a predominance of the Ohmic conduction mechanism and the space charge-limited conduction (SCLC) mechanism. Moreover, ac conductivity study suggests a mechanism for small-polaron hopping at low temperatures, followed by the transfer of ionized oxygen vacancies at high temperatures. Besides, saturated hysteresis loops are observed in all BT concentrations. The highest saturation magnetization ( M S ≈ 0.107 emu / g ) was found for the composition x = 0.1. [ABSTRACT FROM AUTHOR]

The solid-state reaction technique was used to produce polycrystalline Bi1−xBaxFe1−x(Zn1/3Nb2/3)xO3 at different substitutions for x = 0, 0.025 and 0.05 (referred to as BFO, BBFZN25, and BBFZN50, respectively). Both x-ray diffraction and Raman spectroscopy revealed that the substitution did not affect the rhombohedral structure of BFO. However, the substitution did not prevent the formation of a second phase, which was identified as Bi25FeO39. The amount of this impurity phase was extracted through Rietveld refinement and was further corroborated by Mössbauer spectroscopy. Lattice parameters were found to be increased owing to substitution of larger ions on average. The substitution not only had an impact on average crystallite size, microstrain and dislocation density of BFO, but also had a significant effect on its dielectric properties. As a result, the dielectric permittivity was enhanced, with a notable reduction in dielectric loss. In particular, the magnitude of dielectric permittivity for the optimal composition BBFZN25 reached a value of 360 at room temperature (RT), which is much greater than that for pure BFO. This higher dielectric constant may be attributable to the larger average crystallite size. The reduction in dielectric loss, at RT, suggests an improvement in the electrical resistivity of BFO, caused by the reduction of the creation of oxygen vacancies and the generation of Fe2+. The non-formation of Fe2+ was verified through Mössbauer spectroscopy. The remarkable increase in the dielectric constant for BBFZN25 at higher temperatures (T > RT) is attributed to the interfacial polarization occurring at grain–grain boundary and internal barrier layers related to the Bi25FeO39 phase. [ABSTRACT FROM AUTHOR]