Enhanced magnetic and dielectric properties of Ti‐doped YFeO₃ ceramics

Abstract

Polycrystalline YFeO3 (YFO) and YFe1−(4/3)xTixO3(YFTO) ceramics were prepared using the powder synthesized from the sol‐gel route. X‐ray diffraction analyses of the polycrystalline ceramics revealed the crystallization of the phase in orthorhombic crystal structure associated with the space group Pnma. The magnetization versus magnetic field hysteresis loops were obtained at room temperature for YFO and YFTO ceramics. The magnetic property changes from weak ferromagnetic in YFO to ferromagnetic in YFTO ceramics. The dielectric constant recorded at room temperature for YFTO ceramics was six times higher than that of YFO, whereas the dielectric loss gets reduced to 0.06 from 0.3 for YFO at 1 kHz. Impedance spectroscopy study carried out on YFO and YFTO ceramics confirmed the existence of non‐Debye‐type relaxation. Observed single semicircle in Z′ vs −Z′′ plot established the incidence of intrinsic (bulk) effect and ruled out any grain boundary or electrode effects. The mechanism for the dielectric relaxation and electrical conduction process observed in YFO and YFTO ceramics was discussed by invoking electric modulus formalisms. Activation energy obtained by ac conductivity study suggested that the conduction process in YFO was linked up with the existence of the polaron and oxygen vacancies, whereas only oxygen vacancies contribute to the conduction process in YFTO ceramics.

The role of the interface on magnetic properties for YFeO3@Al2O3 core–shell structure

“…However, the YFeO 3 ceramic compound has shown to behave as soft and hard magnet depending on crystal size and morphology. Recently, S. Madolapa et al and others [12,13,19] found very similar M(H) profile hysteresis curves to that reported in this work assuming a large magnetic anisotropy as a consequence of crystal size. Recently, V. I. Povkov et al [20] found a strong dependence of the M-H curves with the crystal morphology.…”

Enhanced Multiferroic Properties of YFeO3 by Doping with Bi3+

“…As can be observed, the bismuth concentration directly correlated to changes in the relaxation process in all samples. It has been demonstrated that doping produces the appearance of new dielectric relaxation that can be associated at oxygen vacancies [11,17]. Liberated electrons from oxygen vacancies can be taken by Fe 3+ ions and change their oxidation state to Fe 2+ ions [42].…”

“…The centrosymmetric nature of this material is responsible for ferroelectric and weak ferromagnetic behaviors at room temperature. It presents a magnetic transition at the Neel temperature of ~640 K [11,12]. Magnetic ordering is related to three types of magnetic interactions in atoms bonds: Y-Y, Y-Fe and Fe-Fe where Fe-O-Fe super-exchange interaction is the main source of the weak ferromagnetic behavior as well as the canting of magnetic moments of Fe 3+ due to the Dzyaloshinskii-Moriya (DM) interaction [10,13].…”

“…Further, the results showed the important role of oxygen vacancies toward the dielectric relaxation process [3,17]. Madolappa et al [11] reported an increased coercive field of YFeO 3 related with the use of Ti 4+ as a doping ion. They demonstrated that the dielectric relaxation process corresponded to the non-Debye type.…”

Structural, ferroelectric, and optical properties of Bi3+ doped YFeO3: A first‐principles study

“…[ 5 ] Many works are focused on the effects of the magnetic properties of YFeO 3 upon doping of the A (Y 3+ ) or B (Fe 3+ ) sites with different ions (Ca, Gd, Er, Mn, Ti, Bi). [ 2,6–10 ] However, there are hardly any reports on their ferroelectric properties. From a theoretical point of view, Zhang et al [ 11 ] studied the effect of Y (6.25%) substitution on the structural and electronic properties of BiFeO 3 using density functional theory calculations.…”