Processing and properties of pure antiferromagnetic h-YMnO3

Abstract

Yttrium manganite (YMnO 3) is widely investigated multiferroic material with potential use in many technological applications. In this paper, we report on the preparation and characterization of multiferroic hexagonal YMnO3 ceramics obtained by chemical synthesis route. Precursor powders were prepared by the polymerizable complex method from citrate precursors. After calcination at 900°C the powders contained mixture of Y-Mn-O phases which were further sintered at different temperatures. XRD analysis revealed that sintering at 1400°C resulted in the formation of pure hexagonal YMnO 3. Density of the obtained ceramics was 96 %TD. The ceramic samples proved to have multiferroic properties-they are antiferromagnetic below 42 K with linear dependence of magnetization as a function of applied magnetic field. The ferroelectric measurements performed at room temperature showed remanent polarization of 0.21 µC/cm 2 and the coercive field of 6.0 kV/cm for the YMnO 3 sample sintered at 1400°C. The magnetization curves measured at 2 and 5 K for the powder samples calcined at 900°C and ceramic samples sintered at 1300°C exhibited a hysteresis loop due to a small concentration of Mn 3 O 4 in the samples.

Grain-Size-Induced Collapse of Variable Range Hopping and Promotion of Ferromagnetism in Manganite La0.5Ca0.5MnO3

“…Sharp peak in the ZFC curve and a sudden jump in the FCC and FCW curves at T ≈ 40 K for S4000 share a striking resemblance with the behavior of magnetization in Mn 3 O 4 around its ferrimagnetic transition at T ≈ 43-48 K [67,68]. It is known that during the sample synthesis, small amounts of Mn 3 O 4 phase often appear within a manganite sample [69][70][71]. We therefore conclude that the behavior of magnetization for S4000 below ≈ 40 K is entirely extrinsic and related to small amounts of the Mn 3 O 4 phase rather than to an intrinsic re-entrant spin glass transition, commonly reported in the literature [64,[72][73][74].…”

Review on Resistive Switching Devices Based on Multiferroic BiFeO3

“…However, BFO has certain advantages over these materials, particularly in terms of its ferroelectric and magnetic properties, such as polarization, coercive field, remanent magnetization, and Curie temperature. For instance, BFO has a higher polarization and a lower coercive field than NZFO [3], and it has a higher Curie temperature and a lower remanent magnetization than YMO [8,9]. However, the RS mechanism responsible for the RS behavior in BFO memristive devices is still unclear, although several models have been proposed to understand the RS behavior, such as conductive filament [10], Schottky barrier [11], and ferroelectric tunneling [12].…”