Structural, magnetic, dielectric and optical properties of the Eu2Bi2Fe4O12 bismuth-based low-temperature biferroic

Farfán, J. A. Cuervo; Vargas, Carlos Arturo Parra; Viana, D. S. F.; Milton, Flávio Paulo; Garcia, D.; Téllez, D.A. Landı́nez; Roa-Rojas, J.

doi:10.1007/s10854-018-0238-z

Cited by 5 publications

(8 citation statements)

References 29 publications

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“…The results of the total density of states for the two spin-up and spin-down polarizations under the distortional effect for R=Dy are presented in figure 6c. The most notable characteristics are the tendency of the material to adopt an insulating nature for the two spin orientations eliminating the semiconductor character and the permanence of the ferromagnetic behavior in accordance with the experimental results for R=Eu, Sm, and Dy, respectively (Cuervo-Farfán et al, 2018;Cuervo-Farfán et al, 2020;Nieto-Camacho et al, 2020). The average band gap calculated for the two spin orientations from the curves in figure 6c is 3.5 eV.…”

Section: Electronic Properties and Phase Transitionsupporting

confidence: 81%

“…Once the samples were obtained, we proceeded to the structural characterization by obtaining an X-ray diffraction pattern (XRD) at room temperature followed by a careful Rietveld analysis of the experimental data. The results of this analysis revealed that the most stable crystallization structure corresponded to the Pnma space group (number 62) characteristic of orthorhombic perovskite-type materials (Cuervo-Farfán et al, 2020;Cuervo-Farfán et al, 2018;Nieto-Camacho et al, 2020). For this crystalline system, an octahedral tilt of the type a + bb -, characterized by the existence of two rotation angles with similar magnitude values and opposite directions, is expected.…”

Section: Crystal Structurementioning

confidence: 88%

“…This material has a rhombohedral structure (space group R3c) at T=300 K (Xu et al, 2009) evidencing antiferromagnetism below the Néel temperature (T N ) of ≈640 K and ferroelectricity at temperatures below the Curie temperature (T C ) of ≈1100 K (Wu et al, 2010). When the bismuth ferrite BiFeO 3 binds to the rare-earth orthoferrite RFeO 3 described above, it allows the formation of a complex structure of the Bi 0.5 R 0.5 FeO 3 type (Cuervo-Farfán et al, 2018;Nieto-Camacho et al, 2020;Garrido et al, 2021).…”

Section: Perovskite-type Materialsmentioning

confidence: 99%

“…The complex impedance measurements as a function of temperature for the three materials of Bi 0.5 R 0.5 FeO 3 (R=Eu, Sm, and Dy) revealed the occurrence of a marked dispersion of the complex electric permittivity and evidenced Maxwell-Wagner-type relaxation processes that manifested in a substantial increase of the real part of the electrical permittivity (ε') with increasing temperature (Cuervo-Farfán et al, 2020;Cuervo-Farfán et al, 2018). These processes are considered electrically inhomogeneous due to incipient microscopic conduction mechanisms in the dielectric response (Lunkenheimer et al, 2002).…”

Section: Electric Responsementioning

confidence: 99%

“…DFT has proven to be a powerful tool in the prediction of various physical properties in perovskite-like materials (Alarcón-Suesca et al, 2019). To establish the magnetic and semiconducting character of the Bi 0.5 R 0.5 FeO 3 materials under analysis, we calculated the total density of states considering the structural group Pnma (number 62) for R=Eu (Cuervo-Farfán et al, 2018), R=Sm (Cuervo-Farfán et al, 2020, and R=Dy (Garrido et al, 2021). In all three cases, the total density of states exhibited the behavior exemplified in figure 6a for R=Dy considering the up and down spin orientations around the Fermi energy denoted as E F for E=0 eV.…”

Section: Electronic Properties and Phase Transitionmentioning

confidence: 99%

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Rare-earth ferrobismuthites: ferromagnetic ceramic semiconductors with applicability in spintronic devices

Roa-Rojas

Farfán

Toro

et al. 2022

Rev. Acad. Colomb. Cienc. Ex. Fis. Nat.

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We report here the synthesis process of the perovskite-like complex material Bi0.5R0.5FeO3 (R=Eu, Sm, Dy) using the ceramic method, as well as its structural, optical, magnetic, and electrical characterizations. Refined X-ray diffraction data revealed that this material crystallizes in an orthorhombic structure (space group Pnma number 62). The band gap value in the optical response shown in the diffuse reflectance spectroscopy curve was typical of semiconductor materials. The magnetization exhibited a very low coercive field hysteretic behavior, which is characteristic of weak ferromagnetism, for all temperatures examined below 300 K and the various magnetic fields applied. The real and complex electric permittivity curves showed the occurrence of dielectric relaxation processes at 113 K in agreement with reports of pyroelectric and thermo-stimulated currents as a function of temperature revealing the appearance of ferroelectric polarization below 113 K with possible magnetoelectric coupling. On the other hand, we made a theoretical study of the electronic structure with and without the inclusion of a Berry distortional phase and ab-initio calculations following the density functional theory formalism and the pseudopotential plane wave method. In this formalism, the exchange and correlation mechanisms are described by the generalized gradient approach (GGA + U) considering spin polarization. The Berry phase analysis suggested the occurrence of ferroelectricity at temperatures below 113 K consistent with the experimental analysis evidencing a biferroic behavior at low temperatures given that the distortional phase introduces hybridizations between the 3d-Fe and 2p-O states favoring the appearance of Dzyaloshinskii-Moriya interactions, which, in turn, facilitate the appearance of ferroelectricity coexisting with a weak ferromagnetism. The thermodynamic properties in the presence or absence of the Berry phase by means of the Debye quasiharmonic model revealed the appearance of a ferroelectric transition at 113 K, which corroborates their magnetoelectric nature at low temperatures. The ferromagnetic semiconducting character found at room temperature enhances this material for applications in spintronics technology.

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Section: Electronic Properties and Phase Transitionsupporting

confidence: 81%

Section: Crystal Structurementioning

confidence: 88%