Magnetic and impedance properties of magnetoelectric Co4Nb2O9

Yadav, Satish; Chandra, Mohit; Singh, Kiran

doi:10.1016/j.ceramint.2019.03.096

Cited by 4 publications

(6 citation statements)

References 29 publications

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“…This broad peak in tan(δ) lasts up to around 110 K. The temperature window of this relaxation behavior matches with the temperature range around which the deviation from Curie− Weiss law in magnetization is observed. 14,28 This indicates the presence of magnetic interactions much above the T N . The value of tan(δ) is also very small which supports the genuine dielectric relaxation.…”

Section: ■ Experimental Techniquesmentioning

confidence: 98%

“…Polycrystalline samples of CNO were prepared by a conventional solid-state reaction method as described previously. 28 The complex dielectric constant (ε*) is measured in parallelplate capacitor geometry. The flat surfaces of a well-sintered pellet of ∼8 mm diameter and ∼0.5 mm thickness are made as conducting plates by pasting silver paste on them.…”

Section: ■ Experimental Techniquesmentioning

confidence: 99%

“…This change matches with the dielectric relaxation regime. 28 The change in the lattice parameters at T N establishes the magnetoelastic coupling in CNO. Khanh et al also suggested that the MD effect in CNO is not originated from the conventional magnetostriction effect but from the spin-phonon coupling mediated by the magnetic ordering and lattice distortion.…”

Section: ■ Experimental Techniquesmentioning

confidence: 99%

“…That is why, relaxation in the dielectric behavior is observed. Furthermore, the Curie−Weiss fitting of the dc magnetization from high temperature does not follow the magnetization curve at temperature lower than 150 K. 16,28 In addition, heat capacity measurement by Papi et al 51 shows that the magnetic contribution in heat capacity persists until 100 K much higher than T N along with a peak around 27 K (T N ) and a cusp-like feature around 50 K. These observations support that the dielectric relaxation around 60 to 120 K is due to the lattice distortion mediated by spin-phonon coupling. Similar results were reported in geometrically frustrated spin chain system Ca 3 Co 2 O 6 because of the lattice distortion and presence of magnetic interactions well above the T N .…”

Section: ■ Experimental Techniquesmentioning

confidence: 99%

“…Polycrystalline samples of CNO were prepared by a conventional solid-state reaction method as described previously . The complex dielectric constant (ε*) is measured in parallel-plate capacitor geometry.…”

Section: Experimental Techniquesmentioning

confidence: 99%

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Temperature-Dependent Structural, Dielectric, and Raman Spectroscopy Studies on Magnetoelectric Co₄Nb₂O₉

et al. 2022

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Co 4 Nb 2 O 9 (CNO) is one of the interesting magnetoelectric materials. Here, we report comprehensive temperature-dependent structural, phonon, dielectric, and magnetic properties of CNO. In contrast to most of the earlier reports, a clear transition (upturn feature) is observed in temperature-dependent dielectric measurements at the antiferromagnetic ordering (T N ) ∼27.2 K, even in the absence of magnetic field. The upturn-like feature at T N (in zero magnetic field) becomes a sharp peak above the critical magnetic field. The isothermal magnetodielectric (MD) results infer magnetic field-induced transition below T N with nonlinear behavior. The maximum MD effect (∼4%) is observed at T N at 80 kOe. The terahertz measurements exhibit spin excitation mode below T N in the absence of magnetic field. The temperature-dependent synchrotron X-ray diffraction results demonstrate that the crystal structure of CNO remained P3̅ c1 down to 12 K; however, small distortion in the lattice is observed at T N . The temperature-dependent Raman measurements infer an unusual phonon shift and line width of optical phonons below T N . These results illustrate that CNO exhibits dielectric transition even in the absence of magnetic field and exhibit magnetoelastic coupling. The correlation in these order parameters is also discussed.

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Section: ■ Experimental Techniquesmentioning

confidence: 98%

Section: ■ Experimental Techniquesmentioning

confidence: 99%

Section: ■ Experimental Techniquesmentioning

confidence: 99%

Section: ■ Experimental Techniquesmentioning

confidence: 99%

Section: Experimental Techniquesmentioning

confidence: 99%

See 3 more Smart Citations