Magnetoelectric effect in multiferroic NdMn
                    <sub>2</sub>
                    O
                    <sub>5</sub>

Bukhari, Syed Hamad; Ahmad, Javed

doi:10.1088/1674-1056/26/1/018103

Cited by 12 publications

(3 citation statements)

References 31 publications

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“…Tesla, exactly in the ICM2/FE phase. Coinciding with the transition observed in the magnetization measurements in Fig 3(d), this variation could be related to a magnetic-fieldinduced transition CM+ICM2/FE → ICM2/FE [18,43] as a consequence of a renormalization of the KD g tensors. This renormalization increases with the level energy and could be helpful for the CF parameters modeling.…”

Section: Broadenings Of the Cf Excitations Are Similar To What We Hav...supporting

confidence: 63%

Probing the role of Nd3+ ions in the weak multiferroic character of NdMn2O5 by optical spectroscopies

et al. 2018

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Raman and infrared spectroscopies are used as local probes to study the dynamics of the Nd-O bonds in the weakly multiferroic NdMn2O5 system. The temperature dependence of selected Raman excitations reveals the splitting of the Nd-O bonds in NdMn2O5. The Nd 3+ ion crystal field (CF) excitations in NdMn2O5 single crystals are studied by infrared transmission as a function of temperature, in the 1800-8000 cm -1 range, and under an applied magnetic field up to 11 T. The frequencies of all 4 Ij crystal-field levels of Nd 3+ are determined. We find that the degeneracy of the ground-state Kramers doublet is lifted (∆0 ~7.5 cm -1 ) due to the Nd 3+ -Mn 3+ interaction in the ferroelectric phase, below TC ~ 28 K.The Nd 3+ magnetic moment mNd(T) and its contribution to the magnetic susceptibility and the specific heat are evaluated from ∆0(T) indicating that the Nd 3+ ions are involved in the magnetic and the ferroelectric ordering observed below ~ 28 K. The Zeeman splitting of the excited crystal field levels of the Nd 3+ ions at low temperature is also analyzed. dependent on the size of the rare-earth [2, 12-15]. The RMn2O5 compounds with large ionic radii (R= La and Pr) do not exhibit a detectable electric polarization and are considered as paraelectrics [14], while those with small ionic radii (R=Sm to Lu) display a finite electric polarization [13]. The intermediate size member of this family NdMn2O5 represents a particular case between the non-ferroelectric PrMn2O5 and the ferroelectric SmMn2O5. Recently, Chattopadhyay et al. [16-17] have revealed the weak ferroelectric character of this compound. The electric polarisation of NdMn2O5 (~2.4 μCm −2 ) is two orders of magnitude smaller than that of other multiferroic members of this series. Moreover, unlike the other multiferroic members of this family, its electrical polarization arises in an incommensurate magnetic state [13]. The RMn2O5 compounds crystallize in the orthorhombic structure [18-19] where edge-shared Mn 4+ O6 octahedra are connected along the c-axis and pairs of Mn 3+ O5 pyramids are linked to two Mn 4+ O6 chains. The rare earth ions are located in distorted RO8 polyhedra. However, there is no consensus on their space group symmetry. Indeed, a slight deviation from the Pbam space group has been recently observed in some compounds of this family [20]. The magnetic frustration of these systems is imposed by the geometric configuration. The loop of five adjacent Mn 3+ and Mn 4+ ions leads to a complex magnetic configuration in the RMn2O5 systems [1, 21-22]. The Mn 3+ and Mn 4+ moments are coupled antiferromagnetically by the exchange parameters J4 along the a-axis and J3 along the baxis [22]. The Mn 3+ moments, in two linked pyramids, couple antiferromagnetically via the exchange parameters J5. As a result of these numerous exchange parameters and the magnetic frustration, RMn2O5 multiferroics with small R ions show multiple phase transitions as a function of temperature. A magnetic transition to an antiferromagnetic order

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Section: Broadenings Of the Cf Excitations Are Similar To What We Hav...supporting

confidence: 63%

Probing the role of Nd3+ ions in the weak multiferroic character of NdMn2O5 by optical spectroscopies

et al. 2018

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“…These multiferroic compounds show variety of phase transitions in the low temperature range (2-45 K) along with strong magnetoelectric coupling. Previously, we have also investigated the low temperature phase transition in NdMn 2 O 5 , GdMn 2 O 5 , and DyMn 2 O 5 [8][9][10]. Remarkably, we have observed a new magnetic correlation in the dielectric response at slightly higher temperature above Néel temperature (T N ) [8,9].…”

Section: Introductionmentioning

confidence: 77%

Optical and dielectric spectroscopic analysis of SmMn₂O₅

Ahmad¹,

Bukhari²,

Khan³

et al. 2020

Phys. Scr.

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Polycrystalline SmMn2O5 has been synthesized by using sol-gel auto combustion tecnique. X-ray diffraction (XRD) pattern reflects the single phase formation of orthorhombic structure with Pbam space group. In the frequency range of (30–1000 cm−1) reflectivity spectrum reveals the 14 infrared active phonons out of 36, which are already pridicted theoretically. We have estimated the optical energy band gap (E g ) ≃ 1.5 eV from UV–visible absorption spectrum. Temperature dependent (293-533 K) DC electrical characterization up to 40 V suggests semiconducting nature of the material. The temperature dependent impedance spectroscopy within a broader frequency range of (20 Hz—3 GHz) shows decreasing behavior of dielectric constant and tangent loss while AC conductivity increasing with the rise in frequency and temperature suggest the strong frequency dispersion and relaxational behavior of the material. The activation energy calculation from AC conductivity is in good agreement with semiconducting material energy band gap.

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“…The similarity in magnetic structure of RMn 2 O 5 would imply the similarity of electric polarization in response to these magnetic ordering sequences in the low-T range. However, measured data from several systems [26][27][28][29] or even from the same system but different samples synthesized by different authors did show big scattering [18,[30][31][32] as shown in Fig. S1 of Supplementary Material.…”

Section: Introductionmentioning

confidence: 96%

Unusual tunability of multiferroicity in GdMn ₂ O ₅ by electric field poling far above multiferroic ordering point

Zheng

Tian

et al. 2019

Chinese Phys. B

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The multiferroicity in the RMn 2 O 5 family remains unclear, and less attention has been paid to its dependence on high-temperature (high-T ) polarized configuration. Moreover, no consensus on the high-T space group symmetry has been reached so far. In view of this consideration, one may argue that the multiferroicity of RMn 2 O 5 in the low-T range depends on the poling sequence starting far above the multiferroic ordering temperature. In this work, we investigate in detail the variation of magnetically induced electric polarization in GdMn 2 O 5 and its dependence on electric field poling routine in the high-T range. It is revealed that the multiferroicity does exhibit qualitatively different behaviors if the high-T poling routine changes, indicating the close correlation with the possible high-T polarized state. These emergent phenomena may be qualitatively explained by the co-existence of two low-T polarization components, a scenario that was proposed earlier.One is the component associated with the Mn 3+ -Mn 4+ -Mn 3+ exchange striction that seems to be tightly clamped by the high-T polarized state, and the other is the component associated with the Gd 3+ -Mn 4+ -Gd 3+ exchange striction that is free of the clamping. The present findings may offer a different scheme for the electric control of the multiferroicity in RMn 2 O 5 .

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Magnetoelectric effect in multiferroic NdMn ₂ O ₅

Cited by 12 publications

References 31 publications

Probing the role of Nd3+ ions in the weak multiferroic character of NdMn2O5 by optical spectroscopies

Probing the role of Nd3+ ions in the weak multiferroic character of NdMn2O5 by optical spectroscopies

Optical and dielectric spectroscopic analysis of SmMn₂O₅

Unusual tunability of multiferroicity in GdMn ₂ O ₅ by electric field poling far above multiferroic ordering point

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Magnetoelectric effect in multiferroic NdMn 2 O 5

Cited by 12 publications

References 31 publications

Probing the role of Nd3+ ions in the weak multiferroic character of NdMn2O5 by optical spectroscopies

Probing the role of Nd3+ ions in the weak multiferroic character of NdMn2O5 by optical spectroscopies

Optical and dielectric spectroscopic analysis of SmMn2O5

Unusual tunability of multiferroicity in GdMn 2 O 5 by electric field poling far above multiferroic ordering point

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Product

Resources

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Magnetoelectric effect in multiferroic NdMn ₂ O ₅

Optical and dielectric spectroscopic analysis of SmMn₂O₅

Unusual tunability of multiferroicity in GdMn ₂ O ₅ by electric field poling far above multiferroic ordering point