Small polaron migration associated multiple dielectric responses of multiferroic DyMnO3 polycrystal in low temperature region

Yang, Jianping; He, Juan; Zhu, Jianhui; Bai, Wei; Sun, Lin; Meng, Xin; Tang, Xiao; Duan, Chun‐Gang; Rémiens, Denis; Qiu, J.H.; Chu, Junhao

doi:10.1063/1.4768790

Cited by 29 publications

(21 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This means that the complex impedance contains only one constituent contribution at the atomic level, which can be considered as the source of the colossal dielectric permittivity, while it has nothing to do with any grain boundary effect. 25 The results are also in accordance with amorphous phase TiO 2 without apparent grain boundaries and long-range order as discussed earlier.…”

Section: Resultssupporting

confidence: 88%

A colossal dielectric constant of an amorphous TiO₂:(Nb, In) film with low loss fabrication at room temperature

et al. 2014

View full text Add to dashboard Cite

show abstract

Section: Resultssupporting

confidence: 88%

A colossal dielectric constant of an amorphous TiO₂:(Nb, In) film with low loss fabrication at room temperature

et al. 2014

View full text Add to dashboard Cite

show abstract

“…It is considered that the activation energy will be lower in the spin ordered state where electron hopping between ordered spins spend lower energy as compared to the hopping energy in the paramagnetic regime. [36,37] This is suggestive of a correlation between the magnetic and dielectric properties in YNMO.…”

Section: Dielectric and Impedance Measurementsmentioning

confidence: 76%

Ferromagnetism and the effect of free charge carriers on electric polarization in the double perovskiteY2NiMnO6

et al. 2015

View full text Add to dashboard Cite

The double perovskite Y 2 NiMnO 6 displays ferromagnetic transition at T c ≈ 81 K. The ferromagnetic order at low temperature is confirmed by the saturation value of magnetization (M s ) and also, validated by the refined ordered magnetic moment values extracted from neutron powder diffraction data at 10 K. This way, the dominant Mn 4+ and Ni 2+ cationic ordering is confirmed. The cation-ordered P 2 1 /n nuclear structure is revealed by neutron powder diffraction studies at 300 and 10 K. Analysis of frequency dependent dielectric constant and equivalent circuit analysis of impedance data takes into account the bulk contribution to total dielectric constant. This reveals an anomaly which coincides with the ferromagnetic transition temperature (T c ). Pyrocurrent measurements register a current flow with onset near T c and a peak at 57 K that shifts with temperature ramp rate. The extrinsic nature of the observed pyrocurrent is established by employing a special protocol measurement. It is realized that the origin is due to re-orientation of electric dipoles created by the free charge carriers and not by spontaneous electric polarization at variance with recently reported magnetism-driven ferroelectricity in this material. The double perovskite (DP) family of compounds with chemical formula R 2 M ′ M ′′ O 6 (R = rare earth, M ′ /M ′′ = transition metal) became an important research topic in the search for multifunctional materials by virtue of the wide variety of material properties shown by them, such as ferromagnetism, magnetocapacitance (MC), magnetoresistance (MR) and spin-phonon coupling.[1-4] Magnetic behavior of DPs is complex as a result of various exchange interactions between ions with different valencies (M ′3+ , M ′4+ , M ′′3+ , M ′′2+ , etc.) mediated through the intervening oxygen. These valencies are stabilized in DPs due to the presence of "antisite" disorder where M ′ and M ′′ cations interchange their respective crystallographic positions.[5] The ground state magnetic properties of double perovskites are determined by the degree of cationic ordering of the transition metal ions, M ′ and M ′′ . In ordered DPs i.e., where the M ′ and M ′′ ions are ordered crystallographically, M ′4+ and M ′′2+ layers alternate periodically.[5] Ordered R 2 NiMnO 6 DPs are ferromagnetic (FM) due to the Mn 4+ -O-Ni 2+ superexchange interaction conforming to Goodenough-Kanamori rules.[6] The inevitable presence of "antisite" disorder can introduce additional antiferromagnetic (AFM) interactions across the exchange pathways such as Mn 4+ -O-Mn 4+ and Ni 2+ -O-Ni 2+ .[7]A recent excitement in the field of DPs has risen from the prospect of realizing multiferroics.According to density functional theory calculations, R 2 NiMnO 6 series of compounds with small rare earth ions are predicted to be multiferroic from the nature of E * -type (↑↑↓↓ ) magnetic ordering which breaks the inversion symmetry and generates spontaneous electric polarization. [8] More recently, experimental evidences for multiferroicity have been reported...

show abstract

“…where N(E F ) is the density of localized states at the Fermi level, and ξ is the decay length of the localized wavefunction. This approach has been used in the interpretation of conductivity data of several oxides [37][38][39], including DyMnO 3 [22]. The temperature dependence of the dc conductivity of both samples, obtained by equation ( 1), was analysed with equations ( 3) and (4).…”

Section: Resultsmentioning

confidence: 99%

“…Concerning microstructural and dielectric inhomogeneity, the dielectric response of polycrystalline ceramics is a rather more challenging open issue. Although there are few dielectric investigations of TbMnO 3 [21], DyMnO 3 [22], and DyMn 1−x Fe x O 3 [23] polycrystals, with the exception of the recent work by Yang et al [22], the reported dielectric data were mainly concentrated in the fairly high temperature range above 100 K. Considering the rich physical phenomena at low temperatures, extending dielectric studies to lower temperatures is of fundamental interest. Systematic investigations could help elucidate the correlations between dielectric properties, electrical transport and magnetic ordering, and provide new insights into the nature of magnetoelectric and magnetocapacitive effects in rare-earth manganites.…”

Section: Introductionmentioning

confidence: 99%

Charge carriers and small-polaron migration as the origin of intrinsic dielectric anomalies in multiferroic TbMnO₃polycrystals

Silveira

Dias

Cótica

et al. 2013

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

Temperature-dependent and frequency-dependent dielectric investigations have been performed in TbMnO3 polycrystals sintered in either oxidative or reductive atmospheres. The results revealed the occurrence of two dielectric anomalies above 100 K, which are caused by the thermal activation of charge carriers and their motion in grain cores and grain boundaries. The temperature dependence of the bulk dc conductivity was also analysed and indicates that charge carriers move between inequivalent sites according to a variable-range-hopping mechanism. Also, a strong correlation between dielectric properties and crystalline structure was observed. Furthermore, a low-temperature dielectric relaxation, commonly reported in rare-earth manganite crystals, was observed in both samples. This relaxation follows the empirical Cole-Cole model and was attributed to small-polaron tunnelling. Polaron motion was observed to be affected by the magnetic transitions, structural properties and intrinsic anisotropies in TbMnO3. It is also worth mentioning that the dielectric anomaly due to motion of charge carriers in grain boundaries is the only one of extrinsic origin, while the anomalies related to carrier motion in grain cores and small-polaron tunnelling are intrinsic to TbMnO3.

show abstract

Small polaron migration associated multiple dielectric responses of multiferroic DyMnO3 polycrystal in low temperature region

Cited by 29 publications

References 41 publications

A colossal dielectric constant of an amorphous TiO₂:(Nb, In) film with low loss fabrication at room temperature

A colossal dielectric constant of an amorphous TiO₂:(Nb, In) film with low loss fabrication at room temperature

Ferromagnetism and the effect of free charge carriers on electric polarization in the double perovskiteY2NiMnO6

Charge carriers and small-polaron migration as the origin of intrinsic dielectric anomalies in multiferroic TbMnO₃polycrystals

Contact Info

Product

Resources

About

Small polaron migration associated multiple dielectric responses of multiferroic DyMnO3 polycrystal in low temperature region

Cited by 29 publications

References 41 publications

A colossal dielectric constant of an amorphous TiO2:(Nb, In) film with low loss fabrication at room temperature

A colossal dielectric constant of an amorphous TiO2:(Nb, In) film with low loss fabrication at room temperature

Ferromagnetism and the effect of free charge carriers on electric polarization in the double perovskiteY2NiMnO6

Charge carriers and small-polaron migration as the origin of intrinsic dielectric anomalies in multiferroic TbMnO3polycrystals

Contact Info

Product

Resources

About

A colossal dielectric constant of an amorphous TiO₂:(Nb, In) film with low loss fabrication at room temperature

A colossal dielectric constant of an amorphous TiO₂:(Nb, In) film with low loss fabrication at room temperature

Charge carriers and small-polaron migration as the origin of intrinsic dielectric anomalies in multiferroic TbMnO₃polycrystals