High-temperature colossal dielectric response in RFeO3 (R=La, Pr and Sm) ceramics

Huang, Shuai; Shi, Liang; Tian, Zhaoming; Yuan, Songliu; Wang, Liguang; Gong, Gaoshang; Yin, Chongyang; Zerihun, Gebru

doi:10.1016/j.ceramint.2014.08.124

Cited by 62 publications

(8 citation statements)

References 28 publications

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“…Meanwhile, both constants a and c decrease linearly with decrease in the R 3+ ionic radius, as indicated by the right-shifted peaks (112) and (200) in the samples from R = Ce to Sm. The monotonic decrease is related to the increased structural distortion in RFe 0.5 Cr 0.5 O 3 . , …”

Section: Results and Discussionmentioning

confidence: 97%

“…The monotonic decrease is related to the increased structural distortion in RFe 0.5 Cr 0.5 O 3 . 11, 32 The Raman spectra of the RFe 0.5 Cr 0.5 O 3 (R = Ce, Pr, Nd, Sm) ceramics were measured in the range of 50−900 cm −1 , as shown in Figure 1d, to reflect the structural distortion explicitly. It can be clearly seen that the vibration modes at 200−500 cm −1 shift to higher wavenumbers, indicating that the tilt angles of the Fe/CrO 6 octahedron increase with decrease in the R 3+ ionic radius, as observed in the parent RFeO 3 and RCrO 3 ceramics.…”

Section: Resultsmentioning

confidence: 99%

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Insight into the Magnetization Reversal and Exchange Bias in RFe_0.5Cr_0.5O₃ Ceramics

et al. 2021

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The R-dependent structural and magnetic properties of the disordered RFe 0.5 Cr 0.5 O 3 (R = Ce, Pr, Nd, Sm) ceramics are systemically investigated. Based on the model composed of the paramagnetic R sublattice and the canted antiferromagnetic Fe/Cr sublattice, by estimating the temperature-dependent magnetizations of the samples, it is found that the moments of polarized Pr 3+ and Nd 3+ are antiparallel to the moment of Fe 3+ /Cr 3+ in the compounds, which leads to the presence of magnetization reversal (MR) in NdFe 0.5 Cr 0.5 O 3 or suppressed MR in PrFe 0.5 Cr 0.5 O 3 due to the weak anisotropy, respectively. In addition, a giant positive (negative) exchange bias (EB) effect is observed distinctly in the R = Nd (Sm) compounds, which is attributed to the "pinning effect" of R on Fe/Cr spins due to the antiferromagnetic (ferromagnetic) coupling between the R and Fe/Cr sublattices. It is suggested that an intrinsic correlation exists between the MR and EB effects because of the magnetic interaction between the R and Fe/Cr sublattices. The sign of the EB field is determined by the competition between the Zeeman energy of the R 3+ spins and the coupling energy between Fe/Cr and R sublattices. These results contribute to the physical mechanism of the MR and EB effects, which are useful for the practical applications of RFe 0.5 Cr 0.5 O 3 ceramics.

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Section: Results and Discussionmentioning

confidence: 97%

Section: Resultsmentioning

confidence: 99%

Insight into the Magnetization Reversal and Exchange Bias in RFe_0.5Cr_0.5O₃ Ceramics

et al. 2021

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“…Among R FeO 3 compounds, lanthanum and samarium orthoferrites are two of the most studied materials because of combination of several intrigue properties [10–13]. At the ambient conditions, both LaFeO 3 and SmFeO 3 display the orthorhombic perovskite structure isotypic with GdFeO 3 [14, 15].…”

Section: Introductionmentioning

confidence: 99%

Structure Peculiarities of Micro- and Nanocrystalline Perovskite Ferrites La1−x Sm x FeO3

et al. 2017

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Micro- and nanocrystalline lanthanum-samarium ferrites La1−xSmxFeO3 with orthorhombic perovskite structure were obtained by using both solid state reactions (x = 0.2, 0.4, 0.6 and 0.8) and sol-gel synthesis (x = 0.5) techniques. Obtained structural parameters of both series of La1−xSmxFeO3 are in excellent agreement with the “pure” LaFeO3 and SmFeO3 compounds, thus proving formation of continuous solid solution in the LaFeO3–SmFeO3 system. Peculiarity of La1−xSmxFeO3 solid solution is divergence behaviour of unit cell dimensions with increasing x: systematic decrease of the a and c lattice parameters is accompanied with increasing b parameter. Such behaviour of the unit cell dimensions in La1−xSmxFeO3 series led to crossover of the a and c perovskite lattice parameters and formation of dimensionally tetragonal structure near x = 0.04. Linear decrease of the unit cell volume of La1−xSmxFeO3 with decreasing x according with the Vegard’s rule indicate absence of short-range ordering of R-cations in the LaFeO3–SmFeO3 system.

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“…23 Dielectric constant and dielectric loss have gradually decreased with rising frequency, such kind of nature has been explained by electrical polarization mechanisms. 24 In the lower frequency region dipoles have been displaced by an alternating electric field, it leads to higher value of dielectric constant; whereas at high frequency region, dipoles have displaced rapidly with changing field and is a significant reason for decreasing the dielectric constant.…”

Section: Resultsmentioning

confidence: 99%

Synthesis, Structural, Microscopic, and Electrical Properties Studies of Neodymium Chromite Perovskite Nanoparticles

Babu¹,

Ananthaiah²,

N³

et al. 2022

ECS J. Solid State Sci. Technol.

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NdCrO3 perovskite compound was synthesized via sol-gel auto-combustion process and the impedance spectroscopic data was studied in the wide frequency range (0.1Hz -10MHz), at various temperatures (RT-500°C). Structural analysis was done using Raman spectroscopy, which indicated single-phase orthorhombic structure. Energy dispersive X-ray diffraction and X-ray photoelectron spectroscopy showed Nd, Cr, O elements in the NdCrO3 compound, suggesting that the sample was pure. Scanning electron microscopy and transmission electron microscopy (TEM) analysis confirmed that the distribution of grains and particles was not uniform throughout the surface and material, respectively. TEM imaging indicated that the polycrystalline nature and particle size was on the order of 30-50 nm. This material showed the giant dielectric behavior (ε^'>〖10〗^4). Impedance studies of NdCrO3 perovskite exhibited a negative temperature coefficient of resistance type semiconductor behaviour. The dc conductivity and relaxation plots were followed by Arrhenius law. Frequency reliant ac conductivity plots followed Jonscher’s power law. These results suggest that NdCrO3 is suitable for giant capacitors applications.

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High-temperature colossal dielectric response in RFeO3 (R=La, Pr and Sm) ceramics

Cited by 62 publications

References 28 publications

Insight into the Magnetization Reversal and Exchange Bias in RFe_0.5Cr_0.5O₃ Ceramics

Insight into the Magnetization Reversal and Exchange Bias in RFe_0.5Cr_0.5O₃ Ceramics

Structure Peculiarities of Micro- and Nanocrystalline Perovskite Ferrites La1−x Sm x FeO3

Synthesis, Structural, Microscopic, and Electrical Properties Studies of Neodymium Chromite Perovskite Nanoparticles

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High-temperature colossal dielectric response in RFeO3 (R=La, Pr and Sm) ceramics

Cited by 62 publications

References 28 publications

Insight into the Magnetization Reversal and Exchange Bias in RFe0.5Cr0.5O3 Ceramics

Insight into the Magnetization Reversal and Exchange Bias in RFe0.5Cr0.5O3 Ceramics

Structure Peculiarities of Micro- and Nanocrystalline Perovskite Ferrites La1−x Sm x FeO3

Synthesis, Structural, Microscopic, and Electrical Properties Studies of Neodymium Chromite Perovskite Nanoparticles

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Insight into the Magnetization Reversal and Exchange Bias in RFe_0.5Cr_0.5O₃ Ceramics

Insight into the Magnetization Reversal and Exchange Bias in RFe_0.5Cr_0.5O₃ Ceramics