(La0.4Ba0.4Ca0.2)(Mn0.4Ti0.6)O3: A new titano-manganate with a high dielectric constant and antiferromagnetic interactions

Jha, Pawan Kumar; Rai, Sarita; Ramanujachary, Kandalam V.; Lofland, S. E.; Ganguli, Ashok K.

doi:10.1016/j.jssc.2004.05.009

Cited by 19 publications

(26 citation statements)

References 27 publications

(40 reference statements)

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“…2͒ indicating that the powder was single phase as reported by Jha et al 4 A typical SEM micrograph of a LBCMT pellet sintered in air at 1150°C for 6 h is shown in Fig. 2͒ indicating that the powder was single phase as reported by Jha et al 4 A typical SEM micrograph of a LBCMT pellet sintered in air at 1150°C for 6 h is shown in Fig.…”

Section: Resultssupporting

confidence: 64%

“…6 Here we report an IS study of LBCMT ceramics prepared under the same preparative conditions as that reported by Jha et al 4 and reveal the origin of the high permittivity ͑Ͼ500͒ to be an "extrinsic" effect associated with a grainboundary response as opposed to being an intrinsic ͑bulk͒ effect. 1͑c͔͒.…”

Section: Introductionsupporting

confidence: 74%

“…In an attempt to miniaturize device size, much attention has been devoted to discover materials with high relative permittivity, low dielectric loss, and a low-temperature coefficient of the permittivity. 3 For example, Jha et al 4 recently reported a titano manganate perovskite, La 0.4 Ba 0.4 Ca 0.2 Mn 0.4 Ti 0.6 O 3 ͑LBCMT͒, that exhibits a high, frequency-dependent permittivity, ͑ eff ϳ 6980 and 590 at 1 and 100 kHz, respectively͒ at room temperature and antiferromagnetic interactions near 5 K. The compound has the ideal, cubic perovskite structure ͑space-group Pm3m, a ϳ 3.95 Å͒ and an average Mn oxidation state of +3.05. This approach has been very successful because such compounds are generally large band-gap insulators and, depending on the crystal symmetry, in particular, on the presence of octahedral tilting and/or cation displacement͑s͒, can contain up to three different polarization mechanisms ͑electronic, ionic, and dipolar͒ which can lead to high values of permittivity.…”

Section: Introductionmentioning

confidence: 99%

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Origin of the high permittivity in (La0.4Ba0.4Ca0.2)(Mn0.4Ti0.6)O3 ceramics

Feteira

Sinclair

2005

Journal of Applied Physics

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Articles you may be interested inEnhanced magnetoresistance induced by oxygen deficiency in La0.4Ca0.6MnO3-δ oxides Low temperature ac electrical study of Pr0.5−xLaxCa0.5MnO3 (x=0.0-0.4) ceramics by employing impedance spectroscopy Effect of electric field on magneto-transport properties in La2/3(Ca0.6Ba0.4)1/3MnO3/Pb(Zr0.52Ti0.48)O3 laminated composite Single-phase cubic ͑La 0.4 Ba 0.4 Ca 0.2 ͒͑Mn 0.4 Ti 0.6 ͒O 3 ͑LBCMT͒ was reported by Jha et al. ͓J. Solid State Chem. 177, 2881 ͑2004͔͒ to exhibit an extraordinarily high effective permittivity ͑ eff ϳ 6980 and 590 at 1 and 100 kHz, respectively͒ at room temperature. According to x-ray-diffraction analysis, the structure of this perovskite can be fully described on the centrosymmetric space-group Pm3m, which precludes the occurrence of ferroelectricity. In the present work, impedance spectroscopy has shown that LBCMT exhibits a bulk permittivity, r ϳ 40-45, in accordance with that expected for a cubic, centrosymmetric perovskite. LBCMT is a semiconductor with a bulk resistivity of ϳ3 k⍀ cm at 300 K and an activation energy for conduction of ϳ0.20 eV which is consistent with an electron hopping conduction mechanism. Finally, it is demonstrated that the high effective permittivity eff reported previously is not an intrinsic bulk effect arising from hopping conduction between Mn +3 and Mn +4 , but is ultimately associated with grain-boundary effects.

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Section: Resultssupporting

confidence: 64%

Section: Introductionsupporting

confidence: 74%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Origin of the high permittivity in (La0.4Ba0.4Ca0.2)(Mn0.4Ti0.6)O3 ceramics

Feteira

Sinclair

2005

Journal of Applied Physics

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“…The modified dielectric properties were used as capacitors, electronic memories, and optical filters. Materials exhibiting a giant dielectric constant were already reported elsewhere [25][26][27]. The high dielectric permittivity and the low loss factors over a wide frequency range are always of a great interest [28].…”

Section: Introductionmentioning

confidence: 91%

Mn3O4 Nanoparticles: Synthesis, Characterization, and Dielectric Properties

Dhaouadi¹,

Ghodbane²,

Hosni

et al. 2012

ISRN Spectroscopy

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Mn 3 O 4 nanoparticles were prepared by a simple chemical route using cetyltetramethylammonium bromide (CTAB) as a template agent. Mn 3 O 4 nanocrystals present an octahedral shape, and their crystallite size varies between 20 and 80 nm. They were characterized by XRD, SEM, DTA/TG, and IR spectroscopy. XRD studies confirm the presence of a highly crystalline Mn 3 O 4 phase. The Rietveld refinement of the X-ray diffraction data confirms that Mn 3 O 4 nanoparticles crystallize in the tetragonal system with space group I41/amd. DTA/TG and XRD measurements demonstrate the phase transition toward a spinel structure between 25 and 700 • C. The electrical conductivity increases between 80 and 300 • C, suggesting a semiconducting behaviour of Mn 3 O 4 . Both dielectric dispersion (ε ) and dielectric loss (ε ) were investigated from 80 and 300 • C in the frequency range of 10 Hz-13 MHz. The dielectric properties showed typical dielectric dispersion based on the Maxwell-Wagner model.

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“…[3][4][5] Despite the initial excitement concerning the discovery of possible "novel," intrinsic polarization mechanisms associated either with an unusual crystal structure or electronic charge ordering, it has been demonstrated in many cases that the giant r effect is often related to a well-known extrinsic Maxwell-Wagner-type polarization and is therefore not an intrinsic property associated with the material. [6][7][8] The formation of Schottky barriers 9,10 in electrically heterogeneous semiconductors is often the origin of an interfacial Maxwell-Wagner polarization mechanism and this leads to the observation of very high values of capacitance ͑ϳ0.1-10 nF cm −1 ͒, especially when measured at radio-frequencies ͑rfs͒.…”

Section: Introductionmentioning

confidence: 99%

Relaxor ferroelectric-like high effective permittivity in leaky dielectrics/oxide semiconductors induced by electrode effects: A case study of CuO ceramics

Feteira

Sinclair

2009

Journal of Applied Physics

117

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The electrical behavior of copper oxide ͑CuO͒ ceramics sintered at 920°C has been characterized by a combination of fixed, radio frequency ͑rf͒ capacitance measurements, and impedance spectroscopy ͑IS͒. Fixed rf capacitance measurements on ceramics with sputtered Au electrodes revealed a temperature-and frequency-dependent high effective permittivity of ϳ10 4 in the temperature range of 150-320 K. The response is similar to that observed for relaxor-ferroelectrics, however, the magnitude of the effect can be suppressed by thermal annealing of the ceramics with Au electrodes in air at 300°C or by changing the work function of the electrode material by using In-Ga as opposed to Au. IS data analysis revealed the ceramics to be electrically heterogeneous semiconductors with a room temperature dc resistivity Ͻ10 4 ⍀ cm, consisting of semiconducting grains with relative permittivity, r , Ͻ10 and slightly more resistive grain boundaries with "effective" permittivity, eff , of ϳ110. Samples with Au electrodes exhibited an additional low frequency response with eff ϳ 10 4 . dc bias experiments showed the capacitance behavior of this additional response to obey the Mott-Schottky law and thus confirm it to be a non-Ohmic electrode contact. We conclude, therefore, that an electrode rather than a grain boundary effect is the primary source for the high effective permittivity in CuO ceramics, although the latter is also present and does give additional effective permittivity. This work demonstrates how an extrinsic effect associated with non-Ohmic electrode contacts can; ͑i͒ dominate the rf capacitance spectra of leaky dielectrics/oxide semiconductors over a wide temperature and frequency range; and, ͑ii͒ manifest a dielectric response more typically associated with relaxor-ferroelectrics.

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(La0.4Ba0.4Ca0.2)(Mn0.4Ti0.6)O3: A new titano-manganate with a high dielectric constant and antiferromagnetic interactions

Cited by 19 publications

References 27 publications

Origin of the high permittivity in (La0.4Ba0.4Ca0.2)(Mn0.4Ti0.6)O3 ceramics

Origin of the high permittivity in (La0.4Ba0.4Ca0.2)(Mn0.4Ti0.6)O3 ceramics

Mn3O4 Nanoparticles: Synthesis, Characterization, and Dielectric Properties

Relaxor ferroelectric-like high effective permittivity in leaky dielectrics/oxide semiconductors induced by electrode effects: A case study of CuO ceramics

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