Electronic transport in nanostructured thin films of perovskite manganite La0.67Ca0.33MnO3: role of grain boundaries

Paranjape, Mandar; Shankar, Karthik; Raychaudhuri, A. K.

doi:10.1088/0022-3727/38/19/016

Cited by 11 publications

(6 citation statements)

References 18 publications

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“…The sharp increase in magnetization can be related to ferromagnetic interactions that are probably due to intergrain domains, as they seem to appear at both low temperatures and magnetic fields, coinciding with the intergrain contribution to magnetization. The importance of the grain boundaries role has been also pointed up in relation to the electronic behaviour of similar perovskite systems [12]. The inset of Fig.…”

Section: Resultsmentioning

confidence: 82%

Oriented nanocrystals in SrLaMnTiO6 perovskite thin films grown by pulsed laser deposition

Álvarez-Serrano¹,

Larramendi²,

López³

et al. 2011

Journal of Alloys and Compounds

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Section: Resultsmentioning

confidence: 82%

Oriented nanocrystals in SrLaMnTiO6 perovskite thin films grown by pulsed laser deposition

Álvarez-Serrano¹,

Larramendi²,

López³

et al. 2011

Journal of Alloys and Compounds

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“…38 However, due to the presence of grain boundaries and structural/compositional inhomogeneities, there can be significant MR values at low temperatures. 39 MR values of À10% up to À20% around 5 K are indicative of the presence of the grain boundary effect (different chemical composition at the grain boundary than the bulk of the grain) in the 7501-and 8501Cannealed LSMO and LCMO films. Such behavior completely disappeared in the 9501C-annealed films, which can be explained due to grain growth.…”

Section: Resultsmentioning

confidence: 99%

“…Epitaxial half‐metallic manganite films also show maximum MR near the T c of the film 38 . However, due to the presence of grain boundaries and structural/compositional inhomogeneities, there can be significant MR values at low temperatures 39 . MR values of −10% up to −20% around 5 K are indicative of the presence of the grain boundary effect (different chemical composition at the grain boundary than the bulk of the grain) in the 750°‐ and 850°C‐annealed LSMO and LCMO films.…”

Section: Resultsmentioning

confidence: 99%

Mixed‐Valence Perovskite Thin Films by Polymer‐Assisted Deposition

Jain

Bauer

Ronning

et al. 2008

Journal of the American Ceramic Society

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In thin films of rare‐earth manganites, RE1−xMxMnO3 (RE=rare earth, M=Ca, Sr, Ba), with mixed‐valence perovskite structure, the transport properties highly depend on the deposition technique, processing conditions, and the substrate used. Chemical solution deposition techniques provide many advantages, such as low cost, easy setup, and coating of large areas. However, the crystalline quality, uniformity, and reproducibility of the film depend on the reactivity of the chemical used for solution preparation. In this paper, we report a novel process to grow rare‐earth manganite films using low‐cost polymer‐assisted deposition technique. In this process, polymer controls the viscosity and binds metal ions, resulting in a homogeneous distribution of metal precursors in the solution and a uniform film. These solutions were stable, and crack‐free films were obtained using these solutions. In this paper, thin films of La1−xSrxMnO3, La1−xCaxMnO3, and Pr0.5Ca0.5MnO3 were grown on (001) LaAlO3 substrates. The La1−xSrxMnO3 and La1−xCaxMnO3 films were highly c‐axis oriented and epitaxial, and showed high magnetoresistance near their Curie temperature. Charge ordering was observed in the Pr0.5Ca0.5MnO3 film at 220 K and high magnetoresistance of nearly −100% was obtained at low temperatures. The structural, transport, and magnetic properties of these films were similar to those obtained for films grown by physical vapor deposition.

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“…This investigation brought into picture the important estimate of the barrier to tunnelling occurring at the grain boundaries. The SPT in nanostructured films (grain sizes ∼ 30 nm) of LCMO and LSMO had been probed through investigations of I-V curves and magnetotransport in magnetic fields upto 6 T and down to 4 K 20,21 . The films showed prominent rise in resistivity below 40 K, although there was no clear signature of Coulomb charging.…”

Section: Introductionmentioning

confidence: 99%

Electrical transport properties of nanostructured ferromagnetic perovskite oxides La_0.67Ca_0.33MnO_3 and La_0.5Sr_0.5CoO_3 at low temperatures (5 K > T >0.3 K) and high magnetic field

Sarkar,

Kamalakar,

Raychaudhuri

2012

Preprint

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We report a comprehensive study of the electrical and magneto-transport properties of nanocrystals of La0.67Ca0.33MnO3 (LCMO) (with size down to 15 nm) and La0.5Sr0.5CoO3 (LSCO) (with size down to 35 nm) in the temperature range 0.3 K to 5 K and magnetic fields upto 14 T. The transport, magnetotransport and non-linear conduction (I-V curves) were analysed using the concept of Spin Polarized Tunnelling in the presence of Coulomb blockade. The activation energy of transport, ∆, was used to estimate the tunnelling distances and the inverse decay length of the tunnelling wave function (χ) and the height of the tunnelling barrier (ΦB). The magnetotransport data were used to find out the magnetic field dependences of these tunnelling parameters. The data taken over a large magnetic field range allowed us to separate out the MR contributions at low temperatures arising from tunnelling into two distinct contributions. In LCMO, at low magnetic field, the transport and the MR are dominated by the spin polarization, while at higher magnetic field the MR arises from the lowering of the tunnel barrier by the magnetic field leading to an MR that does not saturate even at 14 T. In contrast, in LSCO, which does not have substantial spin polarization, the first contribution at low field is absent, while the second contribution related to the barrier height persists. The idea of inter-grain tunnelling has been validated by direct measurements of the non-linear I-V data in this temperature range and the I-V data was found to be strongly dependent on magnetic field. We made the important observation that a gap like feature (with magnitude ∼ EC, the Coulomb charging energy) shows up in the conductance g(V) at low bias for the systems with smallest nanocrystal size at lowest temperatures (T ≤ 0.7 K). The gap closes as the magnetic field and the temperature are increased.

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Electronic transport in nanostructured thin films of perovskite manganite La_0.67Ca_0.33MnO₃: role of grain boundaries

Cited by 11 publications

References 18 publications

Oriented nanocrystals in SrLaMnTiO6 perovskite thin films grown by pulsed laser deposition

Oriented nanocrystals in SrLaMnTiO6 perovskite thin films grown by pulsed laser deposition

Mixed‐Valence Perovskite Thin Films by Polymer‐Assisted Deposition

Electrical transport properties of nanostructured ferromagnetic perovskite oxides La_0.67Ca_0.33MnO_3 and La_0.5Sr_0.5CoO_3 at low temperatures (5 K > T >0.3 K) and high magnetic field

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