Interpretation of temperature-dependent resistivity of La0.7Ba0.3MnO3 manganites

Varshney, Dinesh; Shaikh, M. W.; Mansuri, Irfan

doi:10.1016/j.jallcom.2009.07.056

Cited by 27 publications

(18 citation statements)

References 41 publications

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“…Their model was found to fit very well the experimental data measured on polycrystalline samples [17,18,34,[39][40][41][42][43], while for epitaxial films, a good fit could be achieved only at low temperatures [35].…”

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confidence: 82%

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Polaron framework to account for transport properties in metallic epitaxial manganite films

et al. 2014

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We propose a model for the consistent interpretation of the transport behavior of manganese perovskites in both the metallic and insulating regimes. The concept of polarons as charge carriers in the metallic ferromagnetic phase of manganites also solves the conflict between transport models, which usually neglects polaron effects in the metallic phase, and, on the other hand, optical conductivity, angle-resolved spectroscopy, and neutron scattering measurements, which identify polarons in the metallic phase of manganites down to 6 K. Transport characterizations of epitaxial La 0.7 Sr 0.3 MnO 3 thin films in the thickness range of 5-40 nm and temperature interval of 25-410 K have been accurately collected. We show that taking into account polaron effects allows us to achieve an excellent fit of the transport curves in the whole temperature range. The current carriers density collapse picture accurately accounts for the properties variation across the metal-insulator transitions. The electron-phonon coupling parameter γ estimations are in a good agreement with theoretical predictions. The results promote a clear and straightforward quantitative description of the manganite films involved in charge transport device applications and promises to describe other oxide systems involving a metal-insulator transition. Ferromagnetic manganites are a prototypical example of the so-called half-metallic materials, i.e., materials with 100% spin polarization at 0 K. Although their possible application in commercial spintronics is prevented by a relatively low Curie temperature (T C 370 K), manganites represent an ideal laboratory tool to test spin transport in various materials and to search for pioneering device paradigms [1,2]. Thus, the use of manganites have significantly contributed to the field of organic spintronics, where almost half of the reported devices have La 0.7 Sr 0.3 MnO 3 (LSMO) as an injector [3]. In this context, revealing in a most exhaustive and comprehensive way, the transport properties of these materials looks both captivating and thought provoking.The transport properties of manganites are strongly linked to their ferromagnetism and are generally described in the framework of the so-called double-exchange mechanism: below T C the exchange interaction between Mn cations through oxygen anions favors ferromagnetism and electron delocalization along the Mn-O-Mn bonds, while above T C , thermal disorder disrupts this delocalization leading to a metal-insulator transition (MIT) [4]. Nevertheless, this basic picture appears to be conceptually insufficient to describe the physics of manganites, in general, and LSMO, in particular [5]: the strong role of polaron effects in manganites has been pointed out [6], and good experimental evidence has been provided by a variety of methods [6][7][8][9][10][11][12][13]. Moreover, manganites were proposed as an example of a polaron Fermi liquid [7].Although the presence of polarons in the metallic phase of LSMO (down to 6 K) has been demonstrated by optical * patrizio.gr...

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confidence: 82%

“…(iv) Finally, an accurate use of the Bloch-Grüneisen integral was attempted by Varshney et al [17,18,34,35,[39][40][41][42]. Their model was found to fit very well the experimental data measured on polycrystalline samples [17,18,34,[39][40][41][42][43], while for epitaxial films, a good fit could be achieved only at low temperatures [35].…”

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confidence: 99%

Polaron framework to account for transport properties in metallic epitaxial manganite films

et al. 2014

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“…(2) is due to the electron-phonon contribution which is explained by the Bloch-Gruneisen (BG) method to estimate the independent contributions of acoustic and optical phonons. The temperature dependent part of the resistivity, following the Debye model [32]:…”

Section: K Is Depicted Inmentioning

confidence: 99%

Structure and electrical resistivity of La1−xBaxMnO3 (0.25≤x≤0.35) perovskites

Mansuri

Varshney

2012

Journal of Alloys and Compounds

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“…The estimated electron parameters for La 0.7-Ca 0.25 K 0.05 MnO 3 (La 0.7 Ca 0.2 K 0.1 MnO 3 ) are the Fermi wave vector k F = 3.581 (4.586) 9 10 7 cm -1 , the Fermi velocity v F = 2.035 (2.105) 9 10 7 cms -1 and the plasma frequency x p = 1.406 (1.831) eV. We stress that the effects induced by electron correlations and mass renormalizations by electron-electron interactions are crucial in magnetic systems such as doped manganites [55][56][57][58][59][60][61][62][63][64][65].…”

Section: Discussion and Analysis Of Resultsmentioning

confidence: 87%

“…We notice that enhanced electron mass m * = 2.031 (2.514) m e in La 0.7 Ca 0.3-x K x MnO 3 leads to the reduced plasma frequency, and hence the reduced zero temperature elastic scattering rate in comparison to conventional metals. It is perhaps worth noticing that, in holedoped manganites, the scattering rate at low temperatures is of the order of 10 15 s -1 [55][56][57][58][59][60][61][62][63][64][65]. Furthermore, the MottIoffe-Regel criterion for metallic conductivity is valid, as the deduced mean free path is larger than the Mn-O bond length.…”

Section: Discussion and Analysis Of Resultsmentioning

confidence: 99%

Metallic and semi-conducting resistivity behaviour of La0.7Ca0.3−x K x MnO3 (x = 0.05, 0.1) manganites

Varshney

Dodiya

2014

J Theor Appl Phys

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The temperature dependence of electrical resistivity, q, of ceramic La 0.7 Ca 0.3-x K x MnO 3 (x = 0.05, 0.1) is investigated in metallic and semi-conducting phase. The metallic resistivity is attributed to be caused by electron-phonon, electron-electron and electron-magnon scattering. Substitutions affect average mass and ionic radii of A-site resulting in an increase in Debye temperature h D attributed to hardening of lattice with K doping. The optical phonon modes shift gradually to lower mode frequencies leading to phonon softening. Estimated resistivity compared with reported metallic resistivity, accordingly q diff. = [q exp. -{q 0 ? q e-ph (=q ac ? q op )}], infers electron-electron and electron-magnon dependence over most of the temperature range. Semi-conducting nature is discussed with variable range hopping and small polaron conduction model. The decrease in activation energies and increase in density of states at the Fermi level with enhanced Ca doping is consistently explained by cationic disorder and Mn valence.

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Interpretation of temperature-dependent resistivity of La0.7Ba0.3MnO3 manganites

Cited by 27 publications

References 41 publications

Polaron framework to account for transport properties in metallic epitaxial manganite films

Polaron framework to account for transport properties in metallic epitaxial manganite films

Structure and electrical resistivity of La1−xBaxMnO3 (0.25≤x≤0.35) perovskites

Metallic and semi-conducting resistivity behaviour of La0.7Ca0.3−x K x MnO3 (x = 0.05, 0.1) manganites

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