Interpretation of Temperature-Dependent Resistivity of La–Pb–MnO3: Role of Electron–Phonon Interaction |
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Authors: | Dinesh Varshney N Kaurav |
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Affiliation: | (1) School of Physics, Vigyan Bhawan, Devi Ahilya University, Khandwa Road Campus, Indore, 452017, India |
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Abstract: | The present paper deals with the theoretical investigation of temperature-dependent resistivity of the perovskite manganites
La0.78Pb0.22MnO3-δ within the framework of the classical electron–phonon model of resistivity, i.e., the Bloch–Gruneisen model. Due to inherent
acoustic (low-frequency) phonons (ωac) as well as high-frequency optical phonons (ωop), the contributions to the electron–phonon resistivity have first been estimated. At low temperatures the acoustic phonons
of the oxygen-breathing mode yield a relatively larger contribution to the resistivity as compared to the contribution of
optical phonons. Furthermore, the nature of phonons changes around T = 215 K exhibiting a crossover from an acoustic to optical phonon regime with elevated temperature. The contribution to resistivity
estimated by considering both phonons, i.e., ωac and ωop, when subtracted from experimental data, infers a T4.5 temperature dependence over most of the temperature range. Deduced T4.5 temperature dependence of ρdiff = ρexp − {ρ0 + ρe-ph( = ρac + ρop)}] is justified in terms of electron–magnon scattering within the double exchange (DE) process. Within the proposed scheme,
the present numerical analysis of temperature dependent resistivity shows similar results as those revealed by experiments |
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Keywords: | CMR electron– phonon interaction spin wave excitations |
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