https://doi.org/10.1140/epjb/e2004-00251-5
Electrical resistivity in the ferromagnetic metallic state of La-Ca-MnO3: Role of electron-phonon interaction
School of Physics, Vigyan Bhawan, Devi Ahilya University, Khandwa Road
Campus, Indore 452017, India
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Received:
5
February
2004
Revised:
8
April
2004
Published online:
12
August
2004
Abstract
The temperature-dependent resistivity of the perovskite
manganites La
CaxMnO3, with x = 0.33, is theoretically
analysed within the framework of the classical electron-phonon model of
resistivity, i.e., the Bloch-Gruneisen model. Due to inherent acoustic
(low-frequency) phonons (
as well as high-frequency optical
phonons (
, the contributions to the resistivity have first
been estimated. The acoustic phonons of the oxygen-breathing mode yield a
relatively larger contribution to the resistivity compared to the
contribution of optical phonons. Furthermore, the nature of phonons changes
around T = 167 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.
and
,
when subtracted from thin film data, infers a power temperature dependence
over most of the temperature range. The quadratic temperature dependence of
is understood in terms of
electron-electron scattering. Moreover, in the higher temperature limit, the
difference can be varies linearly with T4.5 in accordance with the
electron-magnon scattering in the double exchange process. Within the
proposed scheme, the present numerical analysis of temperature dependent
resistivity shows similar results as those revealed by experiment.
PACS: 5.47.Gk – Colossal magnetoresistance / 72.15.-v – Electronic conduction in metals and alloys / 74.25.Kc – Phonons / 75.30.Ds – Spin waves
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2004

