Thermoelectric power of Na-doped La0.7Ca0.3-yNayMnO3 both in the presence and the absence of magnetic field

S Bhattacharya, A Banerjee, S Pal, RK Mukherjee, BK Chaudhuri

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Abstract

Magnetic-field (B=0–1.5 T) dependent thermoelectric power (TEP) of the Na-doped La0.7Ca0.3−yNayMnO3 (0.0⩽y⩽0.3) system has been studied in the temperature range 80–300 K. X-ray diffraction studies indicate a rhombohedrally distorted perovskite structure of the samples. The observed sharp peak in the resistivity (ρ) versus temperature (T) curve falls and shifts to higher temperature with increasing Na concentration (y). In the low-temperature ferromagnetic (FM) regime, thermopower (Seebeck coefficient, S) obeys the expression S=S0+S1.5T1.5+S4T4 over the entire range of y. Electron-magnon scattering is found to dominate the low-temperature resistivity and TEP data. High-temperature TEP data can be well fitted with Mott’s small polaron hopping model. The activation energy (ES) and polaron hopping energy (WH) decrease with increasing Na content. Both ES and WH decrease while polaron radius (rp) increase with the application of a magnetic field. Field-dependent TEP data also indicate the suppression of spin fluctuations in the presence of a magnetic field. In the low-temperature FM region, both magnon drag and phonon drag effects coexist.
Original languageEnglish
Article number356
JournalJournal of Applied Physics
Volume93
Issue number1
DOIs
Publication statusPublished - 2003
MoE publication typeA1 Journal article-refereed

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drag
magnetic fields
electrical resistivity
Seebeck effect
electron scattering
retarding
activation energy
radii
temperature
shift
curves
diffraction
x rays
energy

Cite this

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title = "Thermoelectric power of Na-doped La0.7Ca0.3-yNayMnO3 both in the presence and the absence of magnetic field",
abstract = "Magnetic-field (B=0–1.5 T) dependent thermoelectric power (TEP) of the Na-doped La0.7Ca0.3−yNayMnO3 (0.0⩽y⩽0.3) system has been studied in the temperature range 80–300 K. X-ray diffraction studies indicate a rhombohedrally distorted perovskite structure of the samples. The observed sharp peak in the resistivity (ρ) versus temperature (T) curve falls and shifts to higher temperature with increasing Na concentration (y). In the low-temperature ferromagnetic (FM) regime, thermopower (Seebeck coefficient, S) obeys the expression S=S0+S1.5T1.5+S4T4 over the entire range of y. Electron-magnon scattering is found to dominate the low-temperature resistivity and TEP data. High-temperature TEP data can be well fitted with Mott’s small polaron hopping model. The activation energy (ES) and polaron hopping energy (WH) decrease with increasing Na content. Both ES and WH decrease while polaron radius (rp) increase with the application of a magnetic field. Field-dependent TEP data also indicate the suppression of spin fluctuations in the presence of a magnetic field. In the low-temperature FM region, both magnon drag and phonon drag effects coexist.",
author = "S Bhattacharya and A Banerjee and S Pal and RK Mukherjee and BK Chaudhuri",
year = "2003",
doi = "10.1063/1.1527220",
language = "English",
volume = "93",
journal = "Journal of Applied Physics",
issn = "0021-8979",
publisher = "American Institute of Physics AIP",
number = "1",

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Thermoelectric power of Na-doped La0.7Ca0.3-yNayMnO3 both in the presence and the absence of magnetic field. / Bhattacharya, S; Banerjee, A; Pal, S; Mukherjee, RK; Chaudhuri, BK.

In: Journal of Applied Physics, Vol. 93, No. 1, 356, 2003.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Thermoelectric power of Na-doped La0.7Ca0.3-yNayMnO3 both in the presence and the absence of magnetic field

AU - Bhattacharya, S

AU - Banerjee, A

AU - Pal, S

AU - Mukherjee, RK

AU - Chaudhuri, BK

PY - 2003

Y1 - 2003

N2 - Magnetic-field (B=0–1.5 T) dependent thermoelectric power (TEP) of the Na-doped La0.7Ca0.3−yNayMnO3 (0.0⩽y⩽0.3) system has been studied in the temperature range 80–300 K. X-ray diffraction studies indicate a rhombohedrally distorted perovskite structure of the samples. The observed sharp peak in the resistivity (ρ) versus temperature (T) curve falls and shifts to higher temperature with increasing Na concentration (y). In the low-temperature ferromagnetic (FM) regime, thermopower (Seebeck coefficient, S) obeys the expression S=S0+S1.5T1.5+S4T4 over the entire range of y. Electron-magnon scattering is found to dominate the low-temperature resistivity and TEP data. High-temperature TEP data can be well fitted with Mott’s small polaron hopping model. The activation energy (ES) and polaron hopping energy (WH) decrease with increasing Na content. Both ES and WH decrease while polaron radius (rp) increase with the application of a magnetic field. Field-dependent TEP data also indicate the suppression of spin fluctuations in the presence of a magnetic field. In the low-temperature FM region, both magnon drag and phonon drag effects coexist.

AB - Magnetic-field (B=0–1.5 T) dependent thermoelectric power (TEP) of the Na-doped La0.7Ca0.3−yNayMnO3 (0.0⩽y⩽0.3) system has been studied in the temperature range 80–300 K. X-ray diffraction studies indicate a rhombohedrally distorted perovskite structure of the samples. The observed sharp peak in the resistivity (ρ) versus temperature (T) curve falls and shifts to higher temperature with increasing Na concentration (y). In the low-temperature ferromagnetic (FM) regime, thermopower (Seebeck coefficient, S) obeys the expression S=S0+S1.5T1.5+S4T4 over the entire range of y. Electron-magnon scattering is found to dominate the low-temperature resistivity and TEP data. High-temperature TEP data can be well fitted with Mott’s small polaron hopping model. The activation energy (ES) and polaron hopping energy (WH) decrease with increasing Na content. Both ES and WH decrease while polaron radius (rp) increase with the application of a magnetic field. Field-dependent TEP data also indicate the suppression of spin fluctuations in the presence of a magnetic field. In the low-temperature FM region, both magnon drag and phonon drag effects coexist.

U2 - 10.1063/1.1527220

DO - 10.1063/1.1527220

M3 - Article

VL - 93

JO - Journal of Applied Physics

JF - Journal of Applied Physics

SN - 0021-8979

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M1 - 356

ER -