Colossal thermoelectric power in charge-ordered Li-doped La{sub 0.75}Li{sub 0.25}MnO{sub 3} manganite system
- Department of Physics, Kalyani Mahavidyalaya, Kalyani, Nadia, West Bengal-741235 (India)
- Department of Physics, Center for Nanoscience and Nanotechnology, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China)
- Applied Physics Department, Indian Institute of Technology (Banaras Hindu University), Varanasi-221 005 (India)
A detail study of transport and magnetic properties of La{sub 1-x}Li{sub x}MnO{sub 3+δ} (0.05 ≤ x ≤ 0.3) system synthesized by wet-chemical mixing route has been done. The room temperature x-ray powder diffraction (XRD) data show single phase behavior of all samples except x = 0.3. Rietveld refinement of XRD data shows structural transition from rhombohedral (R3-C) to orthorhombic (Pnma) symmetry occurs at the Li-doping level x > 0.2 with both the lattice parameter and unit-cell volume decrease with increase of ‘x’. All the samples show ferromagnetic (FM) behavior while metallic behavior are shown by the samples up to Li-concentration x = 0.2. With further Li doping i.e. for x = 0.25, the sample shows insulating behavior accompanied by charge-order transition around T ~ 225 K. Metallic part of the resistivity data of the samples is best fitted with an expression ρ(T) = ρ{sub 0} + ρ{sub 4.5}T{sup 4.5} + C/ sinh{sup 2}(hv{sub s}/2k{sub B}T) containing small-polaron contribution (last term). Most interesting finding in the present study is the observation of large anomalous decrease in thermoelectric power (S) below 100 K shown by the sample with x = 0.25. Probable mechanisms responsible for the observed colossal thermoelectric power have been discussed.
- OSTI ID:
- 22608779
- Journal Information:
- AIP Conference Proceedings, Vol. 1731, Issue 1; Conference: DAE solid state physics symposium 2015, Uttar Pradesh (India), 21-25 Dec 2015; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CONCENTRATION RATIO
CRYSTAL-PHASE TRANSFORMATIONS
DOPED MATERIALS
ELECTRICAL PROPERTIES
LANTHANUM COMPOUNDS
LATTICE PARAMETERS
LITHIUM ADDITIONS
LITHIUM COMPOUNDS
MAGNETIC PROPERTIES
MANGANATES
MIXING
ORTHORHOMBIC LATTICES
POLARONS
POWDERS
SYMMETRY
TEMPERATURE RANGE 0273-0400 K
TRIGONAL LATTICES
X-RAY DIFFRACTION