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Magnetotransport, thermoelectric power, thermal conductivity and specific heat of Pr2/3Sr1/3MnO3 manganite.
- Source :
-
Journal of Applied Physics . Oct2008, Vol. 104 Issue 8, p083906. 6p. 1 Black and White Photograph, 1 Chart, 5 Graphs. - Publication Year :
- 2008
-
Abstract
- Magnetotransport and thermal studies of Pr2/3Sr1/3MnO3 polycrystalline sintered bulk sample are reported here. The resistivity ρ(T) and thermoelectric power S(T) data show an insulator to metal (I-M) phase transition at TP≈294 K and TS≈290 K, respectively. Magnetization measurement confirms that the sample undergoes a transition from paramagnetic to ferromagnetic phase at a defined Curie temperature TC=280 K. A substantial increase in magnetoresistance from 2.5% at 280 K to 5% at 77 K has been noticed in a low magnetic field 0.15 T. Small polaron hopping model is found to be operative above the transition temperature TP, whereas electron-electron and electron-magnon scattering processes govern the low temperature metallic behavior. A detailed analysis of thermoelectric power in the ferromagnetic regime suggests that the complicated temperature dependence of S may be understood on the basis of electron-magnon scattering. A transition from decreasing high temperature thermal conductivity (due to local anharmonic distortions associated with small polarons), to an increasing thermal conductivity (due to decreasing of phonon-phonon scattering) and thereafter a peak at ∼100 K (signifying a crossover from Umklapp to defect-limited scattering) have also been noticed. Specific heat measurements depict a pronounced anomaly near the TC, indicating the magnetic ordering and magnetic inhomogeneity in the sample. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00218979
- Volume :
- 104
- Issue :
- 8
- Database :
- Academic Search Index
- Journal :
- Journal of Applied Physics
- Publication Type :
- Academic Journal
- Accession number :
- 35041693
- Full Text :
- https://doi.org/10.1063/1.2992521