High-temperature thermopower in La{sub {bold 2/3}}Ca{sub {bold 1/3}}MnO{sub {bold 3}} films: Evidence for polaronic transport
- Department of Physics, University of Illinois at Urbana-Champaign, 1110 W. Green Street, Urbana, Illinois 61801-3080 (United States)
- U.S. Naval Research Laboratory, Washington, D.C. 20375-5000 (United States)
Thermoelectric power, electrical resistivity, and magnetization experiments, performed in the paramagnetic phase of La{sub 2/3}Ca{sub 1/3}MnO{sub 3}, provide evidence for polaron-dominated conduction in colossal magnetoresistance materials. At high temperatures, a large, nearly-field-independent difference between the activation energies for resistivity {rho} and thermopower {ital S}, a characteristic of Holstein polarons, is observed, and ln{rho} ceases to scale with the magnetization. On approaching {ital T}{sub {ital c}}, both energies become field dependent, indicating that the polarons are magnetically polarized. Below {ital T}{sub {ital c}}, the thermopower follows a law {ital S}({ital H}){approximately}1/{rho}({ital H}) as in nonsaturated ferromagnetic metals. {copyright} {ital 1996 The American Physical Society.}
- Research Organization:
- University of Illinois
- DOE Contract Number:
- FG02-91ER45439
- OSTI ID:
- 388317
- Journal Information:
- Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 17 Vol. 54; ISSN 0163-1829; ISSN PRBMDO
- Country of Publication:
- United States
- Language:
- English
Similar Records
Transport-magnetism correlations in the ferromagnetic oxide La{sub 0.7}Ca{sub 0.3}MnO{sub 3}
Kinetic effects in manganites La{sub 1-x}Ag{sub y}MnO{sub 3} (y {<=} x)