Electronic transport by small polarons in La{sub 0.5}Sr{sub 0.5}MnO{sub 3}
Electrical conductivity measurements on La{sub 0.5}Sr{sub 0.5}MnO{sub 3} (LSM5) thin films as a function of temperature are presented. These are used to demonstrate that the electronic transport in LSM5 is well described by the Emin--Holstein adiabatic small polaron model. Measurements have also been performed on bulk samples. Even if the conductivity behaves somewhat differently in the latter case, the same polaronic model still applies. The polaron densities extracted from conductivity measurements are very similar, ranging from 7 to 8 x 10{sup 21}cm{sup -3} for thin films and are 9.1 x 10{sup 21}cm{sup -3} for bulk samples. These results agree quite well with the nominal polaron density for LSM5, 8.4 x 10{sup 21}cm{sup -3}. We have also derived important quantities for transport in LSM5. For thin films, we obtained hopping energies, W{sub H}, ranging between 73 and 99 meV and almost constant, at 34 meV, for bulk samples. By fitting conductivity measurements from 50 to 1123 K, we also find the zero point interaction constant, {gamma}{sub 0}, to be 0.35 in thin films. These conductivity results are compared with the literature. {copyright} 2001 American Institute of Physics.
- Sponsoring Organization:
- (US)
- OSTI ID:
- 40230553
- Journal Information:
- Journal of Applied Physics, Vol. 90, Issue 4; Other Information: DOI: 10.1063/1.1385356; Othernumber: JAPIAU000090000004001891000001; 040116JAP; PBD: 15 Aug 2001; ISSN 0021-8979
- Publisher:
- The American Physical Society
- Country of Publication:
- United States
- Language:
- English
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