Magnetoresistance and magnetothermopower properties of Bi/Ca/Co/O and Bi(Pb)/Ca/Co/O misfit layer cobaltites
| Autor: | Antoine Maignan, Sylvie Hébert, Claude Michel, DI Khomskii, Denis Pelloquin, Maryvonne Hervieu |
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| Přispěvatelé: | Faculty of Science and Engineering |
| Rok vydání: | 2003 |
| Předmět: |
LARGE NEGATIVE MAGNETORESISTANCE
LA1-XSRXCOO3 Magnetoresistance Analytical chemistry TRIANGULAR LATTICE Mineralogy SUBSTITUTION Electronic structure Atmospheric temperature range Conductivity (BI PB)-SR-CO-O SYSTEM Condensed Matter Physics Magnetic susceptibility Cobaltite CO ELECTRONIC-STRUCTURE chemistry.chemical_compound chemistry Electrical resistivity and conductivity Seebeck coefficient SINGLE-CRYSTALS General Materials Science THERMOELECTRIC PROPERTIES CONDUCTIVITY |
| Zdroj: | Journal of Physics-Condensed Matter, 15(17):PII S0953-8984(03)55348-6, 2711-2723. IOP PUBLISHING LTD |
| ISSN: | 1361-648X 0953-8984 |
| DOI: | 10.1088/0953-8984/15/17/323 |
| Popis: | Two new compounds of the Bi/Ca/Co/O and Bi(Pb)/Ca/Co/O systems have been prepared. Their structure is built up from the intergrowth of four rock-salt-type layers and one [CoO2] hexagonal layer. Both cobaltites exhibit large thermopower values (S-300 K similar to 140 muV K-1), low resistivity values (rho(300) (K) 40-60 mOmega cm) and small thermal conductivities (kappa(300) (K) similar to I W K-1 m(-1)). Furthermore, these compounds exhibit a negative magnetoresistance, (MR = rho(H)-rho(H=0)/rho(H=0)), reaching, at 2.5 K, -85% in 7 T for the Bi/Ca/Co/O misfit cobaltite. A large negative magnetothermopower is also found for these cobaltites in the same temperature range. A qualitative explanation of the observed behaviour is proposed. |
| Databáze: | OpenAIRE |
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