Ac and dc magnetotransport properties of the phase-separated La(0.6)Y(0.1)Ca(0.3)MnO(3) manganite
Contribuinte(s) |
UNIVERSIDADE DE SÃO PAULO |
---|---|
Data(s) |
20/10/2012
20/10/2012
2008
|
Resumo |
The physical properties of the La(0.6)Y(0.1)Ca(0.3)MnO(3) compound have been investigated, focusing on the magnetoresistance phenomenon studied by both dc and ac electrical transport measurements. X-ray diffraction and scanning electron microscopy analysis of ceramic samples prepared by the sol-gel method revealed that specimens are single phase and have average grain size of similar to 0.5 mu m. Magnetization and 4-probe dc electrical resistivity rho(T,H) experiments showed that a ferromagnetic transition at T(C) similar to 170 K is closely related to a metal-insulator (MI) transition occurring at essentially the same temperature T(MI). The magnetoresistance effect was found to be more pronounced at low applied fields (H <= 2.5 T) and temperatures close to the MI transition. The ac electrical transport was investigated by impedance spectroscopy Z(f,T,H) under applied magnetic field H up to 1 T. The Z(f,T,H) data exhibited two well-defined relaxation processes that exhibit different behaviors depending on the temperature and applied magnetic field. Pronounced effects were observed close to T (C) and were associated with the coexistence of clusters with different electronic and magnetic properties. In addition, the appreciable decrease of the electrical permittivity epsilon`(T,H) is consistent with changes in the concentration of e(g) mobile holes, a feature much more pronounced close to T (C). |
Identificador |
JOURNAL OF MATERIALS SCIENCE, v.43, n.2, p.503-509, 2008 0022-2461 http://producao.usp.br/handle/BDPI/29331 10.1007/s10853-007-1822-4 |
Idioma(s) |
eng |
Publicador |
SPRINGER |
Relação |
Journal of Materials Science |
Direitos |
restrictedAccess Copyright SPRINGER |
Palavras-Chave | #COLOSSAL MAGNETORESISTANCE #TRANSPORT-PROPERTIES #SPECTROSCOPY #MN #CONDUCTIVITY #LA1-XCAXMNO3 #POLARIZATION #TEMPERATURE #RESISTIVITY #Materials Science, Multidisciplinary |
Tipo |
article proceedings paper publishedVersion |