Revealing polarons with high pressure on low electron-doped manganites

Pressure sensitivity (up to 1 GPa) of the electrical resistivity and of the ac susceptibility was measured for low electron-doping levels of Ca 1-xYxMnO3 (CYMO) and of Ca1-xSm xMnO3 (CSMO) ceramic samples (0.05≤x≤0.15). A very weak pressure dependence of the Curie temperature (Tc) was observed for b...

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Autores principales: Garbarino, G., Acha, C., Vega, D., Leyva, G., Polla, G., Martin, C., Maignan, A., Raveau, B.
Formato: JOUR
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_01631829_v70_n1_p014414_Garbarino
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Sumario:Pressure sensitivity (up to 1 GPa) of the electrical resistivity and of the ac susceptibility was measured for low electron-doping levels of Ca 1-xYxMnO3 (CYMO) and of Ca1-xSm xMnO3 (CSMO) ceramic samples (0.05≤x≤0.15). A very weak pressure dependence of the Curie temperature (Tc) was observed for both systems (∼6 K GPa-1), when compared to the hole-doped manganites of the same Tc (∼20 K GPa-1). Our results can be interpreted within a modified double exchange scenario, where pressure alters the reduction of the bandwidth produced by the electron-phonon interaction associated with small Fröhlich polarons in the weak to intermediate coupling regime.