Revealing polarons with high pressure on low electron-doped manganites

Abstract

Pressure sensitivity (up to 1 GPa) of the electrical resistivity and of the ac susceptibility was measured for low electron doping levels of Ca${}_{1-x}$Y${}_x$MnO${}_3$ (CYMO) and of Ca${}_{1-x}$Sm${}_x$MnO${}_3$ (CSMO) ceramic samples (0.05 $\le$ x $\le$ 0.15). A very weak pressure dependence of the Curie temperature (T${}_c$) was observed for both systems ($\sim$ 6 K GPa${}^{-1}$), when compared to the hole-doped manganites of the same T${}_c$ ($\sim$ 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.

arXiv comment6 Revtex pages, 5 EPS figures included, submitted to Phys. Rev. B. Contact author: C. Acha (e-mail address: [email protected])

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Cited by in corpus (3)

• Polaron Transport in the Paramagnetic Phase of Electron-Doped Manganites
• A phenomenological model for the pressure sensitivity of the Curie temperature in hole-doped manganites
• Electrical transport properties of manganite powders under pressure