Electrical Resistivity Behavior and VRH Transport Mechanism in Semiconducting La0.6Sr0.4Mn1−2x Fe x Cr x O3 (0.10≤x≤0.25) Manganites

Sonia Ben Abdelkhalek (1) , Nabil Kallel (1) , Sami Kallel (1) , Thierry Guizouarn (2) , Octavio Peña (2) , Mohamed Oumezzine (1)

1 Laboratoire Physico-Chimie des Matériaux [Monastir]
2 ISCR - Institut des Sciences Chimiques de Rennes

The transport properties and conduction mechanism in La0.6Sr0.4Mn1−2x Fe x Cr x O3 (0≤x≤0.3) have been investigated. The undoped samples show metal-semiconductor transition with a peak of resistivity at a temperature T P , whereas for all doped compounds the semiconducting behavior persists in the whole temperature range. The insertion of Cr3+ and Fe3+ ions leads to the increase of resistivity because the simultaneous substitution of Fe3+ and Cr3+ for Mn3+ reduces the number of available hopping sites for the Mn e g↑ electron and suppresses the double-exchange mechanism. It was found that the transport mechanism for substituted samples is dominated by the variable range hopping of small polarons between localized states in a model where the various parameters estimated from Mott's relation obey the variable range hopping (VRH) mechanism.

Keywords: Manganites; Electrical properties; Conduction mechanism; VRH mechanism

Domains: Chemical Sciences; Material chemistry

Sonia Ben Abdelkhalek, Nabil Kallel, Sami Kallel, Thierry Guizouarn, Octavio Peña, et al.. Electrical Resistivity Behavior and VRH Transport Mechanism in Semiconducting La0.6Sr0.4Mn1−2x Fe x Cr x O3 (0.10≤x≤0.25) Manganites. Journal of Superconductivity and Novel Magnetism, 2013, pp.July 2013. ⟨10.1007/s10948-013-2291-4⟩. ⟨hal-00845670⟩