Percolation Model of the Temperature Dependence of Resistivity in Pr(0.67)A(0.33)MnO(3) (A = Ba or Sr) Manganites

S. Hcini , S. Khadhraoui , S. Zemni (1) , A. Triki , H. Rahmouni , M Boudard (2) , M. Oumezzine (1, 3)

1 SIMaP - Science et Ingénierie des Matériaux et Procédés
2 LMGP - Laboratoire des matériaux et du génie physique
3 Unité GEOGLOB

The analyses of resistivity experimental results of Pr0.67Ba0.33MnO3 (PBMO) and Pr0.67Sr0.33MnO3 (PSMO) manganites are presented. The electrical resistivity curves are fitted with the phenomenological percolation model, which is based on the phase segregation of ferromagnetic-metallic (FMM) clusters and paramagnetic-insulating (PMI) regions. The estimated results are in good agreement with experimental data. We found that the transition to the metallic state occurs if the volume fraction of the ferromagnetic phase reaches a percolation threshold, suggesting that the percolation of ferromagnetic (FM) domains is responsible for the observed metal-insulator (M-I) transition. According to the percolation model, we found that the energy gap of the quasi-particles in the phase separated FM and PM states is significantly smaller for PBMO than that for PSMO confirming that PSMO is more conductive than PBMO. We also found that the volume fraction of the ferromagnetic phase has the same physical meaning as the reduced magnetization.

Domaines: Matériaux

S. Hcini, S. Khadhraoui, S. Zemni, A. Triki, H. Rahmouni, et al.. Percolation Model of the Temperature Dependence of Resistivity in Pr(0.67)A(0.33)MnO(3) (A = Ba or Sr) Manganites. Journal of Superconductivity and Novel Magnetism, 2013, 26 (6), pp.2181-2185. ⟨10.1007/s10948-012-1812-x⟩. ⟨hal-01067629⟩