Magnetotransport and dielectric properties of Bi-containing La0.6Sr0.15Bi0.15Mn1.1-xBxO3-δ rare-earth manganites with B = Cr, Fe, Co, Ni

摘要

The effect of the replacement of manganese by Spions of transition metals on the structural, microstructural, dielectric, and magnetotransport properties of nonstoichiometric La_0.6Sr_0.15Bi_0.15Mn_1.1-xB_xO_3-δ compositions with B = Cr, Fe, Co and Ni (0 ≤ χ ≤ 0.3) was investigated. It is shown that in all compositions a weak change for the lattice parameter of the rhombohedral perovskite structure is observed. It is established that the real structure is defective and contains cationic V(c) and anionic V(a) vacancies. With increasing χ, an increase in the resistivity and the absence of a metal-semiconductor phase transition for χ > 0.20 are observed. The electron-phonon interaction constant /ph was determined. The most significant change in the structural and functional properties was observed for the compositions with B = Fe, for which constant γ_ph ≈ 7.7 achieves a maximum value. At χ = 0.05, an increase in magnetoresistance effect of the tunnel type is observed.