Modification of multifunctional properties of the magnetoresistive La0.6Sr0.15Bi0.15Mn1.1-xBxO3- ceramics when replacing manganese with 3d-ions of Cr, Fe, Co, Ni

Influence of manganese substitution with 3d-ions on the structure, defectiveness, microstructure as well as resistive, dielectric and magnetoresistive properties of single-phase nonstoichiometric La0.6Sr0.15Bi0.15Mn1.1-xBxO3-δ (B = Cr, Fe, Co, Ni) compositions have been studied. All compositions demonstrate slight lattice parameter change of rhombohedral R 3 ¯ c distorted perovskite structure. The molar formulas of a real perovskite structure have been determined. The real structure is defect and contains cation V(c) and anion V(a) vacancies. The resistivity ρ increases with increase of x for all compositions. There is no “metal-semiconductor” phase transition at temperature Тms for x ≥ 0.20. It has been shown that the composition with B = Cr has the highest relative permittivity at x = 0.3. For the first time, the electron-phonon interaction constant γph has been determined for all the compositions within the framework of small polaron hopping model and it has been found that the strongest change of functional properties is a characteristic of the compositions with B = Fe, for which γph takes the maximum value γph ≈ 7.7.