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

Abstract Influence of manganese substitution with 3 d -ions on the structure, defectiveness, microstructure as well as resistive, dielectric and magnetoresistive properties of single-phase nonstoichiometric La 0.6 Sr 0.15 Bi 0.15 Mn 1.1- x B x O 3- 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 Т ms 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 γ ph 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 γ ph takes the maximum value γ ph  ≈ 7.7.