Crystal structure, magnetic and electrical properties and thermal expansion of ferrites of the system Sr1–xSmxFe12–xZnxO19 ( x= 0–0.5)

Abstract

High-coercivity ferrite samples Sr1–xSmxFe12–xZnxO19 (x = 0–0.5) with magnetoplumbite structure were prepared from oxides Fe2O3, Sm2O3, ZnO and carbonate SrCO3by solid-state ceramic method, the dependence of the unit cell parameters aand con the value of x was determined. It was determined that samples of Sr1–xSmxFe12–xZnxO19were single-phased up to x= 0.2, and also contained ?-Fe2O3for x ?0.3 phase, quantity of which gradually increased with increasing xup to 0.5, and small quantities of phases ZnFe2O4and SmFeO3were present in the samples with x= 0.4 and 0.5. The magnetic, electrical properties and thermal expansion of these ferrite samples were studied, the values of specific saturation magnetization (?s ) were determined by magnetic hysteresis loops at 5 and 300 K. It was found that the solid solution Sr0.9Sm0.1Fe11.9Zn0.1O19at 300 K has specific saturation magnetization (?s ) and coercive force (?Hc) respectively by 0.4 and 9.7% higher than the base ferrite SrFe12O19