Crystal Structure, Magnetic and Photocatalytic Properties of Solid SolutionsBi_(2-x)LaxFe4O9 (x=0.05, 0.1)

摘要

Solid solutions Bi_(2-x)LaxFe4O9 at small x-values (x = 0.05, 0.1) were synthesized by the solid-state reaction method. Here larger Bi~(3+) ions were partially substituted by smaller La~(3+) ions. It is shown that the above solid solutions had an orthorhombic mullite-type crystal structures. Crystal lattice parameters of solid solutions were very close to the respective parameters for pure Bi2Fe4O9 ferrite. It was determined that the substitution of Bi~(3+) ions by La~(3+) ions in Bi2Fe4O9 leads to the increase of specific magnetizations of the samples. All studied samples were antiferromagnets with Neel temperatures TN of 258 K, 246 K, ~243K for x = 0, 0.05, 0.1 respectively. Hence at the substitution of Bi~(3+) ions by La~(3+) ions, TN decreases. It is shown that solid solution Bi_(1.9)La_(0.1)Fe4O9 had good photocatalytic activity for the oxidation of Acid Telon Blue dye in the aqueous solution under visible light irradiation.