The claviform BaFe12O19 crystals were synthesized by the precipitation-toptactic reaction method using α-FeOOH and γ-FeOOH as raw materials respectively.The synthesis processes of BaFe12O19,studied by XRD,SEM,EDS,FT...The claviform BaFe12O19 crystals were synthesized by the precipitation-toptactic reaction method using α-FeOOH and γ-FeOOH as raw materials respectively.The synthesis processes of BaFe12O19,studied by XRD,SEM,EDS,FT-IR,and TG-DTA techniques,included preparations of precursor γ and precursor α,formations of α-Fe2O3 and BaFe2O4,and production of rod-like BaFe12O19 through dehydroxylation of pod-like FeOOH,followed by reactions of α-Fe2O3 with BaCO3 and BaFe2O4.The crystallinity of α-Fe2O3 and BaCO3 from precursor α was better than from precursor γ due to the direct dehydroxylation of α-FeOOH,resulting in a lower nucleation rate and better crystallinity of BaFe2O4.BaFe12O19 prepared from precursor α showed lower crystallinity and purity with a higher length-diameter ratio than from precursor γ.The VSM results proved that the appearance of final products had an important influence on magnetic properties.展开更多
文摘The claviform BaFe12O19 crystals were synthesized by the precipitation-toptactic reaction method using α-FeOOH and γ-FeOOH as raw materials respectively.The synthesis processes of BaFe12O19,studied by XRD,SEM,EDS,FT-IR,and TG-DTA techniques,included preparations of precursor γ and precursor α,formations of α-Fe2O3 and BaFe2O4,and production of rod-like BaFe12O19 through dehydroxylation of pod-like FeOOH,followed by reactions of α-Fe2O3 with BaCO3 and BaFe2O4.The crystallinity of α-Fe2O3 and BaCO3 from precursor α was better than from precursor γ due to the direct dehydroxylation of α-FeOOH,resulting in a lower nucleation rate and better crystallinity of BaFe2O4.BaFe12O19 prepared from precursor α showed lower crystallinity and purity with a higher length-diameter ratio than from precursor γ.The VSM results proved that the appearance of final products had an important influence on magnetic properties.
