Investigation of the Influence of Raw Material Fe₂O₃ on the Magnetic Properties of Sr-ferrite Magnets

Abstract

The influence of specific surface area (SSA) of Fe 2 O 3 was investigated while evaluating the raw material of Sr ferrite preparation. For hard ferrite magnet, SSA of Fe 2 O 3 was found markedly affects the grain growth and the magnetic properties. Increasing of SSA of Fe 2 O 3 resulted in the increase of remanence (B R ) and (BH) max , but also causes a decline in intrinsic coercive force ( i H C ). The SSA of Fe 2 O 3 is most important factor in determining the reactivity of the ferrite specimens during calcinations and sintering processes. A larger SSA promotes reactivity, which results in larger grain size of either calcined or sintered powder, consequently larger B R and smaller i H C were achieved, whereas, the opposite trend was observed for small SSA of Fe 2 O 3 . Results are also confirmed that, when less impurity in Fe 2 O 3 , the microstructure and magnetic properties of Sr-ferrite have smaller sensitivity to the SSA of Fe 2 O 3 . As found in this study, well control of raw material Fe 2 O 3 is shown to be very critical in tailoring suitable B R and i H C for customized Sr-ferrite manufacturing process.

Synthesis and characterization of Fe2O3-Bi2O3-TiO2nanoparticles and its magnetic properties

“…They contain nanoparticles in at least one dimension which are smaller than 100 nm. These nanomaterials are coming into health care, electronics, cosmetics and other areas (1,2) . Due to many potential innovative applications, Nanoparticles research has received considerable attention.…”