The effect of yttrium on the microwave absorbing properties of Fe78Si13B9 alloy powders.

• Fe 78-x Si 13 B 9 Y x alloy powders with excellent absorbing properties were prepared. • The mechanism of yttrium's influence on absorbing performance was explored. • The minimum interference thickness at 0.3 GHz decreased by 56.5%. • The performances were due to synergistic effects of components and structure. In this study, the effect of rare earth Y on the microwave absorbing properties of the powders was studied, directing against low electromagnetic loss (tanδ) and low dielectric constant of Fe 78 Si 13 B 9 alloy powders in the frequency band of 0.3–3 GHz. The results showed that when Y content is less than 2 at%, Y solid dissolves in dendrite gap of α-Fe, forming interstitial solid solution. With the increase of Y content, the permeability and dielectric constant of Fe 78-x Si 13 B 9 Y x alloy powders increase, especially the dielectric loss and magnetic loss increase significantly. Fe 76 Si 13 B 9 Y 2 alloy powders have excellent absorbing properties. When the frequency is 0.3 GHz and 1 GHz, the loss tangent value of that is as high as 5.22 and 2.42 respectively, and the minimum interference thickness is reduced to 11.81 mm and 5.20 mm, which is 45% of that of Fe 78 Si 13 B 9 alloy powders. Fe 76 Si 13 B 9 Y 2 alloy powders has excellent electromagnetic loss absorption and interference absorption properties at the same time. [ABSTRACT FROM AUTHOR]