High frequency characteristics of Fe65Co35 alloy cluster-assembled films prepared by energetic cluster deposition.

ABSTRACT

Size-monodispersed Fe65Co35 alloy clusters whose average sizes ranged from 7 to 12 nm were produced by a plasma-gas-condensation (PGC)-type cluster deposition apparatus. Fe65Co35 alloy cluster-assembled films were further prepared at room temperature by energetic cluster deposition method. Positively charged clusters in a cluster beam were accelerated electrically and deposited onto a negatively biased substrate together with neutral clusters from the same cluster source, leading to the formation of a high-density Fe65Co35 alloy cluster-assembled films with good soft magnetic properties. High frequency magnetic characteristics of these films were studied at room temperature using a high-frequency permeameter (RMF-3000, Ryowa). The real part (micro') of permeability for the Fe65Co35 alloy cluster-assembled films prepared at bias voltage V(a) = -20 kV has a large value of micro' = 135 at f = 1.5 GHz, and imaginary part (micro") of permeability has a maximum (micro" approximately 190) at about 2.5 GHz.