Nanometric Co-10 at% Cr alloy-cluster assembled films have been produced by
a plasma-gas-condensation method, and examined by transmission electron mi
croscopy and the magneto-optical Kerr effect. With increasing the average w
eight thickness t we found that the Co-Cr clusters coalesce to form a large
network. This formation took place more rapidly among clusters with an ave
rage cluster size of d = 2.4 nm than with those of d = 4.6 nm. The isolated
Co-Cr clusters are superparamagnetic when t < 2 nm. With increasing t, the
transition from superparamagnet to ferromagnet occurs more rapidly in the
system with d = 2.4 nm than in that with d = 4.6 nm, in accordance with the
ir morphological characteristics.