We have measured the magnetoresistances in approximate to 30-Angstrom-
thick fine Cu-particle and Au-doped Cu-particle (CuAu-particle) films
between 2.1 and 4.2 K and in magnetic fields H up to 6 T, with sheet r
esistances R(square)(4.2 K) of the films ranging from approximate to 1
0 k Omega to 2 M Omega. We find that the magnetoresistances are positi
ve, exhibiting broad maxima, at low H, while they can change sign and
become negative at high H. The magnitudes of the normalized magnetores
istances, Delta R(square)(H)/R(square)(0) = [R(square)(H) - R(square)(
0)]/R(square)(0), are of the order of a tenth of a percent, depending
on the values of R(square). Particularly, the magnetoresistances in pu
re Cu-particle films are essentially isotropic, regardless of the orie
ntation of H being applied parallel or perpendicular to the film plane
. In CuAu-particle films, however, more negative perpendicular magneto
resistances relative to parallel magnetoresistances are observed. Ther
e observations are closely connected with the fine-particle structure
of our films. Explanation for our experimental results in terms of cur
rent theories is presented.