  The proximity effect in mesoscopic ferromagnet/superconductor ($FS$) Ni/Al
structures of various geometries was studied experimentally on both $F$- and
$S$-sides of the structures. Samples with a wide range of interface
transparency were fabricated. The dependence of the effect on $FS$ interface
transparency was investigated. The amplitude of this effect was found to be
larger than expected from classical theory of proximity effect. Preliminary
experiments showed no phase-sensitive oscillations in Andreev interferometer
geometry. Various theoretical models are discussed.
