Intra-dot inter-layer magnetostatic coupling have been investigated in
trilayers which consist of two [Co/Pt] multilayers with out-of-plane
anisotropy and different coercivities separated by a thick Pt layer. For
single domain nanodots, the strong intra-dot inter-layer magnetostatic
interactions manifest as a shift of the soft layer hysteresis loop. The
amplitude of this shift decreases when the size of the dots is increased
and/or when the temperature is increased. Satisfactory agreement is found
between calculations and experimental results.