  The mechanics of complex bodies with memory effects is discussed in
linearized setting. The attention is focused on the characterization of free
energies in terms of minimum work and maximum recoverable work in the bulk and
along a discontinuity surface endowed with its own surface energy, a surface
internal to the body. To this aim, use is made of techniques proposed by Del
Piero. Consequences of the Clausius-Duhem inequality are investigated for
complex bodies with instantaneous linear elastic response.
