  We have found the exact (factorized) ground state of a general class of
ferrimagnets in the presence of a magnetic field which covers the frustrated,
anisotropic and long range interactions for arbitrary dimensional space. In
particular cases, our model represents the bond-alternating,
ferromagnet-antiferromagnet and also homogeneous spin $s$ model. The factorized
ground state is a product of single particle kets on a bipartite lattice
composed of two different spins ($\rho, \sigma$). The spin waves analysis
around the exact ground state show two branch of excitations which is the
origin of two dynamics of the model. The signature of these dynamics is
addressed as a peak and a broaden bump in the specific heat.

Statistical Mechanics;Strongly Correlated Electrons;Quantum Physics