  Recently we have reported the observation of colossal magnetostriction effect
in HoMn2O5 single crystals. Besides we have made the supposition for possible
correlation between the peculiarities, observed in the field depended
polarization measurements, and the colossal magnetostriction effect at a 4.2 K
temperature. In this article we present our results received by polarization
and magnetostriction measurements on HoMn2O5 and TbMn2O5 single crystals and
the strong correlation between magnetostriction and polarization phase
transition for these two compounds. The origin of this correlation is
discussed.
