Colossal magnetostriction effect in HoMn<Subscript>2</Subscript>O<Subscript>5</Subscript>

We have investigated the detailed field and temperature dependence of the dielectric constant, electric polarization, magnetization and magnetostriction in orthorhombic HoMn<Subscript>2</Subscript>O<Subscript>5</Subscript> single crystals. HoMn<Subscript>2</Subscript>O<Subscript>5</Subscript> displays incommensurate antiferromagnetic ordering below 39 K, becoming commensurate on further cooling. The commensurate-incommensurate transition takes place at low temperatures. The inherent magnetic frustration in this material is lifted by a small lattice distortion, primarily involving shifts of the Mn<Superscript>3+</Superscript> cations and giving rise to a canted antiferroelectric phase. Colossal magnetostriction effect was observed and a novel phase transition diagram was build. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2006