LAUSR

Abstract Ac and dc magnetic measurements have been performed on CuMnO2. From both the magnetic data the existence of Griffith-like phase established. Both ac and dc magnetic studies demonstrate aspects of Griffith phase-like behavior. The onset of Griffith like phase is associated with an effective slowing down. The presence of short range ferromagnetic ordering is observed above the antiferromagnetic transition temperature. Different directions in the triangular ab plane in CuMnO2 become inequivalent: there exist for each Mn two short and four long Mn Mn distances in the plane. The exchange interaction at short bonds is stronger, which, with the uniaxial magnetic anisotropy of Mn3+(spins are oriented predominantly along the long Mn O bonds), leaves the system frustrated. This frustration may induce the Griffith-like phase.