Crossover from meta-magnetic state to spin-glass behaviour upon Ti-substitution for Mn in CuMn2O4

Tetragonal distorted spinel of CuMn2-xTixO4 (x = 0, 0.25 and 0.50) was prepared by solid state reaction method followed by neutron diffraction, FTIR spectroscopy, dielectric spectroscopy and magnetization measurements. The neutron diffraction and FTIR spectroscopy provide the information regarding phase formation. But, the magnetic susceptibility clearly shows the ferri-magnetic order below 76K associated with meta-magnetic state which turns to spin-glass behaviour upon Ti-substitution for Mn in CuMn2O4. In addition, the room temperature M(H) of all the spinels are described by the Arrott's plot for weak ferromagnetism. Further, the room temperature dielectric measurement provides the electronic property of CuMn2O4 dominated by grain boundary effect that is significantly increased upon Ti-substitution for Mn in CuMn2O4.