Freezing of short-range ordered antiferromagnetic clusters in the CrFeTi2O7 system
Abstract
We report on the CrFeTi2O7 (CFTO) system using a combination of x-ray diffraction, dc magnetization, ac susceptibility, specific heat and neutron diffraction measurements. CFTO is seen to crystallize in a monoclinic P21/a symmetry. It shows a glassy freezing at Tf ~ 22 K, characterized by the observation of bifurcation between ZFC and FC (T) curves, frequency dispersion across Tf in ac susceptibility, appearance of non-zero remanent magnetization and coercivity below Tf, very slow relaxation of iso-thermal remanent magnetization with time and a linear temperature dependence of magnetic contribution to specific heat Cm below Tf. The microscopic neutron diffraction analysis of CFTO not only confirms the absence of long-range antiferromagnetic ordering but also exhibits diffuse scattering due to the presence of shortrange ordered antiferromagnetically correlated spin clusters.