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 χ (T) curves, frequency dispersion across Tf in ac susceptibility, and follows Vogel–Fulcher and power law type critical dynamics, 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 (AFM) ordering but also exhibits diffuse scattering due to the presence of short-range ordered AFM correlated spin clusters.