Low temperature magnetic ground state in bulk Co0.3Zn0.7Fe2O4 spinel ferrite system: Neutron diffraction, magnetization and ac-susceptibility studies

The system under study is a bulk Co0.3Zn0.7Fe2O4 ferrite, synthesized by wet chemical route technique and having magnetic in-homogeneity at the microscopic scale, due to the concentration of magnetic ion at a tetrahedral site below the site percolation threshold for the ferrimagnetic ordering. To unravel the magnetic ground state of this system, low temperature neutron diffraction, magnetization and ac-susceptibility measurements were carried out. In the temperature-dependent neutron diffraction analysis, a diffused scattering signal appears at the low Q region below (1 1 1) magnetic Bragg peak at all temperature, indicating the presence of a finite magnetic cluster with infinite magnetic network. The diffused scattering signal intensity decreases with increases in magnetic field at T=10 K. The ac-susceptibility measurement exhibits three peak behavior in χ′ and χ″ indicating the presence of finite magnetic clusters and cluster–cluster interaction in the system. The absence of magnetic (2 0 0) peak in neutron diffraction at 2 K and bifurcation of zero field and field cooled magnetization indicate the phase transition from uniaxial random ferromagnetic (URF) phase to semi spin glass or canted random ferromagnetic (CRF) phase in the system with temperature.

► Co0.3Zn0.7Fe2O4 sample shows diffuse hump below magnetic (1 1 1) neutron Bragg peak.
► The absence of (2 0 0) diffraction peak at all temperatures.
► Neutron data shows that transverse components of moments are randomly oriented.
► At the low temperatures, a system shows canted random ferromagnetic phase.
► DC and ac-susceptibility data confirms the formation of magnetic clusters.