Search

The study of the structural, morphology and magnetic properties of Zn0.5Co0.5Fe2O4ferrite is the objective of this work. The sample was prepared by hydrothermal method and was characterized by X-ray diffraction (XRD), (SEM) and (TEM) micrographs and magnetization measurements. The magnetic hysteresis loops, field cooling (FC) and zero field cooling (ZFC) curves, in temperature range (0-400K), were measured using XL-SQUID magnetometer and the values of blocking temperatures (TB) were determined. The results indicated that Zn0.5Co0.5Fe2O4sample were formed in a single spinel phase and gives the value for the lattice parameter (8.3952 Å) and nanosizes of particles (13.8 nm) were compared with these obtained from ZnFe2O4sample prepared also by synthesis method (8.4261 Å and 14 nm). Although, the superparamagnetic behaviour for Co-Zn ferrite has observed at 350K with a blocking temperature (TB= 300K), that is maximum at the value obtained in the case of Zn-ferrite (TB= 12K). [ABSTRACT FROM AUTHOR]

Abstract: Divanadates of general formula ZnMV2O7 (M=Co, Ni and Cu) have been prepared as powdered samples and the X-ray structural determination and magnetic studies have been carried out. Both ZnCoV2O7 and ZnNiV2O7 crystallize with the so-called dichromate structure type, showing monoclinic symmetry, space group P21/c, while the third member of this family of vanadates ZnCuV2O7 shows the thortveitite structure type with monoclinic symmetry, space group C2/c. Magnetic susceptibility and specific heat measurements reveal that these derivatives behave as antiferromagnets and the estimated Néel temperatures are 4.5, 3.5 and 5.3K for cobalt, nickel and copper vanadates, respectively. In all cases, the one-dimensional magnetic behavior that present the M2V2O7 vanadates is broken down when the magnetic cation M is half replaced by the diamagnetic Zn2+ to give the ZnMV2O7 samples studied in the present work. [Copyright &y& Elsevier]