Effect of Zn for Ni substitution on the properties of Nickel-Zinc ferrites as studied by low-energy implanted positrons

Abstract

Abstract Samples of Nickel-Zinc ferrite, Ni1−xZnxFe2O4 (x\u202f=\u202f0.0, 0.2, 0.4, 0.6, 0.8 and 1.0), were synthesized by a solid state reaction method. The morphology of four of the samples (x\u202f=\u202f0.0, 0.4, 0.6 and 1.0) was observed with 3D X-ray imaging. The distortion caused by the increase of zinc in the ferrite structure and the respective movement of the trivalent (Fe) and divalent (Ni) ions from the tetrahedral- to the octahedral-sites cause some vacancies which act as positron traps. Doppler broadening of annihilation radiation experiments have been performed with a variable energy monoenergetic positron beam. The positron results as a function of the energy/depth implantation are presented in this work.