ZnFe₂O₄ Nanocrystals:  Synthesis and Magnetic Properties

Abstract

Ferromagnetic zinc ferrite nanocrystals at ambient temperature were synthesized via the thermal decomposition of metal-surfactant complexes. Characterization measurements including transmission electron microscopy and X-ray diffraction were performed for as-synthesized ZnFe 2 O 4 particles. The sample has a relatively narrow size distribution with an average particle size of 9.8 ( 0.2 nm and standard deviation of 30%. The assynthesized zinc ferrite nanocrystals are superparamagnetic at room temperature with a blocking temperature T B ) 68 ( 2 K and a saturation magnetization M S ) 65.4 emu‚g -1 at T ) 10 K, which are caused by the change in the inversion degree of the spinel structure. A coercive field of H C ) 102 ( 5 Oe in the blocked state indicates small particle anisotropy, although evidence of surface spin canting was inferred from magnetization data in the as-synthesized ZnFe 2 O 4 nanocrystals. Our results demonstrate that magnetic properties of magnetic particles can be largely modified by just changing particle size, which might be a useful way to design novel magnetic materials.

Fabrication, characterization, and magnetic behavior of porous ZnFe2O4 hollow microspheres

“…Among the family of ferrite materials, zinc ferrite (ZnFe 2 O 4 ) has a normal spinel structure with the tetrahedral A sites preferentially occupied by Zn 2? and octahedral B sites occupied by Fe 3? , which results in anti-ferromagnetic properties at T N = 10 K [2].…”

Structural characterization and magnetic properties of superparamagnetic zinc ferrite nanoparticles synthesized by the coprecipitation method

“…Several methods such as ball milling [11], sol-gel [12], coprecipitation [13], hydrothermal [14] auto-combustion route [15] and ultrasonic cavitation [16] have been used to synthesize and investigate the magnetic properties of zinc ferrite nanoparticles. However, the coprecipitation is a simple technique to synthesize the ferrite nanoparticles at low temperatures and often without calcination at high temperatures.…”

Effect on Magnetic Properties of Zinc Doped Nano Ferrites Synthesized by Precursor or Method

“…Nanocrystalline Cu-Zn ferrite have been extensively investigated due to their potential applications in non-resonant device, radio frequency circuits, rod antennas, high quality filters, transformer cores, read/write heads for high speed digital tapes and operating devices (Pradan et al, 2008;Lamani et al, 2009). (Yao et al, 2007). Zn-substitution results to a change of cations in chemical composition and a different distribution of cations between A and B sites.…”