The magnetic properties of porous Ni-Zn ferrites prepared from wood templates

Abstract

The crystallographic and magnetic properties of porous NixZn1-xFe2O4 (x = 0.1, 0.5 and 0.9) from wood templates were investigated in this study. The nitrates aqueous precursor solution was infiltrated into the wood specimen at 60°C to retain the original shape and the microstructure of wood. The sintered bodies contained elongated pores enclosed by a thin layer of wall with the thickness about 1-2 μm. The grain size of polycrystalline ferrite was observed to be in the range of 1-1.5 μm. Each grain was horizontally connected to form polycrystalline walls of single-layered grains. The VSM measurement showed that there is an obvious difference of magnetic properties in the parallel and perpendicular direction due to the anisotropic structure of wood template. The coercivity perpendicular to the pores orientation was larger compared to the coercivity parallel to the pores orientation. It is also discovered that the optimum saturation magnetization was achieved at x = 0.5.

Fabrication and characterization of nanostructured Ba-doped BiFeO3 porous ceramics

“…On the other hand, the coercive field (H c ) increased from 284 to 380 kA/m with increasing porosity. The relatively high H c value of BBU porous sample obtained in this work is higher than those reported for doped bismuth ferrites bulk [22][23][24] or other porous ferrites [36,37].…”

Magnetic wood-based biomorphic Sr3Co2Fe24O41 Z-type hexaferrite ecoceramics made from cork templates

“…Singh has since reported the formation of both carbides and oxides [9]. However, to date the only magnetic oxide ecoceramics produced appear to be the spinel oxides Mn x Zn 1Àx Fe 2 O 4 [11] and Ni x Zn 1Àx Fe 2 O 4 [12], and the hexagonal ferrites BaFe 12 O 19 [13] and Sr 1Àx La x Fe 12Àx Co x O 19 [14], all made using nitrate salt solutions to infiltrate the pyrolised wood, with subsequent heating in air. The wood-templated 500 nm diameter SrZnCoFe 16 O 27 W ferrite rods made in Ref.…”

Porous Ba Ferrite Prepared from Wood Template

“…Randomly oriented crystalline structure resulted in the isotropic hysteresis loops. For the case of soft magnetic Ni-Zn ferrite wood, the direction to the porous structure gave the influence for the magnetic anisotropy [7]. The magnetization tends to saturate easily in the magnetic field along the pore structure.…”

“…This presents a possibility that the microstructure gives an increase of the permeability of ferrite materials in the GHz frequency region. We already reported the synthesis of a porous Ni-Zn ferrite from a wood template and found different magnetic properties depending on the axis along the 1-dimesional pore structure [7]. We are expecting that thin film-like magnetic properties of the porous ferrite increase the permeability in the high frequency region.…”