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X-ray diffraction, Raman spectroscopy and Mossbauer spectroscopy are used for investigating [Co.sub.x][Fe.sub.3-x][O.sub.4]-based nanoparticles, which are prepared by combustion reaction. The differences found in crystalline structure between the two phases have supported the evidence of a highly stressed core-shell interface, which has led to symmetry reduction of the tetrahedral and octahedral sites.

The article presents a new approach, which employs the pulsed laser deposition technique for the growth of various different epitaxial spinel ferrite films. The different growth modes exhibited by the films with different shapes at different temperatures are also analyzed.

The transmission, as well as the reflection techniques are employed to explain the magnetic permeability, as well as permittivity of the various metal strips coated ferrite disks. A modified measurement technique for determining the traditional transmission-reflection of these strips is also presented.

The significantly improved permeability and resonance frequency characteristics of metamaterial constructed by a Cu-wire coil wound on a ferrite core and controlled through varying the number of coil turns, N are reported. The special permeability spectrum shape and the dependence of permeability parameters on N for the metamaterial are demonstrated via use of an equivalent lumped parameter model.

Magnetization and Mossbauer spectroscopy measurements are carried out at low temperature under high field, on nanoparticles with a nickel ferrite core and a maghemite shell. The weak surface pinning condition of the nanoparticles has shown that the spin disorder is localized in the external shell and the decrease in underfield in the mean canting angle in the superficial shell is directly related to the unidirectional exchange anisotropy via the interface between the ordered core and the disordered shell.

The spectral properties of laterally coupled magneto ferrite-disk particles are studied. The studies have shown the existence of the exchange mechanism of interaction between the particles, which is distinctive from the magnetostatic interaction between classical magnetic dipoles and the electromagnetic interaction between small electromagnetic scatterers.

A free space millimeter water magneto-optical approach is used for the dielectric and magnetic characterization of ferrite materials. The frequency dependences of the magnetic permeability and dielectric permittivity on pure and diluted ferrites in millimeter waves are obtained.

Anatase titania-coated bismuth ferrite nanocomposites (BiFe[O.sub.3]/Ti[O.sub.2]) are prepared through a hydrothermal approach combined with a hydrolysis precipitation processing. The core-shell structured BiFe[O.sub.3]/Ti[O.sub.2] nanocomposites have displayed higher photocatalytic activity for photodegradation of Congo red under visible-light irradiation, which is attributed to the increase in the quantum efficiency by separating the electrons and holes effectively.

The high perpendicular coercivity of copper ferrite thin films is analyzed. The texture measurements have shown that the high perpendicular anisotropy of these films is attributed to the texture with the hard axis in the film plane.

An efficient route involving facile thermolysis of mixed metal-oleate complexes to form monodisperse ferrite nanocrystals is described. The approach is found to be extremely beneficial, as it gives nanocrystals with uniform composition.

A layer-by-layer growth scheme at atomic scale by which the percentage of Mn(super +) ions on the octahedral sublattice could be artificially controlled is described. Manganese ferrite films grown by this technique are found to exhibit different degrees of cation inversion when grown on {100} and {111} MgO substrates.

The exchange constants in spinel ferrites with S-state ions, including magnesium ferrite, lithium ferrite, and manganese ferrite, were calculated using modified Becke's three-parameter density functional. It is suggested that there may be an empirical universal law of parameters w (variable parameter) and alpha for spinel ferrites with S-states ions.

Accurate results for the complex permittivity, epsi=epsi' - jepsi' and permeability, mu=mu'-jmu' of barium ferrite powder and strontium ferrite powder in the frequency range from 8.0 to 26.5 Ghz is presented. The complex permittivity and permeability are determined via the waveguide transmission/reflection (TR) technique and the waveguide cavity resonator technique at 25 degree Celsius and relative humidity less than 75 %.

A study is conducted where high-precision high-field effective (HFE) linewidth measurements are made at 10 GHz on ultradense hot isostatic pressed and conventionally sintered (CS) yttrium iron garnet ferrite materials. In the case of the CS material, a microstructure-related increase related to conventional moderate wave number bulk-band spin waves is seen.

The conditions for partially coating SiO2 spheres with ferrite for three-dimensional magneto-photonic crystals are discussed. The ratio of Fe(super 3+)/Fe(super 2+) in the range of 50 percent to 100 percent and the pH value in the range of 8-10 is essential for the synthesis of sphere coated with Fe3O4 fine particles of 20 nm diameter.