Effect Of Mn Substitution Research Articles

Characterization of Goethite and Hematite in a Tunisian Soil Profile By Mössbauer Spectroscopy

AbstractAs part of the characterization of a Tunisian red soil profile, six samples, taken at different depths, were investigated by Mössbauer spectroscopy at room temperature and at 80 K to obtain information about the various types of Fe oxides present. By considering magnetic hyperfine field distributions, the spectra of goethite and hematite were well resolved. Chemical analyses of the samples revealed a partial substitution of Fe by Al and Mn. The spectral behavior of the goethite was predominantly influenced by crystallinity and amount of Al substitution which resulted in a reduction of the magnetic hyperfine field. The effect of Mn substitution was much more pronounced in the hematite spectrum as a consequence of a stronger suppression of the Morin transition by Mn than by Al.

The status of chromium plating

In present work, a series of Ba2Co2−xMnxFe12O22 nanoparticles (x = 0.0, 0.1, 0.3, 0.5, 0.7, and 0.9) has been synthesized by hydrothermal method. Effect of Mn substitution on structural, microstructure and magnetic properties has been investigated in detail. X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) analyses confirmed the formation of Y-type hexagonal ferrite structure. Morphology and chemical composition studies performed by Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) spectroscopy conformed that with increasing Mn concentration grain size increases from few nanometers to micrometer range. Furthermore, magnetic analyses revealed that with increasing Mn concentration at octahedral and tetrahedral sites the coercivity and squareness were found to increase from 455Oe to 2550Oe, and 0.26 to 0.56, respectively. Theoretical approach was also used to calculate saturation magnetization of synthesized samples. The synthesized nanoparticles with enhanced magnetic characteristics are ideal candidate for their use in perpendicular magnetic recording and high frequency applications.