Mössbauer spectroscopy and magnetic susceptibility studies of Cr–Al substituted strontium ferrite particles Available to Purchase

Substituted strontium ferrite $SrFe12−xCrx/2Alx/2O19$ $(x=0–2.5)$ was prepared by sol-gel method. Ac susceptometer, and $F57e$ Mössbauer spectroscopy were used to analyze the structure, static and dynamic magnetic properties of the prepared samples. Mössbauer spectra show that Al–Cr ions preferentially occupy the $12k$ sites. Magnetic dynamics of the samples was studied by the measurement of ac magnetic susceptibility versus temperature at different frequencies and dc magnetic fields. A frequency-dependent peak was observed in ac magnetic susceptibility versus temperature, which is well described by Vogel–Fulcher model. It was observed that with increasing substitutions, blocking temperature is decreased.