Structural characterization and ferromagnetic properties in Ga3+ doped α-Fe2O3 system prepared by coprecipitation route and vacuum annealing

Structural and magnetic properties of alpha-Fe2-xGaxO3 system in the range of low Ga content (x=0.28-0.60) have been discussed in the present work. The samples with nanometer grain size have been prepared by coprecipitation of the metal hydroxides at high alkaline medium. The as prepared samples have been annealed at 800 degrees C under vacuum. Synchrotron X-ray diffraction pattern of the samples has been used to confirm rhombohedral structure with space group R (3) over barC, along with extra phase less than 2% of the rhombohedral phase. Raman active phonon modes are consistent with the spectrum of rhombohedral structure in alpha-Fe2O3. Raman spectra revealed structural disorder at microscopic level due to doping effect. The samples of alpha-Fe2-xGaxO3 system exhibited ferromagnetic properties and magnetization showed increasing trend with the increase of Ga content. Low temperature x-ray diffraction pattern and magnetization have been studied for the sample with x=0.6 to test the correlation between structure and ferromagnetic parameters. (C) 2014 AIP Publishing LLC.