Current Applied Physics, Vol.14, No.7, 970-979, 2014
Study of low temperature ferromagnetism, surface paramagnetism and exchange bias effect in alpha-Fe1.4Ga0.6O3 oxide
The compound alpha-Fe1.4Ga0.6O3 has been prepared by mechanical alloying of alpha-Fe2O3 cc and beta-Ga2O3 and subsequent heating under vacuum condition. X-ray diffraction, Raman and Mossbauer spectroscopy confirmed stabilization of the material in rhombohedral phase. A remarkable change in the magnetic ordering has been found by substitution of non-magnetic Ga atoms in alpha-Fe2O3. a. The ferromagnetism in alpha-Fe1.4Ga0.6O3 is found to be more soft and enhanced in comparison to alpha-Fe2O3. The samples also exhibited features of exchange bias, low temperature surface paramagnetism, and suppression of Morin transition. Nano-sized grains and alloying process of the material affected these features up to certain extent. The results of magnetic measurements are highly interesting for designing metal doped alpha-Fe2O3 cc based ferromagnet for room temperature applications. (C) 2014 Elsevier B.V. All rights reserved.