Intrinsic magnetism in BaTiO3 with magnetic transition element dopants (Co, Cr, Fe) synthesized by sol-precipitation method

A study of BaTiO3 nanoparticles doped with different transition metals including Co, Fe, and Cr is presented. X-ray diffraction and electron microscopy studies indicated that all the samples are highly crystalline and that transition metal dopants are successfully incorporated into BaTiO3 without detectable secondary phases. Raman spectra featured three characteristic broad bands centered approximately 300, 520, and 715 cm(-1) from the tetragonal BaTiO3 without any extra peak present that may be attributed to other impurity phases. Temperature-and field-dependent magnetometry measurements and analysis revealed that all the samples show paramagnetic-like behavior originating from the transition metal ions. These results not only allow the exclusion of potential secondary ferromagnetic or antiferromagnetic phases, but also suggest that transition metal ions (Co, Cr, and Fe) in BaTiO3 shown in this study are present as isolated paramagnetic centers. (C) 2011 American Institute of Physics. [doi:10.1063/1.3556768]