Structural and magnetic properties of single-crystalline Co-doped barium titanate nanoparticles

Undoped and Co-doped BaTiO(3) nanoparticles were synthesized by a one-step sol-precipitation method. For all the samples, X-ray diffraction showed characteristic diffraction lines for BaTiO(3) without the indication of secondary phases. High-resolution transition electron microscopy images showed that BaTiO(3) nanoparticles exhibit the nature of single-crystal. Magnetometry revealed that all the Co-doped BaTiO(3) samples show paramagnetic behaviors and Co ions in BaTiO(3) are present as isolated paramagnetic centers. This is contrasted to several reported cases of ferromagnetism in Co-doped BaTiO(3). (C) 2009 Elsevier B.V. All rights reserved.