• Media type: E-Article
  • Title: Novel magnetoelectric composites of cobalt iron alloy and barium titanate
  • Contributor: Walther, Till; Köferstein, Roberto; Ebbinghaus, Stefan G.
  • Published: Wiley, 2017
  • Published in: Journal of the American Ceramic Society, 100 (2017) 4, Seite 1502-1507
  • Language: English
  • DOI: 10.1111/jace.14744
  • ISSN: 1551-2916; 0002-7820
  • Origination:
  • Footnote:
  • Description: AbstractMagnetoelectric barium titanate ceramics with embedded cobalt iron alloy particles (Co1/3Fe2/3)x–(BaTiO3)(1−x), with x=0.2, 0.4, and 0.6, were prepared by a polyol‐mediated synthesis with subsequent sintering in a reducing forming gas atmosphere. The samples were characterized by XRD and SEM/EDX measurements. The sizes of the Co1/3Fe2/3 grains increase with x. Impedance spectroscopy showed a behavior similar to pure BaTiO3, in particular the occurrence of the ferroelectric‐paraelectric phase transition, and high permittivities for the sample with x=0.6, that is, near the percolation threshold. The samples exhibit soft ferromagnetic properties with large saturation magnetizations of 2.5 μB/atom and narrow hystereses. Detailed magnetoelectric investigations revealed a unique DC‐field dependence of αME for all three compositions. Most remarkably, the sample with x=0.4 possesses a broad ME hysteresis and an inversion of the sign of αME at 5 kOe.