Crystallographic and magnetic identification of secondary phase in orientated Bi 5Fe 0.5Co 0.5Ti 3O 15 ceramics
Comyn, T. P.
Ward, M. B.
Brown, A. P.
Harrington, J. P.
Pemble, Martyn E.
Whatmore, Roger W.
The fabrication of highly-oriented polycrystalline ceramics of Bi 5Fe 0.5Co 0.5Ti 3O 15, prepared via molten salt synthesis and uniaxial pressing of high aspect ratio platelets is reported. Electron backscatter images show a secondary phase within the ceramic which is rich in cobalt and iron. The concentration of the secondary phase obtained from scanning electron microscopy is estimated at less than 2% by volume, below the detection limit of x-ray diffraction (XRD). The samples were characterized by x-ray diffraction, polarization-electric field measurements, superconducting quantum interference device as a function of sample orientation and vibrating sample magnetometry as a function of temperature. It is inferred from the data that the observed ferromagnetic response is dominated by the secondary phase. This work highlights the importance of rigorous materials characterisation in the study of multiferroics as small amounts of secondary phase, below the limit of XRD, can lead to false conclusions.
Molten salts , Ferromagnetic materials , Materials properties , Curie point , Ceramics , Curie temperature , Ferrite , Nanostructures
Palizdar, M., Comyn, T. P., Ward, M. B., Brown, A. P., Harrington, J. P., Kulkarni, S., Keeney, L., Roy, S., Pemble, M., Whatmore, R., Quinn, C., Kilcoyne, S. H. ,Bell, A. J. (2012) 'Crystallographic and magnetic identification of secondary phase in orientated Bi5Fe0.5Co0.5Ti3O15 ceramics'. Journal of Applied Physics, 112 , 073919. http://scitation.aip.org/content/aip/journal/jap/112/7/10.1063/1.4754562
© 2012 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. The following article appeared in J. Appl. Phys. 112, 073919 (2012) and may be found at http://scitation.aip.org/content/aip/journal/jap/112/7/10.1063/1.4754562