Thick coatings of CoTi-substituted Ba hexaferrite with thenominal composition BaCoTiFe10O19 were prepared using atmosphericplasma-spraying technology. The coatings were preparedfrom prereacted powders of the desired composition. Theas-deposited coatings showed a high degree of crystallinity. Adetailed investigation of the coatings’ phase compositions wasconducted with micro-Raman spectroscopy and energy-dispersiveX-ray spectroscopy. Two magnetic ferrite phases, CoTisubstitutedBa hexaferrite and Co ferrite, were identified in thecoatings. An X-ray powder-diffraction analysis and a quantitativestructural analysis based on Rietveld refinement showed thatthe mass ratio of the two phases and their chemical compositionvaried with respect to the spraying parameters. Consequently,the static and microwave magnetic properties of the as-sprayedcoatings also varied. We were able to explain the formationof the two ferrite phases based on the interplay between thepartial melting of the feedstock powder and the recrystallizationkinetics.
Magnetic phase formation in CoTi-substituted Ba hexaferrite coatings prepared with atmospheric plasma spraying / D., Lisjak; Bolelli, Giovanni; Lusvarghi, Luca; M., Bégard; M., Bruehl; K., Bobzin; P., Lintunen; U., Kanerva; M., Pasquale; M., Drofenik. - In: JOURNAL OF THE AMERICAN CERAMIC SOCIETY. - ISSN 0002-7820. - STAMPA. - 93:(2010), pp. 2579-2584. [10.1111/j.1551-2916.2010.03770.x]