Thermal plasma synthesis of zinc ferrite nanopowders

Nanosized zinc ferrite spinel powders of various compositions were produced in a radiofrequency (RF) thermal plasma from oxide mixtures and from co-pr ecipitated hydroxides. Bulk and surface chemical compositions of the produc ts were measured by ICP-AES and XPS. Phase conditions were determined by XR D. Morphology was investigated by SEM and TEM. In spite of the short reside nce time of reagents in the plasma reactor, a high degree of spinel formati on was achieved. The Zn enrichment on the surface determined by quantitativ e XPS is attributed to a thin ZnO layer on the surface of the zinc ferrite particles. In zinc ferrous ferrites. an inhomogeneous distribution of Zn in side the grains may also exist. (C) 2001 Elsevier Science B.V. All rights r eserved.