Magnetic properties of a partially inverted zinc ferrite synthesized by a new coprecipitation technique using urea

Nanosized zinc ferrite powder has been prepared by a new coprecipitation technique using urea. A single phase crystalline 13 nm zinc ferrite powder is obtained by heating a mixed zinc and iron salt solution with urea in a nitrogen atmosphere at about 100 degreesC for 2 minutes followed by 20 minutes heating at 80 degreesC before being cooled to room temperature. The powder shows an unusually high saturation magnetization of about 21 emu/g at room temperature and about 53 emu/g at 10 K. Mossbauer studies show magnetic ordering in the powder even at room temperature. It also indicates the presence of non-inverted, nanosize, paramagnetic fraction. The Mossbauer parameters and the Neel temperature of this fraction are different from the standard values for bulk zinc ferrite. (C) 2003 Elsevier Science B.V. All rights reserved.