Ni1-xZnxFe2 O-4 (0.0 less than or equal to x less than or equal to 1.0) nan
oparticles have been prepared by the polyvinyl alcohol (PVA) sol-gel method
. The lattice parameter of Ni-Zn nanoparticle is larger than that of the bu
lk material. The Mossbauer spectra of the samples showed the presence of ul
trafine particles exhibiting superparamagnetic relaxation at room temperatu
re and an ordered magnetic structure at 77 K. (C) 2001 Elsevier Science B.V
. All rights reserved.